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1
Stewart, Alistair Henry. "An assessment of financial incentives for encouraging South Africa's domestic solar water heater market." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/8987.
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Includes bibliographical references (p. 102-104).SA has a demand for domestic hot water, which is supplied by a number of different technologies. For a number of reasons, including health reasons and versatility, Government has encouraged the demand for electricity to meet domestic requirements. But currently there is a shortage of electricity supply, with negative impacts for the development of SA. Solar water heating (SWH) is a renewable energy technology that could relieve some of the demand for electricity, and the aim of this study is to assess which types of national financial incentive programmes should be implemented in order to encourage the use of SWH systems in households, within the context of SA's energy policy and the current electricity crisis. However, only hybrid SWH technologies were considered, due to a lack of information. A review of literature shows that domestic SWH technology use is uncommon, resulting from households preferring other technologies for reasons of cost and convenience. The modelling of current and hypothetical scenarios of energy consumption for domestic water heating show that the increased use of hybrid SWH technology would benefit SA's sustainable development. A literature review was used to identify the barriers stopping these benefits from being translated into the domestic sector. A literature review of energy policy documents confirmed SA's commitment to sustainable development and introduced a number of developments intended to reduce the barriers to renewable energy technologies. Investment incentives and set-asides were identified as potential financial incentive options for SA. A literature review of the SWH market identified the existing structures and capacity of expertise, and identified options for reducing SWH barriers. A criteria analysis was performed on a set-aside option and investment incentive options, which included a direct subsidy, an income tax deduction, and an interest rate subsidy. The criteria used for this analysis were derived from this study and a report of international experiences, and the analysis provided an assessment of the suitability of each of these financial incentives. The assessment resulted in the recommendation that a direct subsidy programme be implemented, possibly using a system of Tradable Renewable Energy Certificates (TRECs), which could allow for compatibility with developments that could enhance the success of the programme.
2
Guarnieri, Raniero Alberto. "Novel approaches to the design of domestic solar hot water systems." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16056/1/Raniero_Guarnieri_Thesis.pdf.
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Domestic solar hot water units, if properly designed, are capable of providing all hot water needs in an environmentally friendly and cost-effective way. Despite 50 years of development, commercial technology has not yet achieved substantial market penetration compared to mainstream electric and gas options. Therefore, alternate designs are warranted if they can offer similar or greater performance for a comparable cost to conventional units. This study proved that such alternatives are possible by designing and testing two novel solar hot water systems (SHWS). The first system used compound parabolic collector (CPC) panels to concentrate solar energy and produce steam. The steam moved from a rooftop downward into a heat exchange pipe within a ground level water tank, heating the water, condensing and falling into a receptacle. The operation was entirely passive, since the condensate was pulled up due to the partial vacuum that occurred after system cooling. Efficiencies of up to 40% were obtained. The second system used an air heater panel. Air was circulated in open and closed loop configuration (air recycling) by means of a fan/blower motor and was forced across a compact heat exchanger coupled to a water tank. This produced a natural thermosiphon flow heating the water. Air recycling mode provided higher system efficiencies: 34% vs. 27%. The concurrent development of an analytical model that reasonably predicted heat transfer dynamics of these systems allowed 1) performance optimisation for specific input/starting operating conditions and 2) virtual design improvements. The merit of this model lay in its acceptable accuracy in spite of its simplicity. By optimising for operating conditions and parameter design, both systems are capable of providing over 30 MJ of useful domestic hot water on clear days, which equates roughly to an increase of 35°C in a 200 L water tank. This will satisfy, on average, daily hot water requirements for a 4-person household, particularly in low-latitude regions (eg. Queensland). Preliminary costing for these systems puts them on par with conventional units, with the passive, remotely coupled, low maintenance, CPC SHWS comparable to higher end models. The air heater SHWS, by contrast, was much more economical and easier to build and handle, but at the trade-off cost of 1) the need for an active system, 2) increased maintenance and running costs and 3) the requirement for a temperature control mechanism that would protect the panel body by dumping hot air trapped inside if stagnation were to occur.
