Dissertations / Theses: 'Heat pipe solar collector'

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Zhao, Xudong. "Investigation of a novel heat pipe solar collector/CHP system." Thesis, University of Nottingham, 2003. http://eprints.nottingham.ac.uk/11255/.

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The European Union has an ongoing commitment to reducing CO2 emission as highlighted by its agreement at the Kyoto Summit. One approach to achieving these reductions would be to develop alternative energy sources for major energy demanding sectors. In the EU, about 40% of all energy consumed is associated with buildings and of this, about 60% is utilised in the housing sector. A major part of the energy demand of buildings could be met by utilising renewable energy sources, e.g. solar energy. Existing large-scale plants for power generation prevent efficient utilisation of the waste hot water produced. This means that to meet electricity demand, vast quantities of fossil fuels are burnt releasing unwanted pollutants (e.g., CO2 and NOx) into the atmosphere. Over the last decade, small-scale CHP plants have been introduced for many applications with proven environmental and economic benefits. In addition, solar energy has been used to generate electricity and provide hot water in conjunction with the CHP plants. Investigation of a hybrid heat pipe solar collector/CHP system was carried out in this research. The system is powered by solar and gas energy as well as the boiler waste heat to provide electricity and heating for residential buildings. Compared to the relevant system configurations, this system has the following innovative features: The solar collector was integrated with exhaust flue gas channels that allowed both solar energy and waste heat from exhaust gas to be utilised. Heat pipes as high efficiency heat transfer devices were incorporated in the collector panel. Both miniature and normal heat pipes were investigated, and this resulted in two types of collectors, e.g., thin membrane heat pipe solar collector, and hybrid heat pipe solar collector, to be produced for this application. A compact, lightweight turbine was applied in this system. Novel refrigerants, including n-pentane and hydrofluoroethers (HFEs), were employed as the working fluids for the CHP system. Use of the system would save primary energy of approximately 3,150kWh per year compared to the conventional electricity and heating supply systems, and this would result in reduction of CO2 emission of up to 1.5 tonnes. The running cost of the proposed system would also be lower. The research initially investigated the thermal performance of several heat pipes, including micro/miniature heat pipes, normal circular and rectangular heat pipes, with/without wicks. An analytical model was developed to evaluate the heat transport capacity for these heat pipes. A miniature heat pipe with parallel piped channel geometry was proposed. The variation of heat transport capacity for either micro/miniature or normal heat pipes with operation temperature, liquid fill level, inclination and channel geometry were investigated. Investigation of the operating characteristics of the selected heat pipes, e.g., two miniature and one mini heat pipes, and two normal heat pipes, was then carried out using both the numerical technique and experimental testing. It was found that the results from tests were in good agreement with the numerical predictions when the test conditions were close to the simulation assumptions. The research work further involved the design, modelling, construction and tests of two innovative heat pipe solar collectors, namely, the thin membrane heat pipe solar collector and the hybrid heat pipe solar collector. A computer model was developed to analyse the heat transfer in the collectors. Two collector efficiencies, η and η1, were defined to evaluate their thermal performance, which were all indicated as the function of a general parameter (tmean-ta)/In. Effects of the top cover, manifold as well as flue gas temperature and flow rate (for hybrid collector only) on collector efficiencies were investigated using the computer model developed. Laboratory tests were carried out to validate the modelling predictions and experimentally examine the thermal performance of the collectors. Comparison was made between the modelling and testing results, and the reasons for error formation were analysed. The research then considered the issues of the micro impulse-reaction turbine, which was another part of the integrated system. The structure configuration, coupling pattern with the generator as well as internal geometry contour of the turbine were described. The velocity, pressure and turbulent kinetic energy of the flow in the turbine were determined using numerical CFD prediction. In addition, experimental tests were carried out using a prototype system. The results of CFD simulation and testing show good agreement. This indicates that CFD can be used as a tool of optimizing turbine geometry and determining operating conditions. The research finally focused on the integrated system which brought the heat pipe solar collector, boiler and micro turbine together. The individual components, configurations and layout of the system were illustrated. Theoretical analysis was carried out to investigate thermodynamic cycle and heat transfer contained in the combined system, which is based on the assumption that the system operated on a typical Rankine cycle powered by both solar and gas energy. Tests for the prototype system was carried out to realistically evaluate its performance. Two types of turbine units were examined; one is an impulse-reaction turbine, and the other is a turbo-alternator. The turbo-alternator was found to be too small in capacity for this system thereby affecting its output significantly. The micro impulse reaction turbine was considered a better option. A typical testing showed that the majority of heat required for the turbine operation came from the boiler (7.65kW), and very little (0.23kW) from the solar collector. The gas consumption was 8.5kW. This operation resulted in an electricity output and domestic hot water generation, which were 1.34kW and 3.66kW respectively. The electrical efficiency was 16% and the thermal efficiency was 43%, resulting in an overall efficiency of 59%. Increasing the number of the collectors used would result in reduced heat output from the boiler. This would help in improving system performance and increasing efficiencies. In this application, number of collectors used would be 4 as the flue gas flow rate would only be sufficient to provide 4 to 5 such collectors for heat recovery. The research resulted in the proposal of another system configuration. The innovative concept is illustrated in Chapter 8, and its key technical issues are discussed.

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Alammar, Ahmed Ali Ghulfus. "Enhancing thermal performance of heat pipe based solar thermal collector." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8207/.

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In this work, a CFD model was developed to simulate the flow and phase-change process inside the Two-Phase Closed Thermosyphon (TPCT). This was carried out to investigate the effect of fill ratio and inclination angle on the thermal performance of the TPCT, and to visualise the phase change characteristics under the influence of the inclination and different fill ratios. Also, the surface wettability in terms of the contact angle was investigated to report their effect on the thermal characteristics of the TPCT and to visualise the phase-change characteristics inside the TPCT for different contact angles using Fluent Ansys. Furthermore, the effect of different parameters on the geyser boiling in the TPCT was investigated experimentally. Consequently, the influence of geyser effect on the TPCT thermal characteristics was examined under the effect of various liquid charges and inclination angles at a broad range of heat inputs. Finally, advanced manufacturing technique using wire Electrical Discharge Machining (EDM) was employed to introduce a surface roughness in the TPCT internal wall, thereby enhancing the thermal performance of the TPCT. This was achieved by comparing its thermal performance with a plain TPCT at two different initial sub-atmospheric pressures (3 and 30 kPa) and different heat loads.

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Endalew, Abebe. "Numerical Modeling and Experimental Validation of Heat Pipe Solar Collector for Water Heating." Thesis, KTH, Tillämpad termodynamik och kylteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-77378.

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This work studies the performance of heat pipe solar collector for water heating. Experimental results are validated using numerical modeling. Homemade heat pipes with distilled water as a working fluid were used for experimental tests. Both natural and forced convective heat pipe condensing mechanisms are studied and their results are compared with conventional natural circulation solar water heating system. Cross flow and parallel flow heat exchanger were tested in forced type heat pipe condensing mechanism. Experimental and numerical results showed good agreement. Heat pipe solar collectors outperformed conventional solar collector because of their efficient heat transport method. Forced convective heat exchanger was found to give higher efficiency compared to natural convective heat pipe condensing system. However, natural convective heat pipe condensing is free from parasitic power and low system weight. It also showed appreciable system efficiency and can be further developed to be used in rural areas where grid electricity is scarce. Cross flow and parallel flow heat exchanger have been tested for forced convective heat pipe condensing mechanism and no appreciable difference was found due to higher fluid velocity in heat exchangers.

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Shafieian, Dastjerdi Abdellah. "A solar‐driven membrane‐based water desalination/purification system." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2020. https://ro.ecu.edu.au/theses/2323.

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Lack of fresh water has turned into one of the major challenges of the world in the present century. Desalination of brackish or seawater has been proven to be one of the best solutions to cope with this global challenge. Among all the desalination methods, Membrane Distillation (MD) is well known as a cost effective and profitable technology for treating saline water. However, higher energy consumption compared to other separation techniques has been reported as MD’s main drawback. That is why the application of solar energy to provide the thermal energy requirement of MD modules has been the focal point of research in this field in recent years. Despite many studies and efforts that have been conducted to date, solar driven membrane based systems have still many undiscussed aspects. Integrating solar energy and membrane technology is not yet a straightforward matter and has many opportunities for technical and economic improvements. Utilizing new solar technologies, their combination with thermal driven membrane modules, and trying to improve thermal and overall efficiency of this integration can be the bedrock of novel researches. Furthermore, most of the previous studies and research activities have been focused on desalination systems, while the proposed systems have been either inefficient or energy intensive, and other sources for improving water quality such as wastewater is completely under-researched. That is why, this study proposed a novel integrated solar membrane-based desalination and wastewater treatment system taking advantage of technologies such as heat pipes, vacuum tubes, and direct contact membrane distillation (DCMD) modules. A theoretical study was considered to firstly investigate the performance and feasibility of the proposed system and secondly to obtain the optimum physical and operational characteristics of both solar and desalination systems. The theoretical analysis was performed by using appropriate energy and exergy equations which were solved in Matlab software. Heat and mass transfer equations along with energy and mass balance equations were considered in this study. A new multi-step theoretical approach was proposed and developed to model the DCMD unit, while the thermal resistance network method was applied in the simulation of the solar system including vacuum glasses, heat pipes, and manifold. Based on the optimum data obtained from the mathematical models, an experimental rig was designed, manufactured, and tested under different climatic and operational conditions. The system was controlled using a central control unit including a control unit, a National Instrument Data Acquisition (NI-DAQ) system, and a power unit. An application program interface (API) was programmed in the LabVIEW 2014 software to record the data at 10- second intervals. Climatic data including solar radiation, ambient temperature, and wind velocity were collected from the weather station located at Edith Cowan University, Joondalup Campus which is located 23 km north of Perth business district. The comparison of the theoretical and experimental results revealed the capability of the developed model to accurately predict the performance of the proposed system. In addition, the optimum characteristics of the system, including the optimum solar collector’s surface area, feed and permeate streams mass flow rates and temperatures, were determined. The results revealed that the application of this nanofluid as the solar working fluid along with implementing a variable mass flow rate technique significantly improved the overall efficiency of the solar system. Sodium Dodecyl BenzeneSulfonate (SDBS) at 0.1 wt.% was the optimum concentration of SDBS for 0.05 wt.% Al2O3/DI water nanofluid exhibiting the highest stability and thermal conductivity enhancement. The results also showed the high dependency of the DCMD module to the physical (e.g., length) and operational (e.g., feed and permeate mass flow rates) parameters, while its performance was independent of salinity. The highest freshwater production rates in hot and cold seasons were observed to be 3.81 and 2.1 L/m2h, respectively. Moreover, the maximum gained output ratios of the system were around 0.79 and 0.58 in hot and cold seasons, respectively. The results also indicated that the gained output ratio and overall efficiency of the system improved upon application of a cooling unit in the permeate flow loop of the system, indicating the effectiveness of the proposed configuration. In addition, the freshwater production increased up to 37% when the system was equipped with a cooling unit. However, the economic feasibility of implementing the cooling unit needs further investigations. Moreover, the proposed system effectively removed the contaminating metals from wastewater by showing the removal percentage of 96, 89, 96, 100, 100, and 94% for Fe, Mn, Cu, Na, K, and Ca, respectively.

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Kužel, Kristián. "Návrh systému řízení a diagnostiky ohřevu vody s využitím solární energie." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230895.

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This thesis deals with problems related to heating of hot service water. It focuses on solar water heating, describes individual types of solar panels and summarizes the existing information about solar water heating. It demonstrates actual problems of solar system solution on a specific example of a two-generation family house, where it analyses possibilities of diagnostics and control of such system. It also deals with suggestions of possible expansion of the current solar system.

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Tiari, Saeed. "EXPERIMENTAL AND NUMERICAL STUDY OF LATENT HEAT THERMAL ENERGY STORAGE SYSTEMS ASSISTED BY HEAT PIPES FOR CONCENTRATED SOLAR POWER APPLICATION." Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/403481.

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Mechanical Engineering
Ph.D.
A desirable feature of concentrated solar power (CSP) with integrated thermal energy storage (TES) unit is to provide electricity in a dispatchable manner during cloud transient and non-daylight hours. Latent heat thermal energy storage (LHTES) offers many advantages such as higher energy storage density, wider range of operating temperature and nearly isothermal heat transfer relative to sensible heat thermal energy storage (SHTES), which is the current standard for trough and tower CSP systems. Despite the advantages mentioned above, LHTES systems performance is often limited by low thermal conductivity of commonly used, low cost phase change materials (PCMs). Research and development of passive heat transfer devices, such as heat pipes (HPs) to enhance the heat transfer in the PCM has received considerable attention. Due to its high effective thermal conductivity, heat pipe can transport large amounts of heat with relatively small temperature difference. The objective of this research is to study the charging and discharging processes of heat pipe-assisted LHTES systems using computational fluid dynamics (CFD) and experimental testing to develop a method for more efficient energy storage system design. The results revealed that the heat pipe network configurations and the quantities of heat pipes integrated in a thermal energy storage system have a profound effect on the thermal response of the system. The optimal placement of heat pipes in the system can significantly enhance the thermal performance. It was also found that the inclusion of natural convection heat transfer in the CFD simulation of the system is necessary to have a realistic prediction of a latent heat thermal storage system performance. In addition, the effects of geometrical features and quantity of fins attached to the HPs have been studied.
Temple University--Theses

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Mahdavi, Mahboobe. "NUMERICAL AND EXPERIMENTAL ANALYSIS OF HEAT PIPES WITH APPLICATION IN CONCENTRATED SOLAR POWER SYSTEMS." Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/400193.