3
Guarnieri, Raniero Alberto. "Novel Approaches to the Design of Domestic Solar Hot Water Systems." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16056/.
Full textAbstract:
Domestic solar hot water units, if properly designed, are capable of providing all hot water needs in an environmentally friendly and cost-effective way. Despite 50 years of development, commercial technology has not yet achieved substantial market penetration compared to mainstream electric and gas options. Therefore, alternate designs are warranted if they can offer similar or greater performance for a comparable cost to conventional units. This study proved that such alternatives are possible by designing and testing two novel solar hot water systems (SHWS). The first system used compound parabolic collector (CPC) panels to concentrate solar energy and produce steam. The steam moved from a rooftop downward into a heat exchange pipe within a ground level water tank, heating the water, condensing and falling into a receptacle. The operation was entirely passive, since the condensate was pulled up due to the partial vacuum that occurred after system cooling. Efficiencies of up to 40% were obtained. The second system used an air heater panel. Air was circulated in open and closed loop configuration (air recycling) by means of a fan/blower motor and was forced across a compact heat exchanger coupled to a water tank. This produced a natural thermosiphon flow heating the water. Air recycling mode provided higher system efficiencies: 34% vs. 27%. The concurrent development of an analytical model that reasonably predicted heat transfer dynamics of these systems allowed 1) performance optimisation for specific input/starting operating conditions and 2) virtual design improvements. The merit of this model lay in its acceptable accuracy in spite of its simplicity. By optimising for operating conditions and parameter design, both systems are capable of providing over 30 MJ of useful domestic hot water on clear days, which equates roughly to an increase of 35°C in a 200 L water tank. This will satisfy, on average, daily hot water requirements for a 4-person household, particularly in low-latitude regions (eg. Queensland). Preliminary costing for these systems puts them on par with conventional units, with the passive, remotely coupled, low maintenance, CPC SHWS comparable to higher end models. The air heater SHWS, by contrast, was much more economical and easier to build and handle, but at the trade-off cost of 1) the need for an active system, 2) increased maintenance and running costs and 3) the requirement for a temperature control mechanism that would protect the panel body by dumping hot air trapped inside if stagnation were to occur.
4
Singh-Chhabra, Mohit. "Solar domestic hot water heater performance| Effect of changing annual load and average use profile." Thesis, University of Colorado at Boulder, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1589994.
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The objective of this research is to understand, using computer simulation, the effects of changing domestic hot water load and usage patterns on the system performance of active and passive solar domestic hot water (SDHW) systems. Annual hot water load, mains water temperature, daily hot water load profile shape, and daily hot water load were the parameters varied to simulate variations in load and usage patterns that we expect would occur in a household. The effect of changing these parameters was quantified by studying change in annual solar fraction and annual system efficiency.
Active and passive SDHW system construction was first defined. The system components of both active and passive system solar hot water systems simulated were determined by market research. The components were sized adequately using accepted component sizing guidelines. Daily hot water draw profiles developed at NREL (National Renewable Energy Laboratory) were used as the base draw profiles. The base profile has morning and evening hump and a daily hot water load of 60 gallons on weekdays and 75 gallons on weekends. The annual simulations were conducted in TRNSYS using a five minute time-step.
Active (glycol) systems show greatest variation in simulated performance due to large changes in annual load. Passive (ICS) systems display high sensitivity to hot water profile shape. This difference between the two systems is due to the presence of a well-insulated solar storage tank in the glycol system.
The glycol system shows less variation in performance due to variation in draw profile than the ICS system due to the presence of an appropriately sized and insulated solar storage tank in the glycol system. The solar storage tank helps glycol systems meet the demand for hot water during hours of low sunlight (early morning and late evening). ICS systems show higher sensitivity to profile shape as they cannot meet hot water load during morning and evening times; this morning and evening hot water load is met by the auxiliary heating tank.
5
Cemo, Thomas A. Van Treuren Kenneth W. "Design and validation of a solar domestic hot water heating simulator." Waco, Tex. : Baylor University, 2009. http://hdl.handle.net/2104/5357.
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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
7
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.
8
Wells, Karen Wilk. "Experimental investigation of nighttime losses from ICS solar domestic hot water systems." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/104661.
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The nighttime losses from an integral collector storage (ICS) system were investigated. The significance of the sky temperature, wind speed, and ambient temperature on the losses were examined. Outdoor data was taken on several nights to characterize the thermal performance of an ICS system under various environmental conditions. Indoor tests were then performed under an artificial "nighttime sky" environment, with a simulated wind, in an attempt to duplicate the heat losses which occurred outdoors.
The standard rating procedure which specifies the conditions for the heat loss tests for ICS systems was analyzed to see how well it characterizes the collector performance at night. Experimental results indicate a synergistic effect between the sky temperature and wind speed. The effects of wind on the losses from the ICS system overshadow the effects of small changes in sky temperature, but larger changes of sky temperature, with a constant wind speed, have a pronounced effect.
It is recommended that both of these parameters be taken into account in heat loss tests in standard rating procedures. Indoor tests can duplicate outdoor heat loss results within 8 per cent. The minimum requirement for SRCC rating tests should be to monitor, record, and report the sky temperature.M.S.
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Purdy, Julia Mary. "Thermal modelling of plate heat exchangers in natural convection solar domestic hot water systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0002/MQ36072.pdf.
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Youssef, Walid Mohamed Khalil Abdalla. "Experimental and computational study of indirect expansion solar assisted heat pump system with latent heat storage for domestic hot water production." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/15263.
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Solar assisted heat pump (SAHP) systems have been widely applied in domestic hot water (DHW) production due to their sustainability and stability in operations. However, their performance efficiency requires further improvement using advanced technologies such as energy storage with phase change materials (PCM) and optimal system controls. Undoubtedly, employing PCMs for latent heat storage (LHS) application has a great potential to improve a solar thermal application performance. Despite this fact, the use of PCM in this area is quite limited due to the poor thermal conductivity of available PCMs. Therefore, heat transfer enhancement is one of the essential strategies that can overcome this obstacle. Accordingly, a test rig of a new indirect expansion solar assisted heat pump (IDX-SAHP) system has been designed, built and instrumented. The system can handle heating capacity up to 9 kW. The IDX-SAHP system consists of three operational loops: solar thermal, solar-air assisted heat pump and load profile. A 2 kW PCM heat exchanger (HX) was purposely designed and installed in the system solar thermal loop to store solar energy, when applicable, and release heat when required by the heat pump. The PCM HX is employed with a novel heat transfer enhancement method. The maximum coefficient of performance (COP) of the IDX-SHAP system reached 4.99 during the sunny day with the PCM (HX) integration. However, the maximum energy saving was achieved during the cloudy day with the PCM HX integration. Moreover, the proposed heat transfer enhancement method has been modelled through CFD package and validated with the experimental results. This allows a clear understanding of the reasons for the longer discharging process compared with the charging process. Furthermore, the inlet flow rate and temperature variation of the PCM HX was simulated during charging and discharging processes. The optimum inlet flow rate for this application was found at 0.1 kg/s while the optimum inlet temperature was found at 40°C. Meanwhile, the whole system was modelled by the coupling of TRNSYS, EES and CFD to investigate the potential and advantages of using the system in locations with rich solar intensity such as Cairo and Madrid. The simulation shows that the solar thermal operation loop was called more frequently in these locations. This had a significant impact on the system energy consumption, especially during winter. The maximum COP and solar performance factor (SPF) of the modelled system were 5.3 and 0.83 respectively.
11
Lundh, Magdalena. "Domestic heating with solar thermal studies of technology in a social context and social components in technical studies /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-101325.