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Mechanical Engineering
Ph.D.
Thermal energy storage systems as an integral part of concentrated solar power plants improve the performance of the system by mitigating the mismatch between the energy supply and the energy demand. Using a phase change material (PCM) to store energy increases the energy density, hence, reduces the size and cost of the system. However, the performance is limited by the low thermal conductivity of the PCM, which decreases the heat transfer rate between the heat source and PCM, which therefore prolongs the melting, or solidification process, and results in overheating the interface wall. To address this issue, heat pipes are embedded in the PCM to enhance the heat transfer from the receiver to the PCM, and from the PCM to the heat sink during charging and discharging processes, respectively. In the current study, the thermal-fluid phenomenon inside a heat pipe was investigated. The heat pipe network is specifically configured to be implemented in a thermal energy storage unit for a concentrated solar power system. The configuration allows for simultaneous power generation and energy storage for later use. The network is composed of a main heat pipe and an array of secondary heat pipes. The primary heat pipe has a disk-shaped evaporator and a disk-shaped condenser, which are connected via an adiabatic section. The secondary heat pipes are attached to the condenser of the primary heat pipe and they are surrounded by PCM. The other side of the condenser is connected to a heat engine and serves as its heat acceptor. The applied thermal energy to the disk-shaped evaporator changes the phase of working fluid in the wick structure from liquid to vapor. The vapor pressure drives it through the adiabatic section to the condenser where the vapor condenses and releases its heat to a heat engine. It should be noted that the condensed working fluid is returned to the evaporator by the capillary forces of the wick. The extra heat is then delivered to the phase change material through the secondary heat pipes. During the discharging process, secondary heat pipes serve as evaporators and transfer the stored energy to the heat engine. Due to the different geometry of the heat pipe network, a new numerical procedure was developed. The model is axisymmetric and accounts for the compressible vapor flow in the vapor chamber as well as heat conduction in the wall and wick regions. Because of the large expansion ratio from the adiabatic section to the primary condenser, the vapor flow leaving the adiabatic pipe section of the primary heat pipe to the disk-shaped condenser behaves similarly to a confined jet impingement. Therefore, the condensation is not uniform over the main condenser. The feature that makes the numerical procedure distinguished from other available techniques is its ability to simulate non-uniform condensation of the working fluid in the condenser section. The vapor jet impingement on the condenser surface along with condensation is modeled by attaching a porous layer adjacent to the condenser wall. This porous layer acts as a wall, lets the vapor flow to impinge on it, and spread out radially while it allows mass transfer through it. The heat rejection via the vapor condensation is estimated from the mass flux by energy balance at the vapor-liquid interface. This method of simulating heat pipe is proposed and developed in the current work for the first time. Laboratory cylindrical and complex heat pipes and an experimental test rig were designed and fabricated. The measured data from cylindrical heat pipe were used to evaluate the accuracy of the numerical results. The effects of the operating conditions of the heat pipe, heat input, and portion of heat transferred to the phase change material, main condenser geometry, primary heat pipe adiabatic radius and its location as well as secondary heat pipe configurations have been investigated on heat pipe performance. The results showed that in the case with a tubular adiabatic section in the center, the complex interaction of convective and viscous forces in the main condenser chamber, caused several recirculation zones to form in this region, which made the performance of the heat pipe convoluted. The recirculation zone shapes and locations affected by the geometrical features and the heat input, play an important role in the condenser temperature distributions. The temperature distributions of the primary condenser and secondary heat pipe highly depend on the secondary heat pipe configurations and main condenser spacing, especially for the cases with higher heat inputs and higher percentages of heat transfer to the PCM via secondary heat pipes. It was found that changing the entrance shape of the primary condenser and the secondary heat pipes as well as the location and quantity of the secondary heat pipes does not diminish the recirculation zone effects. It was also concluded that changing the location of the adiabatic section reduces the jetting effect of the vapor flow and curtails the recirculation zones, leading to higher average temperature in the main condenser and secondary heat pipes. The experimental results of the conventional heat pipe are presented, however the data for the heat pipe network is not included in this dissertation. The results obtained from the experimental analyses revealed that for the transient operation, as the heat input to the system increases and the conditions at the condenser remains constant, the heat pipe operating temperature increases until it reaches another steady state condition. In addition, the effects of the working fluid and the inclination angle were studied on the performance of a heat pipe. The results showed that in gravity-assisted orientations, the inclination angle has negligible effect on the performance of the heat pipe. However, for gravity-opposed orientations, as the inclination angle increases, the temperature difference between the evaporator and condensation increases which results in higher thermal resistance. It was also found that if the heat pipe is under-filled with the working fluid, the capillary limit of the heat pipe decreases dramatically. However, overfilling of the heat pipe with working fluid degrades the heat pipe performance due to interfering with the evaporation-condensation mechanism.
Temple University--Theses

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Pech, Ondřej. "Energetická simulace provozu solárních kolektorů v nízkoenergetickém rodinném domě s teplovzdušným vytápěním." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-228992.

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The thesis deals with energy simulation of a solar energy system in a low-energy family house with warm-air heating. The simulations performed resulted in the assessment of the energy contribution of four solar systems with different types of collectors. The profitability and return of investment for the particular system have been evaluated based on investment costs and the savings gained. The theoretical part includes an introduction to the solar energy field, solar panel systems and the passive house concept. The practical part is devoted to description of the simulated object models as used in the TRNSYS environment, the simulation results evaluation along with the assessment of the economic return on investment. The conclusion recommendations regarding a suitable type and size of the solar panel with respect to the economic criteria chosen are given.

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Abdullahi, Bala. "Development and optimization of heat pipe based compound parabolic collector." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6106/.

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Compound Parabolic Collector (CPC) has numerous advantages such as high optical efficiency and wide applications. This thesis describes experimental and theoretical investigations of the effects of solar radiation available, design and orientation on different configurations of low concentration CPCs for Kano, Nigeria. Two solar radiation models were developed for characterizing solar radiation for regions in the northern hemisphere like Kano. Results showed that tilting the collector to the monthly optimum angle gives the maximum radiation obtainable in each month with highest increase of 28.6 and 24.8% in December and January respectively. For seasonal tilt; the best angles were 27.05° (October to March) and 0° (April to September) while for fixed collector, tilting at 12.05° (latitude) provides the highest performance. Using advanced ray tracing technique, detailed investigations of the effects of acceptance angle, receiver radius, truncation, etc. were carried out on the CPC performance. While with the truncation of 70%, results showed that compound parabolic collector can achieve daily average optical efficiencies of 86.2% and 75.4% for acceptance angles of 60° and 40° respectively. The performance of the thermosyphon (receiver) was investigated both experimentally and numerically. Using an in house solar simulator developed in this work, the performance of the developed CPC fitted with thermosyphon was experimentally investigated. Results showed that the CPC can function well with thermosyphon inclination angle up to 40° where it gives efficiency between 76% and 66%. The outcome of this work shows the potential of using this developed system in Kano environment for cooling applications.

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Zhang, Xingxing. "Investigation of a novel solar photovoltaic/loop-heat-pipe heat pump system." Thesis, University of Hull, 2014. http://hydra.hull.ac.uk/resources/hull:8422.

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With the widespread deployment of solar photovoltaic (PV) and thermal devices imminent, this research aims to resolve some engineering barriers to the existing solar photovoltaic/thermal (PV/T) technologies by incorporating an innovative loop heat pipe (LHP) and a typical heat pump. In addition, a coated aluminium-alloy (Al-alloy) sheet replaces the conventional baseboard for the PV cells to improve heat exportation. As a result, this research has developed a novel solar PV/LHP heat pump system to maximise the electrical output of a PV module and generate an additional amount of heat simultaneously. The overall investigation followed the basic methodology of combined theoretical and experimental analysis, including procedures for a critical literature review, optimal concept design, mathematical derivation, the development of simulation models, prototype fabrication, laboratory-controlled and field testing, simulation model validation and socio-economic analysis. A full range of specialised simulation models was developed to predict the system performance with reasonable accuracy. The proposed LHP device has a maximum heat transfer limit of about 900W. The Al-alloy baseboard improved PV efficiency by nearly 0.26% when compared with a traditional PV baseboard. During the real-time measurement conditions, the mean electrical, thermal and overall energetic/exergetic efficiencies of the PV/LHP module were 9.13%, 39.25% and 48.37%/15.02%, respectively. The basic thermal and advanced system coefficients of performance (COPth/COPPV/T) were almost 5.51 and 8.71, respectively. The test results indicated that this system performed better than conventional solar/air energy systems. The feasibility analysis illustrated that this system could generate a substantial amount of energy in subtropical climatic regions, such as Hong Kong. It is cost effective to operate this system in areas with high energy charging tariffs, such as London and Hong Kong. The research results are expected to configure feasible solutions for future PV/T technologies and develop a new solar-driven heating system. The core technologies may enable a significant reduction in or even elimination of the carbon footprint in the built environment.

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Hess, Stefan. "Low-concentrating, stationary solar thermal collectors for process heat generation." Thesis, De Montfort University, 2014. http://hdl.handle.net/2086/10874.

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The annual gain of stationary solar thermal collectors can be increased by non-focusing reflectors. Such concentrators make use of diffuse irradiance. A collector’s incidence angle modifier for diffuse (diffuse-IAM) accounts for this utilization. The diffuse irra-diance varies over the collector hemisphere, which dynamically influences the diffuse-IAM. This is not considered by state-of-the-art collector models. They simply calculate with one constant IAM value for isotropic diffuse irradiance from sky and ground. This work is based on the development of a stationary, double-covered process heat flat-plate collector with a one-sided, segmented booster reflector (RefleC). This reflector approximates one branch of a compound parabolic concentrator (CPC). Optical meas-urement results of the collector components as well as raytracing results of different variants are given. The thermal and optical characterization of test samples up to 190 °C in an outdoor laboratory as well as the validation of the raytracing are discussed. A collector simulation model with varying diffuse-IAM is described. Therein, ground reflected and sky diffuse irradiance are treated separately. Sky diffuse is weighted with an anisotropic IAM, which is re-calculated in every time step. This is realized by gener-ating an anisotropic sky radiance distribution with the model of Brunger and Hooper, and by weighting the irradiance from distinct sky elements with their raytraced beam-IAM values. According to the simulations, the RefleC booster increases the annual out-put of the double-covered flat-plate in Würzburg, Germany, by 87 % at a constant inlet temperature of 120 °C and by 20 % at 40 °C. Variations of the sky diffuse-IAM of up to 25 % during one day are found. A constant, isotropic diffuse-IAM would have under-valued the gains from the booster by 40 % at 40 °C and by 20 % at 120 °C. The results indicate that the gain of all non-focusing solar collectors is undervalued when constant, isotropic diffuse-IAMs calculated from raytracing or steady-state test data are used. Process heat generation with RefleC is demonstrated in a monitored pilot plant at work-ing temperatures of up to 130 °C. The measured annual system utilization ratio is 35 %. Comparing the gains at all inlet temperatures above 80 °C, the booster increases the an-nual output of the double-covered flat-plates by 78 %. Taking all inlet temperatures, the total annual gains of RefleC are 39 % above that of the flat-plates without reflectors. A qualitative comparison of the new simulation model results to the laboratory results and monitoring data shows good agreement. It is shown that the accuracy of existing collector models can be increased with low effort by calculating separate isotropic IAMs for diffuse sky and ground reflected irradiance. The highest relevance of this work is seen for stationary collectors with very distinctive radiation acceptance.

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Johansson, Helena. "Nocturnal cooling : Study of heat transfer from a flat-plate solar collector." Thesis, Karlstad University, Faculty of Technology and Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-1523.

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This thesis investigates the possibility of using an unglazed flat-plate solar collector as a cooling radiator. The solar collector will be connected to the condenser of a heat pump and used as cooler during nighttime. Daytime the solar collector will be connected to the evaporator of the heat pump and used as heat source. The two widely differing fields of application make special demands on the solar collector. The task is given by the heat pump manufacturer Thermia and the main objective is to find out whether a solar collector should be used as a cooler or not. The performance of the solar collector under varying environmental conditions is investigated using COMSOL Multiphysics 3.3. Only the cooling properties are investigated here. The performance of the solar collector as a heat exchanger is estimated using the effectiveness-NTU method, and the solar collector is found to be a good heat exchanger at low wind speeds. The heat transfer coefficients of the convection and radiation are determined for varying temperature and wind speeds. The convective heat transfer coefficient is lowered by tubes above the absorber plate and for a high convective heat transfer rate the solar collector surface should be smooth. For a high radiative heat transfer rate the surface needs to have a high emissivity. The cooling rate is higher from a warm surface than from a cold and since no temperature change of the heat carrier is necessary the solar collector should be kept at a high temperature. To increase the cooling rate alterations need to be made to the solar collector that makes its heating performance deteriorate. A solar collector that can be used for cooling is not an efficient solar collector.

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Yagoub, Waleed. "Exploitation of solar thermal technologies using a novel heat pipe design." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404043.

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Alwaer, Ayad Almakhzum Mohamed. "A prototype desalination system using solar energy and heat pipe technology." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2455.