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Junaidi, Haroon. "Optimized solar water heater for Scottish weather conditions." Thesis, Edinburgh Napier University, 2007. http://researchrepository.napier.ac.uk/Output/3799.
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The ICSSWH (Integrated Collector Storage Solar Water Heater), apart from being the oldest is also the most economical means of solar water heating. The effect of modifications in the collector geometry has frequently appeared in the literature, and over the time, has resulted in different designs. These designs differ mainly on the site of installation as well as the target application. A novel design created by Professor T Muneer at Napier University, utilizes fins inside the storage tank to improve the heat transfer. The reported field tests of the fin type ICSSWH have indicated a 10 % improvement in the solar fraction compared to unfinned. As ICSSWH is the lowest cost, it presented a possible solution for the Scottish market where Energy Saving Trust estimates that 50% of hot water demand of a household can be met through solar water heating. In the present research program, two prototype collectors (one with- and one without fins) were fabricated at Napier University by the author. The collectors were then tested in the laboratory on identical experimental schemes to determine their respective performance. Simulations based on analytical modelling were then undertaken, using numerous experimental data for validation that were obtained during the course of the present work. A high degree of conformance was noted between the two. Furthermore, for a deeper insight, Computational Fluid Dynamics (CFD) analysis was performed. This research focuses on the qualitative and quantitative assessment of the heat transfer due to the fins. The difference in the performance with respect to the change in tilt angle was also studied. This study can therefore be utilised for developing solar water heating systems for any given location. Note that there is an intrinsic link between the latitude and inclination angle of the collector plate. The nocturnal loss from the collector is the principal factor that has inhibited the wide spread use of the ICSSWH. The remedies to abate this problem have therefore been attempted. In addition to that, the collectors have to be integrated with the domestic hot water supply system and plumbing considerations have to be incorporated within the overall design. The supply circuits were worked out and the measures for freeze and boil protection were devised. The optimization of any system is an intrinsic task particularly when several variables are involved. On the basis of the obtained results from simulations and experiments, the influential design variables were identified. The values for these variables which lead to the optimal design in terms of thermal performance were assessed while keeping the overall manufacturing cost of the collector as low as possible. Recommendations for future work have also been presented.
13
Grassie, Tom. "Optimisation of fluid-flow in a flat plate solar water heater." Thesis, Edinburgh Napier University, 2001. http://researchrepository.napier.ac.uk/Output/3862.
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Hobson, P. A. "Thermosyphon solar water heaters : validated numerical simulation and design correlations." Thesis, Cranfield University, 1988. http://hdl.handle.net/1826/4361.
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A detailed analysis of the heat transfers and fluid flows within a
direct thermosyphonic solar-energy water-heater has been undertaken.
The collector energy equations when cast in a two-dimensional form
enabled heat transfer and thermal capacitance effects to be simulated
accurately at the small flow rates encountered commonly in such
systems. An investigation of thermocline relaxation processes within
the store indicated negligible mixing at the store inlet over a wide
range of Richardsons numbers (43,608 < Ri < 729,016). Thermal
relaxation under conditions of no flow was shown to be due
predominantly to axial conduction along the store wall. The use of an
appropriate non-isothermal friction factor correlation when calculating
frictional losses in the collector's riser pipes, produced predicted
steady-state flow rates which were corroborated experimentally to
within 2%. An indoor test facility, monitored and controlled by a
microcomputer, enabled "real" operating conditions to be simulated. The
predicted responses of the system to identical conditions showed good
agreement with the corresponding experimental observations, the
predicted heat delivery being within 2.8% of the measured value.
A technique for correlating the daily performances of thermosyphon
solar-energy water-heaters has been developed. The five dimensionless
groups which form the basis of the correlations and the functional
relationships between these groups were derived from an analytical
solution of a linear first-order differential transient heat balance
carried out on a generic system. Thermal performance data used in the
correlations was generated by the numerical simulation using
representative U. K. hourly weather data and operating conditions. The
minimum amount of data required to establish a characteristic curve for
an individual system was found to be thirty days. Using such a curve,
the total annual solar fraction agreed with that predicted by the high
level model to within 3%. Two universal curves were determined in which
the gradients of characteristic curves were correlated against the
derived dimensionless groups. The accuracy of the resulting two-stage
algorithm in determining annual solar fractions was established as
ranging from 5.5% for predominantly multiple-pass systems to a mean of
10.5% for single-pass systems.