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Thesis (DTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016.
The water desalination process needs large quantities of energy, either directly from fossil fuel or electricity from the national grid. However, these sources of energy significantly contribute to problems such as global warming in addition to creating a drain on the economy, due to their high cost. This dissertation is a description of the research undertaken with the aim of producing a water desalination prototype; a novel approach that was designed using state-of-the-art solar water heating equipment, incorporating the technologies of evacuated tubes and heat pipes. During the execution of the project, various modifications to the original commercially-available solar water heating system were attempted, each aimed at increasing the production of pure water. Finally, the system proved capable of producing a reasonable amount of pure water after twelve lengthy indoor experiments conducted in a laboratory in the department of Mechanical Engineering at the Cape Peninsula University of Technology, Bellville Campus, Cape Town, South Africa. Each experiment lasted five days on the basis of seven hours of exposure to an average amount of simulated solar radiation, followed by seventeen hours daily of inactivity and partial cooling down of the system.

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Kleyn, Gysbert. "A comparative study of performance and efficiency of a tube and fin type domestic solar water heat collector." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/7959.

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The main purpose of this research project was to do a comparative study, by identifying a testing methodology for transient conditions, through which to allow the expression of the relative thermal performance of two DSWH collectors in comparison. The study started off by considering literature about Solar Domestic Water Heaters and National Standards-based test methods, most of which were for Steady State testing conditions. Thereafter establishing a testing methodology and setup, identifying factors to be considered. The results were analyzed and conclusions drawn. The hypothesis was to allow the reduction in the complexity of testing equipment and methods, and by doing transient condition testing and still utilizing the Hottel-Whillier-Bliss relationship as a way of expressing efficiency, the hypothesis was proven.

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David, Hertel Julian. "Study on the general applicability of the collector efficiency model to solar process heat collectors." Doctoral thesis, Universitat de les Illes Balears, 2019. http://hdl.handle.net/10803/671483.

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[eng] According to several studies, the installed capacity of solar thermal collectors to provide heat for industrial processes is going to increase significantly during the next decades. The great variety of designs and large range of operating temperatures of solar process collectors make their performance assessment challenging. Although the quasi-dynamic testing procedure has been designed for most types of collectors, it shows limitations or vagueness when dealing with medium-scaled collectors. This thesis analyzes some limitations, focusing mainly on the optical efficiency assessment. A powerful ray-tracing algorithm has been developed for the optical analyses in this thesis. The algorithm was used to carry out a sensitivity analysis of a Fresnel collector to achieve a better understanding of the most influential parameters in ray-tracing simulations. Two observations were made: First, spectral simulations are not relevant for solar thermal applications unless mirror scattering shows a very high dependency on the wavelength. Second, defining the incidence angle dependency of optical materials is crucial to produce accurate results. In the case of biaxial concentrating collectors, the incidence angle modifier factorization model is commonly applied. This model inherently introduces errors by factorizing the underlying non-factorizable functions. The error was characterized for four different collector geometries by comparing factorization with ray-tracing simulations. Results have been presented as a function of geographical latitude. Factorization in the θi-θT -space performed best in nearly all cases. Four different collector geometries were submitted to ray-tracing simulations in order to analyze the thermal dependency of the factorization error. It is shown that the relative error generally increases with higher operating temperatures, but within the economically viable temperature range it stays fairly constant. With higher temperatures the collector gradually stops operating beginning with moments when sun angles are least favorable for factorization.
[cat] Segons diversos estudis, la capacitat instal·lada de captadors solars tèrmics pel subministrament de calor en processos industrials s’incrementarà significativament en els propers anys. La gran diversitat de dissenys i temperatures de treball d’aquest tipus de captador fa difícil l’avaluació dels seus rendiments. Encara que el mètode experimental quasi dinàmic s’ha desenvolupat per la major part de models de captador, segueix tenint limitacions o imprecisions a l’hora d’avaluar captadors específics per calor de procés. Aquesta tesi analitza algunes d’aquestes limitacions, centrant-se principalment en l’avaluació de l’eficiència òptica. Per l’anàlisi òptica, en aquesta tesi s’ha desenvolupat un algoritme avançat de ray-tracing. L’algoritme ha servit per realitzar una anàlisi de sensibilitat d’un captador Fresnel, que ha permès conèixer quins son els paràmetres que tenen una major influència en la qualitat dels resultats obtinguts en les simulacions de ray-tracing. S’ha arribat a dues conclusions: En primer lloc, simulacions espectrals no son rellevants per aplicacions solars tèrmiques, a no ser que la dispersió del mirall depengui significativament de la longitud d’ona. En segon llos és imprescindible especificar al dependència de l’angle d’incidència dels materials òptics per generar resultats acurats. En el cas de captadors concentradors biaxials, s’aplica el model de factorització del modificador d’angle d’incidència. Aquesta factorització te sempre associat un cert error, ja que l’IAM no és en general factoritzable. S’ha caracteritzat l’error per quatre geometries de captadors diferents, comparant el models de factorització amb les simulacions ray-tracing. Els resultats s’han presentat en funció de la latitud geogràfica. La factorització a l’espai θi-θT es la que ofereix més bons resultats en gairebé tots els casos analitzats. Quatre geometries diferents de captador foren analitzades per determinar la dependència amb la temperatura de l’error de factorització. S’ha demostrat que a mesura que s’incrementa la temperatura de treball, s’incrementa l’error relatiu del la factorització, malgrat això, dins del rang de temperatures econòmicament viables, l’error es manté constant. Això és degut a que a mesura s’incrementa la temperatura, es redueixen les hores de treball, i per tant també les hores on el captador treballa sota els angles més desfavorables per la factorització
[spa] Según varios estudios, la capacidad instalada de captadores solares térmicos para proveer calor en procesos industriales se va a incrementar significativamente a lo largo de las próximas décadas. La gran variedad de diseños y temperaturas de este tipo de captadores hace complicada la evaluación de sus rendimientos. Aunque el métdodo experimental quasi-dinámico ha sido diseñado para la mayoría de modelos de captadores, sigue teniendo limitaciones o imprecisiones a la hora de evaluar captadores de mediana escala. Esta tesis analiza algunas de dichas limitaciones, centrándose principalmente en la evaluación de la eficiencia óptica. Para el análisis óptico en esta tesis se ha desarrollado un algoritmo avanzado de raytracing. El algoritmo ha servido para realizar un análisis de sensibilidad de un captador Fresnel, para conseguir con ello un mayor conocimiento de los parámetros más influyentes en las simulaciones ray-tracing. Se ha llegado a dos conclusiones: En primer lugar, simulaciones espectrales no son relevantes para aplicaciones solares térmicas, a no ser que la dispersión del espejo dependa significativamente de la longitud de onda. En segundo lugar, es imprescindible especificar la dependencia del ángulo de incidencia de los materiales ópticos para generar resultados precisos. En el caso de captadores concentradores biaxiales, se aplica el modelo de factorización del ‘incidence angle modifier’. Por defecto, este modelo introduce errores factorizando funciones que no son factorizables. Se ha caracterizado el error para cuatro geometrías de captadores diferentes comparando el modelo de factorización con las simulaciones ray-tracing. Los resultados han sido presentados como función de la latitud geográfica. La factorización en el espacio θi-θT ha demostrado los mejores resultados para casi todos los casos. Cuatro geometrías diferentes fueron sometidas a simulaciones de ray-tracing para analizar la dependencia térmica del mismo error de factorización. Se ha demostrado que a medida que aumenta la temperatura del proceso, aumenta también el error relativo de factorización, sin embargo, dentro del rango económicamente viable de temperaturas, el error se mantiene constante. Esto se debe a que a medida se incrementa la temperatura, el captador deja de operar primero en los momentos de ángulos más desfavorables para la factorización.

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17

Wang, Zhangyuan. "Investigation of a novel façade-based solar loop heat pipe water heating system." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12343/.

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Solar thermal is one of the most cost-effective renewable energy technologies, and solar water heating is one of the most popular solar thermal systems. Based on the considerations on the existing barriers of the solar water heating, this research will propose a novel façade-based solar water heating system employing a unique loop heat pipe (LHP) structure with top-level liquid feeder, which will lead to a façade-integrated, low cost, aesthetically appealing and highly efficient solar system and has considerable potential to provide energy savings and reduce carbon emissions to the environment. The research initially involved the conceptual design of the proposed system. The prefabricated external module could convert the solar energy to heat in the form of low-temperature vapour. The vapour will be transported to indoors through the transport line and condensed within the heat exchanger by releasing the heat to the service water. The heated water will then be stored in the tank for use. An analytical model was developed to investigate six limits to the loop heat pipe’s operation, i.e., capillary, entrainment, viscous, boiling, sonic and filled liquid mass. It was found that mesh-screen wick was able to obtain a higher capillary (governing) limit than sintered-powder. Higher fluid temperature, larger pipe diameter and larger exchanger-to-pipes height difference would lead to a higher capillary limit. Adequate system configuration and operating conditions were suggested as: pipe inner diameter of 16 mm, mesh-screen wick, heat transfer fluid temperature of 60oC and height difference of 1.5 m. This research further developed a computer model to investigate the dynamic performance of the system, taking into account heat balances occurring in different parts of the system, e.g., solar absorber, heat pipes loop, heat exchanger, and tank. Data extracted from two previously published papers were used to compare with the established model of the same setups, and an agreement could be achieved under a reasonable error limit. This research further constructed a prototype system and its associated testing rig at the SRB (Sustainable Research Building) Laboratory, University of Nottingham and conducted testing through measurement of various operational parameters, i.e., heat transfer fluid temperature, tank water temperature, solar efficiency and system COP (Coefficient of Performance). Two types of glass covers, i.e., evacuated tubes and single glazing, were applied to the prototype, and each type was tested on two different days of 8 hours from 09:00:00 to 17:00:00. By comparison of the measurement data with the modelling results, reasonable model accuracy could be achieved in predicting the LHP system performance. The water temperature remained a steady growth trend throughout the day with an increase of 13.5oC for the evacuated tube system and 10.0oC for the single glazing system. The average testing efficiencies of the evacuated tube system were 48.8% and 46.7% for the two cases with the testing COPs of 14.0 and 13.4, respectively. For the single glazing system, the average testing efficiencies were 36.0% and 30.9% for the two cases with the COPs of 10.5 and 8.9, respectively. Experimental results also indicated that the evacuated tube based system was the preferred system compared to the single glazing system. This research finally analysed the annual operational performance, economic and environmental impacts of the optimised evacuated tube system under real weather conditions in Beijing, China by running an approved computer model. It was concluded that the novel system had the potential to be highly-efficient, cost-effective and environmentally-friendly through comparison with a conventional flat-plate solar water heating system.

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18

Deshpande, Dhananjay D. "Computer Modeling Of A Solar Thermal System For Space Heating." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1484142894264319.

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19

Šumić, Mersiha. "Thermal Performance of a Solarus CPC-Thermal Collector." Thesis, Högskolan Dalarna, Energi och miljöteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:du-14526.

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The aim of this master thesis is an investigation of the thermal performance of a thermal compound parabolic concentrating (CPC) collector from Solarus. The collector consists of two troughs with absorbers which are coated with different types of paint with unknown properties. The lower and upper trough of the collector have been tested individually. In order to accomplish the performance of the two collectors, a thorough literature study in the fields of CPC technology, various test methods, test standards for solar thermal collectors as well as the latest articles relating on the subject were carried out. In addition, the set‐up of the thermal test rig was part of the thesis as well. The thermal performance was tested according to the steady state test method as described in the European standard 12975‐2. Furthermore, the thermal performance of a conventional flat plate collector was carried out for verification of the test method. The CPC‐Thermal collector from Solarus was tested in 2013 and the results showed four times higher values of the heat loss coefficient UL (8.4 W/m²K) than what has been reported for a commercial collector from Solarus. This value was assumed to be too large and it was assumed that the large value was a result of the test method used that time. Therefore, another aim was the comparison of the results achieved in this work with the results from the tests performed in 2013. The results of the thermal performance showed that the optical efficiency of the lower trough of the CPC‐T collector is 77±5% and the corresponding heat loss coefficient UL 4.84±0.20 W/m²K. The upper trough achieved an optical efficiency of 75±6 % and a heat loss coefficient UL of 6.45±0.27 W/m²K. The results of the heat loss coefficients are valid for temperature intervals between 20°C and 80°C. The different absorber paintings have a significant impact on the results, the lower trough performs overall better. The results achieved in this thesis show lower heat loss coefficients UL and higher optical efficiencies compared to the results from 2013.

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20

Singh, Harjit. "An experimental study of natural convective heat flow phenomena in concentrating compound parabolic solar collector cavities." Thesis, University of Ulster, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516521.

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21

Mohammed, Hussein A. Mohammed. "Heat Transfer Enhancement in a Parabolic Trough Solar Collector (PTSC) Using Passive Technique and Nanofluids/ Hybrid Nanofluids." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/87667.

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Numerical analysis on a three-dimensional PTSC receiver’s tube model equipped with conical/wavy turbulators was conducted with various types of nanofluids/hybrid nanofluids. The Navier-Stokes equations were solved using FVM coupled with the MCRT method. The flow, thermal and entropy characteristics of the PTSC’s receiver tube were investigated. This research revealed that the coupling of conical/wavy turbulators and hybrid nanofluids effectively augmented the thermal and exergetic efficiencies and reduced the entropy generation rate compared with pure base-fluid.

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22

Abbott, Ashley Burnett. "Analysis of Thermal Energy Collection from Precast Concrete Roof Assemblies." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/10082.

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The development of precast concrete housing systems provides an opportunity to easily and inexpensively incorporate solar energy collection by casting collector tubes into the roof structure. A design is presented for a precast solar water heating system used to aid in meeting the space and domestic water heating loads of a single family residence. A three-dimensional transient collector model is developed to characterize the precast solar collector's performance throughout the day. The model describes the collector as a series of segments in the axial direction connected by a fluid flowing through an embedded tube. Each segment is represented by a two-dimensional solid model with top boundary conditions determined using a traditional flat plate solar collector model for convection and radiation from the collector cover plate. The precast collector is coupled to a series solar assisted heat pump system and used to meet the heating needs of the residence. The performance of the proposed system is compared to the performance of a typical air to air heat pump. The combined collector and heat pump model is solved using Matlab in conjunction with the finite element solver, Femlab. Using the system model, various non-dimensional design and operating parameters were analyzed to determine a set of near optimal design and operating values. The annual performance of the near optimal system was evaluated to determine the energy and cost savings for applications in Atlanta, GA and Chicago, IL. In addition, a life cycle cost study of the system was completed to determine the economic feasibility of the proposed system. The results of the annual study show that capturing solar energy using the precast collector and applying the energy through a solar assisted heat pump can reduce the electricity required for heating by more than 50% in regions with long heating seasons. The life cycle cost analysis shows that the energy savings justifies the increase in initial cost in locations with long heating seasons but that the system is not economically attractive in locations with shorter heating seasons.
Master of Science

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23

Okafor, Izuchukwu Francis. "Influence of Circumferential Spans of Heat Flux Distributions on Secondary Flow, Heat Transfer and Friction Factors for a Linear Focusing Solar Collector Type Absorber Tube." Thesis, University of Pretoria, 2017. http://hdl.handle.net/2263/64173.

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Solar collector absorber tubes play a critical role in converting incident solar heat flux into absorbed thermal energy and transferring it to a heat transfer fluid. In this study a single horizontally orientated absorber tube was investigated numerically in terms of the influence of different circumferential spans of symmetrical and asymmetrical heat flux distributions on buoyancy-driven secondary flow, internal heat transfer and friction factor characteristics. Three types of circumferential heat flux boundaries were considered, namely fully uniform, partial uniform and sinusoidal non-uniform heat flux distributions. Both gravitational symmetry and asymmetry for non-uniform heat flux distributions were investigated to cover symmetry angles in terms of the gravitational field (g) of 0° (symmetrical case), 20°, 30°, 40° and 60°. Different sized stainless steel absorber tubes having a length of 10 m, and inner diameters of 62.7 mm, 52.5 mm, 40.9 mm and 35.1 mm were considered. Three dimensional steady-state simulations were performed for water as working fluid, covering laminar flow Reynolds numbers ranging from 130 to 2200, as well as for turbulent flow Reynolds numbers ranging from 3030 to 202 600. Buoyancy effects, temperature dependent fluid thermal properties, tube-wall heat conduction and the external wall heat losses by convection and radiation were taken into consideration. Average internal heat transfer coefficients, local internal heat transfer coefficients, Richardson numbers and overall friction factors were obtained for different angular spans of incident heat flux, inlet fluid temperatures, heat flux intensities and outer wall thermal conditions Laminar flow results indicated that the angular span, angular position, and intensity of the applied external heat flux all have significant influences on the buoyancy induced mixed convection inside the tube. This resulted in significant variations in the internal heat transfer coefficients and the friction factor which are not well described by classical empirical correlations. Buoyancy induced secondary flow significantly enhanced the internal heat transfer coefficient and significantly increased the friction factor compared to forced convection cases. Higher heat transfer coefficients and friction factors were obtained for non-uniform heat flux distributions compared to uniform heat flux distributions and were found to be dependent on the angle span and position of the heat flux. Higher inlet temperatures resulted in increased Nusselt numbers and lower friction factors, while higher external heat loss resulted in lower Nusselts numbers and lower friction factors. An increase in the asymmetry of the heat flux distribution resulted in a reduction of the Nusselt number and friction factor. Even though turbulent flow cases with a Reynolds number range of approximately 3000 to 9000 were also influenced by buoyancy driven secondary flow, and followed the same parameter trends, it occurred to a lesser extent compared to the laminar flow cases. Turbulent flow cases with Reynolds numbers higher than 9100, exhibited little dependence on secondary flow effects and indicates the suitability of classical fully uniform heat flux heat transfer and friction factor correlations for highly turbulent flow irrespective of the distribution or intensity of the heat flux.
Thesis (PhD)--University of Pretoria, 2017.
Advanced Engineering Centre of Excellence at the University of Pretoria, NRF, TESP, NAC, and SOLAR Hub with the Stellenbosch University, EEDSM Hub and CSIR is highly acknowledged and duly appreciated.
Mechanical and Aeronautical Engineering
PhD
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24

Sari, Ozgur Gokmen. "Exergy Analysis Of A Solar Assisted Absorption Heat Pump For Floor Heating System." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12604765/index.pdf.

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Solar assisted single-stage absorption heat pump (AHP) was used to supply energy to a floor-heating system by using the exergy methods. An existing duplex-house,in Ankara, with a heating load of 25.5 kW was analysed. Heating loads of the spaces in the building were calculated and a floor heating panel was modelled for each space leading to the capacity of the AHP before it was designed. Solar energy was delivered to the evaporator and high temperature heat input delivered to the genarator are met by auxiliary units operating with natural gas.The solar energy gained by flat-plate collectors was circulated through AHP.The anaysis performed according to the storage tank temperature reference value if the water temperature leaving the storage tank exceeds a predetermined value it is directly circulated through the floor heating system. Exergue analysis were carried out with Mathcad program. Exergy analysis showed that irreversibility have an impact on absorption system performance.This study indicated which components in the system need to be improved thermally.A design procedure has been applied to a water-lithium-bromide absorption heat pump cycle and an optimisation procedure that consists of determinig the enthalpy, entropy ,exergy, temperature, mass flow rate in each component and coeficient of performance and exergetic coefficient of performance has been performed and tabulated.

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25

Malan, Daniel Johannes. "Latent heat thermal energy storage for solar water heating using flat heat pipes and aluminum fins as heat transfer enhancers." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/96140.

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Thesis (MEng) -- Stellenbosch University, 2014.
ENGLISH ABSTRACT: Solar energy is a time dependent, high-temperature radiant energy resource. The utility of a solar thermal energy system increases if the hot temperature source is available when it is needed most. This is realized by the thermal storage of the solar energy. Thermal storage gives greater versatility to a solar energy system by decoupling the heat source from the heat sink. A large quantity of energy may be stored during the melting process in a phase change material (PCM) within a small temperature range. This molten PCM can then deliver its absorbed heat at a constant temperature in a heating application. In this study a phase change storage system (PCS) is developed and proposed for a solar water heating application. This PCS system stores more heat per unit mass than would be possible with water across the same temperature range. The heat transfer rate in and out of many PCMs is slow because of the low thermal conductivity of the PCM. However, heat transfer enhancers (HTE), such as heat pipes and fins may be added to enhance heat absorption and heat removal rates. Heat pipes have the inherent capability to transfer heat at high rates across large distances, even where the temperature difference is small. In this thesis a description is given of a PCS system consisting of paraffin wax as the PCM and which uses rectangular heat pipes in conjunction with aluminium fins to enhance heat transfer. The storage design is modular and each module has the characteristic that enhanced heat transfer in and out of the PCM is possible when the module is heated or cooled. It also has the capability to quickly absorb or alternatively to supply heat at a nearly constant temperature during the phase change of the module. A rectangular module was designed and built. The module was then analysed under controlled heat absorption and heat removal cycles. The heat up experiment involved an electrical kettle as the hot temperature source. The heat sink was a mains water heat exchanger. The experimental results were compared to those of a transient numerical model, which calculates theoretically how the module will perform thermally under the given test conditions. The numerical model of the experimental set-up was validated when it was found that the numerical model results resemble the experimental results. The numerical model was then adapted to simulate a novel solar water heater (SWH) with an additional PCS container. The improvement over previous designs is that the additional storage container can be heated to a higher temperature than the allowable geyser temperature. The system also heats up and cools down at a faster rate than would be possible without the HTEs. From the numerical simulation the size and performance of such a system is determined. This numerical analysis indicated that a phase change storage system in a SWH application will increase the hot water delivered by a given solar collector and geyser by increasing the storage capacity and by heating up the geyser overnight for early morning hot water use.
AFRIKKANSE OPSOMMING: Son energie is ‘n tyd afhanklike, hoë temperatuur radiasie energiebron. Die bruikbaarheid van ‘n sontermiese energie sisteem verhoog indien die hoë temperatuur bron beskikbaar is wanneer dit die meeste benodig word. Dit kan verwesenlik word deur die sonenergie termies te stoor. Termiese storing bied groter veelsydigheid aan ‘n sontermiese stelsel deur effektief die hittebron te ontkoppel van die hitte sink. ‘n Groot hoeveelheid energie kan, gedurende die smeltingsproses in ‘n faseveranderingsmateriaal binne ‘n nou temperatuurband gestoor word. Hierdie gesmelte materiaal kan weer op sy beurt in die waterverhittingstoepassing, die geabsorbeerde hitte teen ‘n konstante temperatuur oordra. In hierdie studie word ‘n sonwaterverwarmer stelsel wat aangepas is deur ‘n addisionele latente hittestoor daaraan te heg, voorgestel. Hierdie faseverandering hittestoor kan meer hitte stoor as wat water in dieselfde temperatuur band sou kon. Die hitteoordrag tempo na en van baie van die faseveranderingsmateriale (FVM) is egter as gevolg van die lae termiese geleidingskoëfisient, stadig. Hierdie eienskap kan gelukkig verbeter word deur hittepype en hitteoordrag verhogings materiaal soos vinne by te voeg. Hittepype het die inherente eienskap om hitte teen ‘n hoë tempo oor groot afstande, oor te dra, selfs oor ‘n klein temperatuurverskil. In hierdie tesis word ‘n ondersoek rakende ‘n faseverandering storingsisteem wat bestaan uit paraffien was as die FVM en reghoekige hittepype wat te same met met aluminium finne gebruik word om die hitteoordragtempo te verhoog, beskryf. Die stoorontwerp is modulêr en elke module het die kenmerk van hoë hitteoordrag na en van die FVM. Die module het verder ook die eienskap om vining hitte te absorbeer of hitte af te gee. Dit gebeur teen ‘n konstante temperatuur gedurende die faseverandering van die FVM. Presies so ‘n reghoekige module is ontwerp en gebou en onder beheerde hitte absorbering- en hitte verwyderingsiklusse analiseer. Tydens die verhittings eksperiment is ‘n elektriese ketel van gebruik gemaak wat gedien het as die hoë temperatuur bron. Die hitte sink was ‘n hitteruiler wat kraanwater van ‘n konstante hoogte tenk ontvang het. Die resultate van die volledige toets is met die resultate van tydafhanklike numeriese model vergelyk. Hierdie numeriese model bereken teoreties wat die module se storing verrigting onder gegewe toets omstandighede sal wees. Die numeriese model se resultate het goed vergelyk met die resultate van die eksperimente. Die numeriese model van die module is toe aangepas om ‘n sonwaterverwarmer met addisionele stoortenk wat fase verandering materiaal gebruik, te simuleer. Hierdie ontwerp is anders as vorige ontwerpe in die sin dat hoër temperature as wat die warmwatertoestel kan hanteer, in die faseverandering storingstenk, bereik kan word. Die sisteem kan ook as gevolg van die hitteoordrag verhoging materiaal, vinniger verhit of afkoel en teen ‘n vinniger tempo. Die simulasie van die sonwaterverwarmer met FVM word gebruik om die grootte en verrigting van die sisteem te bepaal. Hierdie numeriese model toon aan dat wanneer ‘n addisionele faseverandering storingstelsel in ‘n sonwaterverwarmer toepassing gebruik word, die warm water wat die verbruiker uit die sisteem kan verkry, kan verhoog. Die rede hiervoor is dat meer hitte gestoor kan word, wat beskikbaar gemaak word aan die warm water tenk.

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26

Saini, Puneet Kumar. "A Preliminary Optimisation and Techno-economic Analysis of Solar Assisted Building Heating System Using Transpired Air Solar Collector and Heat Pump in Sweden." Thesis, Högskolan Dalarna, Energiteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:du-30537.