15
Smyth, Mervyn A. "Design and development of a heat retaining integrated collection/storage solar water heater." Thesis, University of Ulster, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264693.
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Hardie, Mignon. "Developing SA's solar water heater industry : identifying key success factors for future growth." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/8509.
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Thesis (MBA)--University of Stellenbosch, 2011.The government has stated its intentions to increase the usage of solar water heating (SWH) through its National Solar Water Heater Programme (NSWHP). As described in the report, increased adoption of SWH would have a number of benefits for South Africa. Firstly, replacement of electric geysers by SWHs would contribute to the meeting of energy efficiency targets through the reduction of energy consumption. Secondly, the widespread adoption of SWHs would help SA to meet its renewable energy targets. Thirdly, it would result in growth in the SWH industry, including the manufacturing, installation and related sectors, thereby contributing to an increase in 'green' jobs. It would have the socio-economic benefit of energy security for South Africans. The research report looks at the factors influencing the SWH industry's future growth from the point of view of the suppliers. It considers the interplay between consumers (market demand), government (public policy measures) and suppliers (businesses providing services related to SWH) to determine how government can support industry, how suppliers can grow their business and industry and how government and industry can work together to create the conditions for sustained market demand. As is discussed in the literature review, there are certain barriers to the adoption of SWH technology. As such, government intervention is needed to help overcome these barriers. The literature review recounts the available policy tools and considers how these have been applied in other countries to stimulate demand for SWHs and to support the local industry. The research report takes the form of a survey of SWH suppliers with the following aims: - To describe the industry in terms of its age, maturity and ability to scale up; - To determine the major barriers to the industry's growth; - To specify the appropriate public policy tools to overcome these obstacles to growth; - To establish how confident the industry is in the NSWHP and government efforts to promote the industry; - To provide a list of key success factors that are required for the industry's long-term, sustainable development. The report concludes that there are three criteria that would help the industry to become sustainable: market demand certainty, investment confidence and positive competition. Certainty of future market demand would build confidence in the industry for investors. In turn, increased investment would benefit the forces of positive competition.
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Magnusson, Erik, and Johan Schedwin. "Development of solar water heating system." Thesis, Högskolan i Skövde, Institutionen för teknik och samhälle, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-4428.
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This report includes development of an already designed solar water heater. The product shall be constructed in a way that it will suit a manufacturing line in Kampala, Uganda. To find the most suitable design for each area a research was carried out which included study visits, interviews and background reading. It provided the following results: Regarding the attachment of in- and outgoing pipes from the water tank many methods were taken into consideration and it was found that the best and most suitable way for this case is to weld the fittings using a weld robot. Regarding the fitting of the acrylic, a suitable solution is to make a flange when vacuum forming the plastic casing to further support the design. This could also be used to waterproof the case by using a sealing material. A suggestion of using pre-molded PU-foam is also presented. Regarding the ability to open the case for maintenance, two solutions were recommended. Either the use of spire clips or having the clips integrated into the casing. Regarding the calculation of material usage when deep drawing the tank and collector, it is possible to do a reasonably accurate assumption. The complicated design in this product makes the estimation less accurate. It is recommended that test draws are done and often the machine producer has more precise numbers. Regarding the coloring of the collector; chemical coloration is not possible on a galvanized surface. The method used is painting, either with powder coating or with wet paint.
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Jesudhason, Maria Therasammal Terry Bruno. "Analysis of the Impact of Solar Thermal Water Heaters on the Electrical Distribution Load." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/35302.