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This thesis presents an optimisation approach and techno-economic evaluation tool for a system consisting of a transpired solar air collector and air source heat pump in a series arrangement. The thesis also investigates the application of the developed tool for feasibility study of a solar heat pump system for a group of three multi-family houses located in Ludvika, Sweden. Transpired solar air collector is used in combination with an air source heat pump to meet space heating and hot water demand for the defined location. Moreover, the solar pre-heated fresh air is used as a heat source for the heat pump evaporator to improve its coefficient of performance. Solar heat pump systems are extensively studied by numerous researchers, However the analyses about techno-economic feasibility of air source heat pump with transpired air solar collector are still lacking. Therefore, an optimisation tool is developed based on the non-linear programming for coherent operation strategy and variation in collector flow rate. The effect of optimisation along with the techno-economic feasibility for a demo case residential building in Sweden is then preliminary studied based on the defined boundary conditions. The analysis is gradually progressed through several phases of thesis starting from system description and followed by tool methodology and case study. A pre-developed dynamic simulation model is used to obtain the space heating and domestic hot water demand of the building. The electricity expenses of the existing system are evaluated and the results are used as a reference to compare the savings resulting from the installation of transpired solar collectors with gross area of 50 m2. The results are presented as a defined economic indicator such as payback period. The results of the simulation reflect that the installation of 50 m2solar collector area leads to 3 % savings compared to the defined reference case, with a simple payback of 22 years. Moreover, results also indicate that variation of collector flow rate and operation timings are effective strategies to maximise the system savings. The analysis reveals that the optimisation can result in up to 60 % additional savings in comparison to a fixed flow rate case. The developed tool has a potential use for feasibility check at an earlier stage of the installation project, without the need for extensive system simulations. Moreover, the tool overcomes the shortcoming of various available tools such as RETscreen solar air heating project model, which are not designed to evaluate the performance of solar collectors with heat pump systems.

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27

Caglar, Ahmet. "Theoretical And Experimental Performance Analysis Of A Solar Assisted Heat Pump." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12607898/index.pdf.

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In this thesis, performance of a heat pump aided by solar heating system with an evacuated tubular collector has been analyzed theoretically and experimentally. For this purpose, a domestic hot water heating system has been designed, constructed and tested. The evacuated tubular solar collector has been used to achieve higher collector efficiency in winter. The fraction of the solar energy utilized has been measured experimentally and estimated theoretically. Effects of various parameters have been investigated on the performance of the proposed system. A mathematical model was developed to investigate the effects of different environmental, design and operational parameters on the solar heating system. In order to compare the obtained theoretical results with experimental ones, an experimental study has been carried out. For that, a number of experiments have been made at the solar house of the Mechanical Engineering Department of METU. An air-to-air heat pump was integrated with an evacuated tubular solar water heater unit (closed water circulation) and the performance of it has been studied experimentally. As a result of the experimental study, the maximum value of the coefficient of performance of the solar assisted heat pump used in this study was obtained as 4.85. The second law efficiency of the system was between 4.8-27.4 %.

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28

Kamiński, Kazimierz. "Correlation analysis between the design and thermophysical properties of solar collector on the heat transfer effectiveness : PhD thesis summary." Rozprawa doktorska, [s.n.], 2015. http://dlibra.tu.koszalin.pl/Content/1061.

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29

Gil, Camilo. "An Optimal Control Approach for Determiniation of the Heat Loss Coefficient in an ICS Solar Domestic Water Heating System." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2567.

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Water heating in a typical home in the U.S. accounts for a significant portion (between 14% and 25%) of the total home's annual energy consumption. The objective of considerably reducing the home's energy consumption from the utilities calls for the use of onsite renewable energy systems. Integral Collector Storage (ICS) solar domestic water heating systems are an alternative to help meet the hot water energy demands in a household. In order to evaluate the potential benefits and contributions from the ICS system, it is important that the parameter values included in the model used to estimate the system's performance are as accurate as possible. The overall heat loss coefficient (Uloss) in the model plays an important role in the performance prediction methodology of the ICS. This work presents a new and improved methodology to determine Uloss as a function of time in an ICS system using a systematic optimal control theoretic approach. This methodology is based on the derivation of a new nonlinear state space model of the system, and the formulation of a quadratic performance function whose minimization yields estimates of Uloss values that can be used in computer simulations to improve the performance prediction of the ICS system, depending on the desired time of the year and hot water draw profile. Simulation results show that predictions of the system's performance based on these estimates of Uloss are considerably more accurate than the predictions based on current existing methods for estimating Uloss.
Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD

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30

Listén, Lars-Åke, and Harald Wallin. "Luftvärmeväxlare med låg ljudnivå : Även i symbios med solfångare." Thesis, Karlstad University, Division for Engineering Sciences, Physics and Mathematics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-732.

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Rapporten handlar om ett examensarbete omfattande 20 p som är utfört för Thermia AB i Arvika. Uppdragsgivaren ville få fram förslag på möjliga åtgärder som kan minska ljudnivån från en luftvärmeväxlare. För bra helhetsbild av projektet, läs även kapitel: 6.

Värmeväxlaren ingår som en komponent i ett värmepumpssystem, Thermia Aer 5, som använder uteluften som värmekälla. Huvudmålet med projektet blev alltså att undersöka och utvärdera ljudbildningen från värmeväxlaren samt att komma fram till olika förslag på möjliga åtgärder som har potential att sänka ljudnivån. Värmeväxlarens förmåga att uppta energi fick ej heller försämras.

I projektets slutskede tillverkades det också en enkel prototyp på ett av designförslagen där den störande ljudnivån blev lägre. Läs mer om detta längre ner.

Ett delmål som vi själva formulerade, var också att undersöka olika möjligheter att öka värmepumpssystemets totala kapacitet för energiupptagning genom att kombinera systemet med någon form av solfångare. Kombinationen solfångare och luftvärmeväxlare innebär också en lägre ljudnivå eftersom fläkten i värmeväxlaren mer sällan behöver gå på full effekt. I viss mån har även estetiska aspekter på formgivningen beaktats.

Nedan presenteras fyra olika förslag på idéer för att öka luftvärmeväxlarens prestanda:

Av det första förslaget tillverkades en prototyp där luftvärmeväxlarens utblås är riktat uppåt, istället för som nu åt sidan, vilket minskar risken att omgivningen nås av högfrekvent ljud. Högfrekvent ljud sprids nämligen inte så mycket i sidled.

Batteridelen på värmeväxlaren har fått en större area, vilket möjliggör ett minskat volymflöde av luft, utan att den tappar i effekt, jämfört med nuvarande värmeväxlare.

Dessa två åtgärder reducerar det avgivna ljudet med ca10 dB.

En större batteriarea är även positivt ur energisynpunkt då värmefaktorn (COP) ökar på grund av ett minskat antal nödvändiga avfrostningar.

Förslag nummer två inbegriper en solfångarlösning som, tack vare avsaknaden av direktförångning, även går att direktkoppla till köldbäraren (brinen) eller direkt mot värmepumpens ackumulatortank.

Solfångaren täcker hela effektbehovet på sommaren och ger ett tillskott resten av året.

Det tredje förslaget är en s.k. väggplacerad luftsolfångare som förvärmer insugsluften till värmeväxlaren. Den uppenbara fördelen med detta alternativ är den synnerligen enkla konstruktionen vilket gör att kostnaden kan hållas nere, se bild 4.4.4-2.

Det fjärde förslaget, är att låta hela husets tak fungera som en solfångare som bilderna 6-1 visar. Inströmmande luft till värmeväxlaren förvärms av de soluppvärmda takpannorna som kan vara av tegel, betong eller ännu hellre av glas. Dessutom tillvaratas förlustvärme från hustak och ventilation. Detta förslag ger ett mycket gott energiutbyte.

Ytterligare ett intressant sätt att sänka ljudbildningen är att driva fram luften genom värmeväxlaren, helt eller delvis, med hjälp av en hög elektrisk spänning, se kapitel: 6.6.

This report is a candidate degree and the assignment is done in the interest of Thermia AB in Arvika, Sweden. The company wanted proposals of preventive measures aiming to reduce sound emission from a heat exchanger. For a good general impression of the project, see chapter 6. The heat exchanger forms a part of a component in a heat pump system, called Thermia Aer 5, which uses air from outside as a heat source.

The main target of the project was to examine and evaluate sound emission from the heat exchanger and to get different proposals on possible preventive measures in order to lower sound emission. It was not allowed to reduce the heat exchangers ability to collect energy.

In the end of the project a simple prototype was built which took advantage of some of the design proposals. The sound emission from the prototype was reduced.

Another target, formulated by ourselves, was to examine different possibilities to increase the capacity of the heat pump system by combining it with solar collectors. The heat pump system combined with solar collectors also produces reduced sound emission.

Even some aesthetic aspects have been taken into consideration.

Below, four different proposals of ideas are introduced that can increase the performance of the heat exchanger:

The first solution was to direct the air exhaust upwards instead of the tangential exhaust on the present heat exchanger. This makes it more improbable that a high frequency sound wave should reach the surrounding area. Sound with high frequency doesn’t spread so much in a sideways direction. An increase of the battery area makes it possible to lower the air volume flow, because of the increased potential for energy output. These two measures reduced the sound level with a proximal amount of about 10 dB. In addition, an increased exchange battery area increases the heat factor (COP) due to the frost distribution on the battery.

Solution number two include a solar panel that, due to the lack of direct vaporization in the heat pump system, is possible to serial connect direct on the brine or indirectly to the water accumulation tank. The solar panel gives hot water in the summer and an additional energy output the rest of the year.

The third solution is a wall mounted air solar panel which gives the air a higher input temperature to the air heat exchanger. This is a very simple and cost effective solution.

The fourth solution is to let the whole roof of the house act as a solar collector as the pictures 6-1 describes. The sun heats the roofing tile which, in turn, heats streaming air that reaches the heat exchanger. The tile can been made of tiling, concrete - or preferably - transparent glass. Furthermore heat loss from the roof and ventilation is prevented.

Another interesting solution that reduces sound emission is to force air through the exchanger with a high electric voltage field. Further information chapter: 6.6.

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Schön, Gustav. "NUMERICAL MODELLING OF A NOVEL PVT COLLECTOR AT CELL RESOLUTION." Thesis, KTH, Energiteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-212731.

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Solar photovoltaic-thermal (PVT) modules produce heat and power via a heat exchanger attached to the rear of the PV cells. The novel PVT collector in this study is previously untested and therefore its behaviour and thermo-electric performance due to fluid channel configuration and in various climate and operating conditions are unknown. Moreover, the working fluid flowing through the heat exchanger cause a temperature gradient across the module such that a cell near the inlet and a cell near the outlet may have significant temperature differences. PV cells are sensitive to temperature; however the most common way to simulate power output from a PVT is to use the average temperature and ignore the gradient. In this study, a single diode PV model is incorporated into a commercial thermal solver to co-simulate the thermal and electrical output of a novel PVT module design with cell level resolution. The PVT system is modelled in steady state under various wind speeds, inlet temperatures, ambient temperatures, flow rates, irradiation, convection coefficients from coolant and back of the module and two different fluid channel configurations. The results show that of the controllable variables, the inlet temperature has the highest influence of the total power output and that a parallel flow of the fluid channel configuration is preferable. The difference between the cell resolution and the module resolution simulations do not motivate the use of a higher resolution numerical simulation.
En kombinerad solcellspanel och solvärmefångare (PVT) producerar värme och elenergi på samma yta genom att en värmeväxlare upptar värmen från baksidan av solcellspanelen. Den PVT som berörs i denna studien är nyutvecklad och har aldrig tidigare testats, vilket medför att data för hur den beter sig samt dess termo-elektiska prestanda saknas för olika driftförhållanden samt flödeskonfigurationer. Vidare ger mediet som flödar genom värmeväxlaren upphov till en temperaturgradient, vilken kan innebära en påtaglig skillnad i temperatur mellan solcellerna i solcellspanelen vid mediets in- respektive utlopp. Trots solcellers temperaturkänslighet, så sker simulering i allmänhet med avseende på panelens medeltemperatur istället för att hänsyn tas till denna temperaturgradient. I den här studien implementeras en så kallad ”single diode”-modell i en kommersiell numerisk mjukvara termiska beräkningar för att samsimulera termiskt och elektriskt effektuttag ur den nyutvecklade PVT-designen. Designen modelleras statiskt under givna variationer av vindhastighet, inloppstemperatur, omgivande temperatur, flödeshastighet, solinstrålning och konvektionskoefficienter för mediet samt baksidan av modulen. Resultaten visar att kontrollerbara variabler som inloppstemperatur har högst inverkan på den totala effekten samt att en parallell flödeskonfiguration lämpar sig bäst. Studien visar också att skillnaden mellan simulering på cellnivå och modulnivå inte motiverar en numerisk beräkningsmetod med upplösning satt till solcellsnivå.

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32

Redpath, David A. G. "An experimental investigation of thermosyphon heat pipe evacuated tube solar water heaters subjected to a northern maritime climate." Thesis, Ulster University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487166.

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Proprietary evacuated tube solar water heaters (ETSWH) have superior thennal perfonnance in Northern Maritime climates compared with proprietary flat plate solar water heaters (FPSWHs). ETSWHs with heat pipe absorbers are especially suited for use in Northern Maritime climates due to their freeze tolerance and self-regulating heat transfer characteristics and ability to act as thennal diodes. Typically delivering 5-15% more thermal energy per annum, than FPSWHs, this is, however, achieved with higher capital costs. The adoption of thermosyphon fluid circulation compared with forced circulation systems allows the capital cost of solar water heating systems to be reduced, reliability increased and similar levels ofperfonnance to be achieved, for well designed systems. This thesis presents experimental data concerned with thermosyphon heat pipe ETSWHs operated under Northern maritime climatic conditions. It was determined that current proprietary designs of heat pipe ETSWHs originally designed for forced circulation can operate effectively when subjected to a Northern Maritime climate when thennosyphon ' fluid circulation is used instead. Though it was fo~nd that current designs are prone to diurnal reverse fluid flows which 'reduce diurnal efficiency by 11.5% Over the monitoring period from January 2007 to June 2007 it was calculated that predicted and measured solar fractions were within 2.5%. Simple payback periods and costs of the delivered energyare presented and discussed using collected and average meteorological data for the test site located at the Jordanstown campus(fthe University ofUlster. Natural convection within the manifold chamber was investigated through construction of physical models of the manifold chamber under investigation. Reverse thennosyphon fluid flows were recreated under laboratory conditions. Interactions between the pin-fin array within the manifold occurred and it was shown how these affected heat transfer within the manifold cavity. Two dimensional particle imaging velocimetry was used to visualise the thermosyphon fluid flow regime within the manifold chamber. The processed images validated the observations made by previous research that at the pin-fin diameter to spacing ratio used in proprietary heat pipe ETSWHs that locally heat transfer is degraded as the fluid travels through the cavity.

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Cluff, C. Brent, Robert B. Kinney, and F. Eskandani. "Final Report on An Evaluation of Annual Heat Storage of Solar Energy for Arizona Subdivisions Using an Azimuth Tracking Floating Collector." Solar Energy Research Facility, Engineering Experiment Station, University of Arizona (Tucson, AZ), 2013. http://hdl.handle.net/10150/296913.

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34

Farah, Hamad. "Hybrid solar system for heat and electric demands in a simple housing within Sweden and China." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-40596.

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The access to ideal heating and power techniques has always been highly thought after.This is mainly due to the development in housing architecture and the cold nature of certain regions which has led to an increase in popularity of the heating market and modernised heating technologies. The current DH systems make use of CHP plants for thegeneration of power and electricity. These CHP plants for the most part, are powered through biomass and during winter periods the demand for heating is highly increased.The biggest issue with relying on biomass solely is the constant need to burn wasteproducts which not only results in increasing the demand for consuming in more waste,but also results in producing remains (by-products) that cannot be broken down further and hence might require the utilization of land-space (landfills) for their disposal. Solar modules on the other hand, have gained increased popularity in the recent age. This is mainly due their extremely high flexible ability in converting solar irradiance intoelectrical and thermal energies. This study will try to provide a comprehensive study intothe utilization of a hybrid solar system that combines a standard PV module with a flat-plate collector through estimating the energy demands for a simple housing within Sweden and China. This will be the main aim of the study, however the possibilities of integrating this hybrid solar system alongside current DH systems will mostly be discussed in the first sections to proof the possibility of executing such a system. The theoretical work carried out will only include simulations of having just separate,standalone PV and flat-plate collector modules. However, designing a hybrid solar and DH system will not be the major focus of this study. The results at the end of the report,concluded that the electrical production for the Swedish case were noticeably higher thanthat of the Chinese case in spite of maintaining the same load values through both cases and higher solar irradiation for the Chinese case. Due to PVsyst simulation constraints,the results show that the investment cost of the Swedish PV (electrical component) module was about 3.6 times greater than that of the Chinese which could possibly mean that the Swedish case has a bigger PV module area than the Chinese case in order to meetel ectricity demand monthly. However, when it came to the thermal energy production, it was possible to assume different collectors cases and hence an area of 7m2 was chosen for the Swedish perspective while an area of 4m2 has been considered for the Chinese case. The thermal useful energy values where then compared with heating demands for both of the cases. Finally, the thesis concluded that there was no requirement for having an integrated DH network within the standalone houses, having small electricity and heat demand and hence, it might be more beneficial to have an integrated DH and solar system within more densely populated housing areas.
Efterfrågan på tillgången till idealisk uppvärmning och effektiva tekniker har alltid varithög. Detta beror främst på utvecklingen inom arkitektur och den kalla naturen i vissaregioner som har lett till en ökad popularitet av värmemarknaden och moderniseradevärmeteknologiert. De nuvarande fjärrvärme-systemen använder kraftvärmeverk förproduktion av kraft och elektricitet. Dessa kraftvärmeanläggningar drivs till stor delgenom biomassa och under vinterperioderna ökar efterfrågan på uppvärmning mycket.Det största problemet med att förlita sig på biomassa enbart är det ständiga behovet avatt bränna avfallsprodukter som inte bara resulterar i att öka efterfrågan på konsumtionav fler avfallsprodukter utan också resulterar i att producera rester (biprodukter) sominte kan brytas ned ytterligare och därmed kan kräva användning av markutrymme fördeponering. solar-moduler å andra sidan har ökat popularitet under de senaste åren.Detta beror främst på deras extremt höga flexibla förmåga att konvertera solbestrålningtill elektrisk och termisk energi. Denna studie kommer att försöka tillhandahålla enomfattande studie av användningen av ett hybridsolsystem som kombinerar en standardPV-modul med en flatplate collector för att simulera en solar-modul samt caselera enfristående version genom att uppskatta energikraven för en enkel bostad i Sverige ochKina. Detta kommer att vara huvudmålet med studien, men möjligheterna att integreradetta hybrida solsystem tillsammans med nuvarande DH-system kommer mestadels attdiskuteras i de första avsnitten för att bevisa möjligheten att utföra ett sådant system. Detteoretiska arbetet som utförs kommer endast att innehålla simuleringar av att bara ha enfristående PV- och flatplate collector module, men att utforma ett hybrid sol- och DHsystemkommer inte att vara huvudfokus för denna studie. Resultaten i slutet avrapporten drog överraskande slutsatsen att den elektriska produktionen för den svenskacaselen var märkbart högre än den för den kinesiska caselen trots att de båda caselernabibehöll samma belastningsvärden och högre solbestrålning för den kinesiska caselen.Detta kan förklaras av skillnaden i modulpriser vid simulering genom PVsyst därinvesteringskostnaden för den svenska PV-modulen (elektrisk komponent) var ungefär3,6 gånger större än den för kinesiska, vilket innebär att PVsyst antar ett störremodulområde för svensk modul och därmed mer energiproduktion. Men när det kom tillvärmeenergiproduktionen, var det möjligt att anta olika samlarfall och följaktligen valdesett område på 7m2 för det svenska perspektivet medan ett område på 4m2 har beaktatsför den kinesiska och värmevärden för användbar energi där jämfördes sedan med dekrav som krävs för uppvärmning i båda fallen. Slutligen drog avhandlingen slutsatsen attdet inte fanns något krav på att ha ett integrerat DH-nätverk i de fristående husen ochdärför kan det vara mer fördelaktigt att ha ett integrerat DH och solsystem i tätarebebyggda bostadsområden.

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Popov, Petr. "Návrh řízení průtoku teplovodním výměníkem solárního systému." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228300.

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Problems of heating of supply water by solar energy are described in this paper. In term of these works was designed and realized attenuate prototype of solar system. There was realized measurements of the temperatures on this prototype and on the basis of these measurements was identified system parameters. Creation of compute simulation of solar system was the further step of this paper. The compute simulation was verified on the basis of comparing of final temperatures with experimental prototype. The design of control algorithm of flow of liquid through the solar system to reach the maximum effect of system is programme of this paper. Simulations of control algorithms are make in environment of MATLAB SIMULINK.

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Гаврилишин, Ростислав Іванович, and Rostyslav Havrylyshyn. "Енергоефективність акумулювання сонячної енергії в приватному секторі." Master's thesis, ТНТУ імені Івана Пулюя, 2019. http://elartu.tntu.edu.ua/handle/lib/29912.

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Дипломна робота присвячена розрахунку та оцінці енергоефективності акумулювання сонячної енергії в приватному секторі. У ході роботи проведено аналіз ефективності складових систем. Таких як сонячний колектор, вакуумний трубчастий колектор, теплоакумулятор. Проаналізовано вплив погоди на ефективність таких систем по метеорологічним даним протягом року. Розраховано кількість генерованої електроенергії та розподілено по місяцях для зручності подальшого аналізу. Відповідно до розрахунку кількості генерованої електроенергії обчислено економічну ефективність панелей у цілому. Результатом роботи є готовий аналіз доцільності та можливості встановлення сонячних панелей на території Тернопільської області.
The thesis is devoted to the calculation and assessment of energy efficiency of solar energy storage in the private sector. In the course of the work, the efficiency of the component systems is analyzed. Such as solar collector, vacuum tubular collector, heat accumulator. The influence of weather on the performance of such systems is analyzed. The amount of electricity generated has been calculated and distributed by months for ease of further analysis. The result of the work is a finished analysis of the feasibility and possibility of installing solar panels in the Ternopil region.
ПЕРЕЛІК УМОВНИХ ПОЗНАЧЕНЬ...6 ВСТУП...7 1. ЛІТЕРАТУРНИЙ ОГЛЯД 1.1. Перспективи сонячної енергетики...10 1.2. Розвиток фотовольтаїчної індустрії...12 1.3.Типи сонячних колекторів...15 1.4. Накопичувачі енергії...18 1.5. Вибір акумулятора для системи накопичення електричної енергії...20 1.6. Енергонезалежний будинок...23 1.7. Висновки...25 2. ОСНОВНА ЧАСТИНА 2.1. Ефективність перетворення сонячної енергії у електричну...26 2.2. Ефективність перетворення сонячної енергії у теплову...29 2.3. Втрати при акумулюванні електричної енергії...33 2.4. Втрати при акумулюванні теплової енергії...37 2.5. Використання акумульованої енергії. Втрати при її конвертуванні...41 2.6. Розрахунок втрат будинку...46 2.7. Висновки...50 3. СПЕЦІАЛЬНА ЧАСТИНА 3.1. Оцінка погодних умов у Тернополі...51 3.2. Кількість енергії, що потрапляє на поверхню від Сонця...52 3.3. Кількість генерованої електроенергії з сонячного випромінювання...54 3.4. Кількість генерованого тепла з сонячного випромінювання...55 3.5. Потреби у електроенергії та теплі середньостатистичного приватного будинку...56 3.6. Висновки...60 4. ОБҐРУНТУВАННЯ ЕКОНОМІЧНОЇ ЕФЕКТИВНОСТІ 4.1. Економічна ефективність і окупність сонячної станції...61 4.2. Розрахунок річної економії коштів згідно теоретично розрахованій кількості річної генерації тепла сонячними колекторами...62 4.3. Розрахунок річної економії коштів згідно теоретично розрахованій кількості річної генерації електроенергії сонячними панелями...63 4.4. Розрахунок річних витрат пов’язаних з експлуатацією сонячних колекторів та панелей...64 4.5. Висновки...65 5. ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ 5.1 Охорона праці...66 5.1.1 Актуальність проблеми електробезпеки...66 5.1.2 Система попередження пожеж...67 5.2 Безпека в надзвичайних ситуаціях...71 5.2.1 Організація цивільного захисту на об’єктах енергетики...71 5.2.2 Захист обладнання для акумулювання сонячної енергії в приватному секторі, від ушкоджень що викликані електромагнітним імпульсом (ЕМІ) ядерних вибухів...73 6. ЕКОЛОГІЯ 6.1 Енергетичні ресурси навколишнього середовища...77 6.2 Нетрадиційні й відновлювані джерела енергії...80 ВИСНОВКИ...84 СПИСОК ВИКОРИСТАНИХ ДЖЕРЕЛ...85

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Oliveira, Santiago del Rio. "Otimização exergetica de um sistema coletor-armazenador de calor latente." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263492.

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Orientadores: Luiz Fernando Milanez, Alcides Padilha
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-08-12T14:21:28Z (GMT). No. of bitstreams: 1 Oliveira_SantiagodelRio_D.pdf: 2035815 bytes, checksum: 7d72e5c223058fb0ce3675f4600214f5 (MD5) Previous issue date: 2008
Resumo: O objetivo desse trabalho é fazer uma otimização exergética de um sistema térmico de energia solar. Esse sistema é composto por um coletor solar e por um tanque armazenador de água retangular que contém material de mudança de fase distribuído em um conjunto de barras. Esse estudo leva em consideração ambas transferências de calor por condução e convecção para a água no coletor solar, e também o processo de mudança de fase para o PCM no armazenador térmico. Assim, no coletor solar são determinadas a temperatura ótima de saída e vazão mássica ótima da água em função das condições de radiação solar. Além disso, para o tanque armazenador, são determinadas a temperatura ótima de fusão do PCM e o máximo trabalho que pode ser obtido levando em consideração o processo de mudança de fase. O processo de fusão do PCM é analisado por meio de uma solução analítica aproximada. Finalmente, foram feitas uma análise energética e exergética de cada componente do sistema bem como de todo o sistema e foram calculadas eficiências de primeira e segunda lei da termodinâmica. Resultados numéricos de um estudo de caso são apresentados e discutidos.
Abstract: This work deals with the exergetic optimization of a solar thermal energy system. This consists of a solar collector and a rectangular water storage tank that contains a phase change material distributed in an assembly of slabs. The study takes into account both conduction and convection heat transfer modes for water in the solar collector, and also the phase change process for the PCM in the storage tank. Thus, in the solar collector, optimal output temperature and optimal mass flow rate are determined as a function of solar radiation conditions. Moreover, for the storage tank, optimal melting temperature and the maximum power output taking into account the phase change process are determined. The melting process in a PCM is analyzed by means of an approximated analytical solution. Finally, energetic and exergetic analysis were done for each system component and for the overall system, and efficiencies of first and second law of thermodynamics were calculated. Results of a numerical case study are presented and discussed.
Doutorado
Termica e Fluidos
Doutor em Engenharia Mecânica

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Cseri, Peter. "Systém řízení slunečních kolektorů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-218907.

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In the first part of my thesis, I was studying materials about using solar energy. Then I write search about all components that are necessary to be used in solar systems. After that I designed the structure of solar system used for heating the hot water for a family house about 4 persons. For this system I designed a regulator and one layer circuit board using Eagle layout editor 4.12r2, which I assembled and tested. This followed creating and debugging program for microprocessor that controls the whole device. This functional regulator for solar collectors connected in a box together with the necessary electronic components is my final product of this project.

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Shah, Hassim. "Integration of solar thermal collectors in the dairy industry: A techno-economic assessment : A case study of Dubai." Thesis, Uppsala universitet, Institutionen för elektroteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-446212.

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A predominant amount of energy needed in the industrial sector is in the form of heat. A significant number of industries in the world still relies on fossil fuels for meeting their heat requirements. A transition to renewable energy for heating needs is at a snail's pace due to fossil fuel lock-in, cost superiority of conventional fuels, and less government support for renewable technology for thermal requirements. The dairy industry is one of the sectors that need heat energy for its production process. This study deals with a techno-economic analysis on the integration of parabolic trough collectors in the dairy industry. The thesis finds the barriers for solar-thermal collectors to evolve in the dairy sector and the viewpoint of the dairy industry towards the acceptance of solar thermal for meeting their thermal needs. From a literature review, it is observed that the need for dairy product will increase in the coming year. To meet the demand, the production process has to be increased. For sustainable production, companies have to rely on environment-friendly energy sources to meet the thermal demand. In the thesis work, it was also found that for several solar fractions, the LevelizedCost of Heat (LCoH) of solar-assisted heating system is less than the LCoH of the fossil-fueled conventional boiler. Therefore, it is economically viable to integrate solar thermal collectors in the dairy industry. The project also compares the LCoHof solar-assisted heating system when solar integration is done at a) feed water heating, b) direct steam generation, and c) process integration. The effect of integration point on the solar fraction, LCoH, and carbon mitigation potential is presented for a real case dairy unit in Dubai. The simulations are performed using a dynamic simulation tool. Results show that minimum LCoH and solar fraction are achieved for process integration. The process integration results in up to 90 % of the solar fraction. Through process integration, the LCoH of the conventional boiler can be reduced by 60%.

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Osório, Tiago Vaz Pato. "Linear solar concentrators: new testing tools and facilities, application to novel CPC-type collectors for industrial process heat." Doctoral thesis, Universidade de Évora, 2019. http://hdl.handle.net/10174/25797.

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Solar energy can be converted into heat in small-scale or large-scale systems that work at low, medium or high temperatures. Presently, a major growth is being observed in large-scale systems for district heating and industrial process heat. Linear concentrators have a well-recognized role in this context and new configurations and solutions are in demand. These must be within the scope of product certification schemes, which rely on international testing standards. This thesis discusses the limitations of the current standards for linear concentrators and presents the design and construction of the Solar Concentrators Testing Platform at the University of Évora. The use of ray-tracing simulation tools to complement and extend the experimental results is also explored. This thesis goes on to present the development of new collector solutions for medium temperature applications (100–250 °C). The principles of non-imaging optics were used in the design of low-concentration (1 to 5) linear CPC-type solar reflectors with evacuated receivers that can generate high-performance, flexibly mounted and affordable solutions. Two collector concepts were investigated. The first is a stationary CPC-type collector with acceptance of 90°. The manufacturing process was considered by analysing different virtual absorber geometries. A prototype was built and tested. The second concept is a quasi-stationary CPC-type collector that only requires a few changes in its position along the year and does not need a sun-tracking system. As the search for the optimal collector design for a specific installation is complex, a thermo-economic optimization method was developed. Two prototypes were built and tested in a collaboration with the company MCG mind for metal. This collector, which is now at its final development stage, will be installed at an industrial facility - KEMET Electronics - in Évora, Portugal; Sumário: Concentradores solares lineares: novas ferramentas e infraestruturas de ensaio, aplicação a novos colectores do tipo CPC para calor de processo industrial A energia solar pode ser convertida em calor em sistemas de pequena ou grande escala, que funcionam a baixas, médias ou altas temperaturas. Actualmente, regista-se um grande crescimento na instalação de sistemas de grande escala para redes de calor e calor de processo industrial. Os concentradores lineares têm um papel reconhecido neste contexto e novas configurações e soluções estão em desenvolvimento. Estas devem integrar-se do âmbito dos esquemas de certificação, que se baseiam em normas de ensaio internacionais. Esta tese discute as limitações das normas actuais no ensaio de concentradores lineares e apresenta o projecto e a construção da Plataforma de Ensaio de Concentradores Solares na Universidade de Évora. O uso de ferramentas de simulação, através de técnicas de traçado de raios, é explorado com o fim de complementar e ampliar os resultados experimentais. A tese prossegue apresentando o desenvolvimento de novas soluções de colectores para aplicações a média temperatura (100–250 °C). Os princípios da óptica não reprodutora de imagem foram usados no desenho de refletores solares lineares do tipo CPC, de baixa concentração (1 a 5), com receptores evacuados que podem originar soluções com bom desempenho, montagem flexível e custos acessíveis. Dois conceitos de coletores foram investigados. O primeiro é um coletor estacionário do tipo CPC com aceitação de 90 graus. O processo de fabricação foi considerado através da análise de diferentes geometrias dos absorsores virtuais. Um protótipo foi construído e ensaiado. O segundo conceito é um coletor quasi-estacionário do tipo CPC, que requer apenas algumas mudanças na sua posição ao longo do ano, dispensando sistemas de seguimento solar. Devido à complexidade na definição do design ideal do coletor para uma instalação específica, foi desenvolvido um método de otimização termoeconómica. Foram construidos e ensaiados dois protótipos em colaboração com a empresa MCG mind for metal. Este colector, que se encontra actualmente no seu estágio final de desenvolvimento, será instalado num edifício industrial - a KEMET Electronics - em Évora, Portugal.

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Пономарчук, І. А., Р. О. Ворончук, and В. В. Багрій. "Аналіз ефективності використання комбінованих систем теплопостачання багатоповерхової житлової будівлі." Thesis, ВНТУ, 2018. http://ir.lib.vntu.edu.ua//handle/123456789/24333.

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В даній доповіді буде показано комбіноване використання сонячних колекторів та геотермальних теплових насосів і описана їх ефективність.
This report will show the combined use of solar collectors and geothermal heat pumps and describe their effectiveness

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Šmardová, Eva. "Energetický posudek solární soustavy." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372048.

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The first part of diploma thesis describes how to measure the parameters of solar thermal collector and solar thermal system. The computational part analyzes heat consumption in the evaluated building and describes design of the solar thermal system for domestic hot water. Last part focuses on the energy assessment of the designed solar system above and evaluation of the solar system, which is located at the Faculty of Civil Engineering in BUT.

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Ebrahim, Mila. "Performance Evaluation of a Photovoltaic/Thermal (PVT) Collector with Numerical Modelling." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302122.

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In Photovoltaic/Thermal (PVT) technology, both PV and solar thermal technology are integrated in the same module for simultaneous electricity and heat production. Research has shown that there are multiple benefits from integrating PVT collectors with a ground source heat pump (GSHP) system, since it allows for seasonal storage of thermal energy over the year. Furthermore, it leads to reduced operating temperatures for the PVT collectors which can increase efficiency and lifetime. The aim of this study is to present the electric and thermal performance of a PVT collector developed by Solhybrid i Småland AB, for different environmental and fluid inlet conditions that can occur when PVT collectors are connected to a GSHP system. Furthermore, the performance of this PVT design is evaluated with ASHRAE (Standard 93-2003), to allow for comparison with other PVT collector designs, with values on the overall heat loss coefficient (UL) and heat removal factor (FR). The modelling tool used for the study is the software COMSOL Multiphysics, which uses the finite element method to solve the partial differential equations in heat transfer and fluid flow problems. Based on the performance curves, the thermal and electrical efficiency of the collector is approximately 48.0-53.4% and 19.0-19.2% respectively at a reduced temperature of zero and irradiance levels of 800-1000 W/m2 for the mass flow rate of 0.026 kg/sm2 which was determined as most suitable to increase thermal performance. Furthermore, these results resulted in a heat removal factor (FR) and overall heat loss coefficient (UL) of 0.56-0.62 and 53.4-53.5 W/m2 K respectively. The results on the performance of the PVT collector in different weather conditions shows that the inlet water temperature can significantly affect operating time and the amount of thermal energy that can be extracted during the year, especially if the collector operates in a colder climate like Sweden. To assess the accuracy of the created model, future work includes experimental testing of the studied PVT collector.
En panel med kombinerad teknik av både solceller och termisk solfångare (PVT) kan producera både elektricitet och värme samtidigt. Forskning har visat att det kan finnas flera fördelar med att integrera PVT-paneler med ett bergvärmesystem, eftersom det mjliggör lagring av termisk energi över året. Dessutom leder ett sådant system till lägre drifttemperaturer som kan öka PVT-panelens effektivitet och livslängd. Syftet med studien är att presentera den elektriska och termiska prestandan av en PVT-panel utvecklat av Solhybrid i Småland AB för olika driftförhållanden som kan uppstå på grund av olika väderförhållanden och inlopps-temperaturer när panelerna är kopplade till ett bergvärmesystem. Vidare utvärderas prestandan för denna panel med ASHRAEmetoden (standard 93-2003), för att möjliggöra jämförelse med andra PVT-paneler. Modelleringsverktyget som använts i studien är mjukvaran COMSOL Multiphysics, som använder finita elementmetoden för att lösa partiella differentialekvationer i värmeöverförings-och flödesproblem. Baserat på prestandakurvorna som presenteras i resultatet, är den termiska och elektriska verkningsgraden approximativt 48.0-53.4% respektive 19.0-19.2% för en reducerad temperatur med värdet noll, en solstrålning mellan 800-1000 W/m2, för en massflödeshastighet på 0.026 kg/sm2 som beslutades som den mest lämpliga för att öka den termiska prestandan. Resultaten resulterade i en värmeavledningsfaktor (FR) och total värmeförlustkoefficient (UL) på 0.56-0.62 respektive 53.4-53.5 W/m2 K. Resultaten på PVT-panelens prestanda under olika väderförhållanden visar att vattnets inloppstemperatur kan påverka drifttiden och mängden termisk energi som kan extraheras under året avsevärt, speciellt i nordiskt klimat. För att bedöma korrektheten i resultaten och den skapade modellen rekommenderas experimentell testning av den studerade PVT-panelen.

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Lainka, Pavel. "Využití termických panelů pro zvýšení účinnosti chladiciho okruhu TČ." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254311.

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This thesis evaluates the connection of solar collectors with heat pump. The work demonstrates meaningful use of solar collector to increase cooling efficiency of the heat pump. Introduction The work introduces the reader to the issue and describes basic principles of the two main sources of energy used in the system - the heat pump and solar system. Next session is dedicated to analysis and evaluation of the data that was measured during system operation. A comparison of measured COP of the heat pump at two different modes of operation was used for the evaluation - with the help of the solar system and without using the solar system.

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Грушицький, Олександр Вікторович, and Oleksandr Hrushytskyi. "Теплопродуктивність системи сонячного гарячого водопостачання." Master's thesis, ТНТУ імені Івана Пулюя, 2019. http://elartu.tntu.edu.ua/handle/lib/30171.

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Вcтaнoвленo, щo дo 90 % вciх теплoвих втpaт coнячнoгo кoлектopa вiдбувaютьcя чеpез пpoзopу iзoляцiю, тoму пpи пpoектувaннi coнячних кoлектopiв знaчнa увaгa мaє бути пpидiленa вибopу пpoзopoї iзoляцiї з виcoким oпopoм теплoпеpедaчi. Тoму зaпpoпoнoвaнo зacтocувaння вaкуумних cклoпaкетiв як бiльш ефективних в пopiвняннi з oдинapним i пoдвiйним cклiнням пpoзopoї iзoляцiї в плocких coнячних кoлектopaх i coнячних кoлектopaх з вiдбивaчaми. У пopiвняннi з oдинapним i пoдвiйним cклiнням вaкуумнi cклoпaкети мaють бiльш виcoкий oпip теплoпеpедaчi. Пpи цьoму тoвщинa ВCП не нaбaгaтo бiльше oдинapнoгo cклiння - близькo 6 мм. Зaпpoпoнoвaнo зaхoди для удocкoнaлення метoдики визнaчення теплoтехнiчних хapaктеpиcтик coнячних кoлектopiв з вaкуумoвaних cклoпaкетaми, щo включaє poзpaхункoвo-екcпеpиментaльний метoд визнaчення тиcку вcеpединi вaкуумнoгo зaзopу. Пpoведенo poзpaхунoк oптимaльних хapaктеpиcтик вaкуумoвaнoгo cклoпaкету. З якoгo вихoдить, щo для тoгo щoб oпip теплoпеpедaчi вaкуумoвaнoгo cклoпaкету пеpевищувaлo oпip теплoпеpедaчi oдинapнoгo i пoдвiйнoгo зacклень з cелективним пoкpиттям, неoбхiднo нaнеcення oднoгo cелективнoгo пoкpиття з випpoмiнювaльнoю здaтнicтю 0,1 нa внутpiшню пoвеpхню cклa вaкуумoвaнoгo cклoпaкету i cтвopення вaкууму не нижче 10-3 мм pт. тт. Пpи цих знaченнях oпip теплoпеpедaчi вaкуумoвaнoгo cклoпaкету cклaде 0,77 (м2·К)/Вт, щo бiльше нiж у oднoгo cклa з cелективним пoкpиттям в 3 paзи, нiж у пoдвiйнoгo cклa з cелективним пoкpиттям в 2 paзи.
It is established that up to 90% of all thermal losses of a solar collector occur through transparent insulation, so when designing solar collectors considerable attention should be paid to the choice of transparent insulation with high heat transfer resistance. Therefore, it is proposed to use vacuum windows as more effective than single and double glazing transparent insulation in flat solar collectors and solar collectors with reflectors. Vacuum windows have higher heat transfer resistance than single and double glazing. However, the thickness of the VSP is not much more than a single glazing - about 6 mm. Measures are proposed to improve the method of determining the thermal characteristics of solar collectors with evacuated double-glazed windows, which includes a calculation and experimental method for determining the pressure inside the vacuum gap. The optimal characteristics of the evacuated glass unit have been calculated. From which it follows that in order for the heat transfer resistance of the evacuated glass unit to exceed the resistance of the heat transfer of single and double glazing with selective coating, it is necessary to apply one selective coating with a radiating capacity of 0.1 to the inner surface of the glass vacuum-forming glass 3 mm . vols. At these values, the heat transfer resistance of the evacuated glass unit will be 0.77 (m2 • K) / W, which is more than one glass with a selective coating 3 times than a double glass with a selective coating 2 times.
ПЕРЕЛІК ПОЗНАЧЕНЬ ТА СКОРОЧЕНЬ ВСТУП РОЗДІЛ І. ЛІТЕРАТУРНИЙ ОГЛЯД...16 1.1. Актуальність та перспективи сонячної теплоенергетики в Україні...16 1.2. Нагрівання води сонячним випромінюванням...20 1.3. Типи сонячних колекторів...22 1.4. Плоскі сонячні колектори...22 1.4.1. Рідинні сонячні колектори...22 1.4.2. Повітряні сонячні колектори...26 1.5. Сонячні колектори з вакуумною трубкою...29 1.6. Сонячні колектори з відбивачам...30 1.7. Типи прозорої ізоляції для сонячних колекторів...34 1.7.1. Одинарне, подвійне скління...34 1.7.2. Скло з селективними покриттями...35 1.7.3. Прозора ізоляція з полімерних матеріалів...36 1.8. Вакуумні склопакети...39 1.8.1. Конструкція вакуумних склопакетів...39 1.8.2. Вплив товщини скла на коефіцієнт теплопередачі ВСП...40 1.8.3. Вплив селективного покриття на ефективність ВСП...41 1.9. Висновки до розділу...42 РОЗДІЛ 2. ОСНОВНА ЧАСТИНА...44 2.1. Методика розрахунку сонячного колектора з вакуумованим склопакетом...44 2.1.1. Постановка завдання...44 2.1.2. Тепловий баланс сонячного колектора з вакуумованим склопакетом...45 2.1.3. Залежність коефіцієнта теплопровідності розрідженого газу від тиску в вакуумному зазорі вакуумованого склопакету...53 2.2. Розрахунок характеристик вакуумованих склопакетів, які забезпечують підвищення енергоефективності сонячних колекторів...58 2.3. Розрахунок сонячних колекторів з відбивачами...66 2.4. Графоаналітичний метод розрахунку оптичного ККД системи «концентратор-приймач»...68 2.5. Метод розрахунку коефіцієнта концентрації по балансу променистих потоків...74 2.6. Розрахунок енергетичних характеристик сонячного колектора з ©-подібними відбивачами...79 2.6.1. Геометричні параметри ©-подібного відбивача...79 2.6.2. Розрахунок оптичного ККД і коефіцієнта концентрації теплового модуля з ©-подібними відбивачами...80 2.7. Визначення ексергії сонячного колектора з ©-подібними відбивачами...82 2.8. Висновки до розділу...84 РОЗДІЛ 3. СПЕЦІАЛЬНА ЧАСТИНА...86 3.1. Використання редактора формул у MS Word для виконання роботи магістра...86 3.2. Команди меню редактора формул...89 РОЗДІЛ 4. ОБГРУНТУВАННЯ ЕКОНОМІЧНОЇ ЕФЕКТИВНОСТІ...93 4.1. Обґрунтування використання сонячних колекторів...93 4.2. Техніко-економічне обґрунтування системи опалювання і нагріву води на базі геліоколектора...97 4.3. Висновки до розділу...99 РОЗДІЛ 5. ОХОРОНА ПРАЦІ ТА БЕЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ...100 5.1. Основні вимоги безпеки до улаштування та експлуатації технологічного обладнання...100 5.2. Сигнально-попереджувальні пристрої і фарбування...102 5.3. Особливості проведення рятувальних та інших невідкладних робіт при ліквідації наслідків великих виробничих аварій і катастроф...103 РОЗДІЛ 6. ЕКОЛОГІЯ...106 6.1. Класифікація забруднень довкілля...106 6.2. Матеріальні та енергетичні забруднення...108 6.3. Висновки до розділу...110 ВИСНОВКИ...111 ПЕРЕЛІК ПОСИЛАНЬ...113

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Dahmén, Viktor, Martin Holgersson, Aron Larsson, and Joel Norman. "How bright does the sun shine over Storvreta IK? : Mapping the energy use of a local Swedish sports club." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-295100.

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In 2011 Storvreta IK installed two solar collector systems in order to reduce the club’s electricity demand for domestic hot water. However, electricity use from 2012 to 2015 shows that the expected reduction in the electricity demand has not occurred. This project investigates the solar collector systems and the heat demand of Storvreta IK’s buildings in order to explain the “failure” in electricity savings. The results of the simulations show that the heat production of the solar collectors is lower than Storvreta IK’s expectations. This could be explained by that the domestic hot water is not used as much as Storvreta IK thought and the system is therefore over-dimensioned for their need. The rebound effect could be another reason to why the electricity saving is lower than expected.

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Воронцов, Михайло Геннадійович, and Mykhailo Vorontsov. "Ефективність застосування геліопанелей періодичної дії, суміщених із покриттям будівель." Master's thesis, ТНТУ імені Івана Пулюя, 2019. http://elartu.tntu.edu.ua/handle/lib/29984.

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Диплoмнa poбoтa пpисвячeнa eфeктивнoстi зaстoсувaння систeми тeплo-пoстaчaння iз гeлioпaнeлями для пpивaтнoгo будинку щo дaлo мoжливiсть знизити вapтiсть oтpимувaнoї eнepгiї для систeми сoнячнoгo тeплoпoстaчaння. В poбoтi впepшe зaпpoпoнoвaнo кoнстpукцiю гeлioпaнeлi систeми сoнячнoгo тeплoпoстaчaння, кoнстpуктивнo пoєднaну з пaнeллю пoкpиття будiвлi, якa xapaктepизується висoкими тeплoaкумуляцiйними влaстивoстями.
The thesis is devoted to the efficiency of the heat supply system with heliop panels for a private house, which made it possible to reduce the cost of the energy received for the solar heating system. In the work for the first time the solar panel solar panel construction, constructively connected with the panel covering the building, which is characterized by high heat accumulation properties, was proposed for the first time.
ПЕРЕЛІК УМОВНИХ СКОРОЧЕНЬ...8 ВСТУП...9 РОЗДІЛ 1 ЛІТЕРАТУРНИЙ ОГЛЯД...13 1.1. Аналіз сучасних конструкцій сонячних установок...13 1.1.1. Плоскі сонячні колектори...15 1.1.2. Вакуумні сонячні колектори...17 1.1.3. Концентруючі сонячні колектори...20 1.1.4. Комбіновані сонячні колектори...21 1.2. Аналіз сучасних систем сонячного теплопостачання...23 1.2.1. Системи з активним використанням сонячної енергії...24 1.2.2. Панівні сонячні системи...27 1.2.3. Комбіновані сонячні системи...28 1.3. Методи розрахунку сонячної енергії та досліджень сонячних колекторів...31 1.4. Висновки до розділу 1...36 РОЗДІЛ 2. ОСНОВНА ЧАСТИНА...38 2.1. Аналітичні дослідження термоакумуляції геліопанеллю...38 2.2. Розрахунок теплопоглинання геліопанелі...46 2.3. Дослідження ефективності системи сонячного теплопостачання із геліопанелями...50 2.4. Дослідження ССТ із геліопанелями...60 2.5. Застосування систем сонячного теплопостачання із геліопанелями...66 2.6. Використання геліопанелей для гарячого водопостачання...68 2.7. Висновки до розділу 2...71 РОЗДІЛ 3. СПЕЦІАЛЬНА ЧАСТИНА...73 3.1. Методика розрахунку параметрів системи сонячного теплопостачання...73 3.2. Програма розрахунку параметрів системи сонячного теплопостачання з геліопокрівлею...78 3.3. Висновки до розділу 3...89 РОЗДІЛ 4. ОБГРУНТУВАННЯ ЕКОНОМРІНОЇ ЕФЕКТИВНОСТІ...91 4.1. Техніко-економічннй аналіз ефективності застосування геліопокрівлі...91 4.2. Розрахунок економічного ефекту від використання геліопокрівлі...93 4.3. Висновки до розділу 4...98 РОЗДІЛ 5. ОХОРОНА. ПРАЩ ТА БЕ ЗПЕКА В НАДЗВИЧАЙНИХ СИТУАЦІЯХ...99 5.1. Охорона праці та техніка безпеки при будівництві та експлуатації систем опалення...99 5.1.1. Охорона праці та техніка безпеки при монтажі систем опалення...99 5.1.2. Правила безпеки при експлуатації систем опалення...102 5.2. Аналіз факторів ризику при експлуатації систем сонячного теплопостачання...106 5.3. Заходи для забезпечення електробезпеки...108 5.4. Заходи для запобігання виникнення пожежі...110 5.5. Фактори, що впливають на протипожежну стійкість об'єкту...111 РОЗДІЛ 6. ЕКОЛОГІЯ...115 6.1. Вплив систем сонячного теплопостачання на навколишнє середовище...115 6.2. Забезпечення екологічної безпеки систем сонячного теплопостачання...117 ВИСНОВКИ...123 ПЕРЕЛІК ПОСИЛАНЬ...125

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48

Moummi, Abdelhafid. "Etude globale et locale du rôle de la géométrie dans l'optimisation des capteurs solaires plans à air." Valenciennes, 1994. https://ged.uphf.fr/nuxeo/site/esupversions/3e717f2f-e09a-4b1a-af50-e618b869f5dc.

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Les capteurs solaires plans à air, présentent de faibles performances thermiques comparativement aux capteurs à liquides. Cet inconvénient est dû aux faibles propriétés thermophysiques de l'air. Pour accroitre ces performances, on doit créer des écoulements turbulents très développés. Cela permet d'améliorer nettement l'échange thermique et par conséquent les performances des capteurs. Ces écoulements turbulents sont obtenus en garnissant le conduit de l'insolateur par des obstacles les chicanes de formes diverses et variées, réalisées en tôles d'aluminium d'épaisseur 0,4 mm. C'est ainsi qu'un certain accent a été mis sur des chicanes de formes rectangulaires, et suivant certaines dispositions spécifiques, ont permis d'obtenir de très nettes améliorations des performances. En plus du calcul du rendement et du coefficient global des déperditions thermiques, il a été jugé utile de relever la distribution des températures à plusieurs endroits, le long de l'écoulement du fluide caloporteur, étant donné que le coefficient d'échange moyen, par son aspect global, ne permet de localiser dans l'espace total de l'échange, à l'intérieur du capteur, les zones de faible transfert thermique. Ces relevés nous donnent une indication sur la qualité du transfert, une information sur le régime d'écoulement, au niveau des différentes cellules créées par la disposition de ces obstacles. Les choix adéquats des configurations, de la disposition (la plus homogène possible) des chicanes en particulier, créent le plus de désordre dans le conduit du capteur, et favorisent ainsi un meilleur échange entre le fluide caloporteur et l'absorbeur

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49

Zeman, Radek. "Spojení kondenzačního kotle se solárními kolektory pro zásobování RD tepelnou energií." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254319.

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This diploma thesis deals with practical design of heat supply of real house in Libhošť, Nový Jičín. Main strategy of heat supply is gas condensation boiler, that replaces current gas boiler, with solar collector. From known house heat loss we determine temperatures of heating water and power of boiler, that heats the house and hot water. System with solar collector is designed to heat hot water in the house. All necessary equations are calculated both for long term measured meteorological data and for data in year 2015. Heat gains and payback periods of investment in solar system are determined from them. Payback periods are calculated given to price of heat that gas boiler produces. Equations and payback period evaluation are made for systems with one to four solar collectors. There is recommendation at the end of thesis, whether the solar system is advantageous, or not.

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50

Kučera, Miroslav. "Moderní energie a snížení energetické náročnosti budov." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217951.

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This diploma thesis deals with possible energy-savings in the municipal buildings of Spytihněv. Moreover, it discusses the possible improvements of heating features and making use of renewable resources. This is meant to be achieved by a wrapper which is less demanding on energy consumption than those which have been used until now. Attention is also paid to a more efficient system of energy distribution. Both energetic and financial points of view are taken into consideration. The thesis consists of a few parts. Introduction, the first part, deals with renewable resources issues on a theoretical level. The second part is divided according to each individual analysed premise/building. At this point energy-saving proposal, choice of a heating system, a heating pump, a solar collector as well as energy-saving and financial calculation are included.

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