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In this research, the impact of solar thermal water heaters on the electric water heating load curve in a residential distribution circuit is analyzed with realistic hot water draw profiles. For this purpose, the electric and solar thermal water heater models are developed in MATLAB and validated with results from GridLAB-D and TRNSYS respectively. The solar thermal water heater model is developed for two types of collectors namely the flat plate and evacuated glass tube collector. Simulations are performed with the climate data from two cities - Madison, WI and Tampa, FL - which belong to two very different climate zones in the United States. Minute-by-minute electric energy consumptions in all three configurations of water heaters are modeled for a single water heater as well as a residential distribution circuit with 100 water heaters for daily as well as monthly time frames.The research findings include:
- The electric energy saving potential of a solar thermal water heater powered by auxiliary electric element is in the range of 40-80% as compared to an all-electric water heater depending on the site conditions such as ambient temperature, sunshine and wind speed. The simulation results indicate that the energy saving potential of a solar thermal water heater is in the range of 40-70% during winter and 60-80% during summer.
- Solar thermal water heaters aid in reducing the peak demand for electric water heating in a distribution feeder during sunshine hours when ambient temperatures are higher. The simulation results indicate that the peak reduction potential of solar thermal water heaters in a residential distribution feeder is in the range of 25-40% during winter and 40-60% during summer.
- The evacuated glass tube collectors save an additional 7-10% electric energy compared to the flat plate collectors with one glass pane during winter and around 10-15% during summer. The additional savings result from the capability of glass tube collectors to absorb ground reflected radiation and diffuse as well as direct beam radiation for a wider range of incidence angles. Also, the evacuated glass tube structure helps in reducing wind convective losses.
- From the simulations performed for Madison, WI and Tampa, FL, it is observed that Tampa, FL experiences more energy savings in winter than Madison, WI, while the energy savings are almost the same in summer. This is due to the fact that Tampa, FL has warmer winters with higher ambient temperatures and longer sunshine hours during the day compared to Madison, WI while the summer temperatures and sunshine hours are almost the same for the two cities.
- As expected, the simulation results prove the fact that lowering the hot water temperature set point will result in the reduction of electricity consumption. For a temperature reduction from 120 deg. F to 110 deg. F, electric water heaters save about 25-35% electric energy whereas solar thermal water heaters save about 30-40% auxiliary electric energy for the same temperature reduction.
- For the flat plate collectors, glass panes play an important role in auxiliary electric energy consumption. Flat plate collectors with two glass panes save about 10-15% auxiliary electric energy compared to those with no glass panes and about 3-5% energy saving compared to collectors with one glass pane. This is because there are reduced wind convective losses with glass panes. However, there are also transmittance losses from glass panes and there are upper limits on how many glass panes can be used.
Master of Science
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Albarghouthi, Mohammad Talha. "Optimization of hydraulics and photovoltaics in a solar water heater with photovoltaic-powered pump." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ31541.pdf.
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Williamson, George Bernard. "Comparison of measured to predicted performance of owner-built solar integral collector storage water heater systems." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/101361.
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This study presents a comparison of field measurements of energy delivered by five integral collector storage (ICS) passive solar water heater systems installed at various geographic locations in Virginia to predicted values calculated using Annual Performance Methodology (APM). APM is a prediction method developed by Alan Zollner that offers quick and easy comparisons of design option for ICS systems.
Several different methods exist today that are meant to predict the performance of this type of system and that might be used as a design tool to help a designer make appropriate design decisions. Some of these methods are quite complicated and do not lend themselves to quick and easy comparisons of various design options.
This study measured the amount of energy delivered by five ICS systems over a six month period. The amount of water drawn out of these systems daily was also recorded. This data was compared to predicted values calculated using APM to determine if APM could predict the performance of these systems within plus or minus 15 percent of the measured values.
This study demonstrates that APM was able to predict long term performance of ICS systems within plus or minus 15 percent eighty percent of the time. Short term performance however demonstrated variation that in some cases were quite large and could not be considered reliable predictions.M. Arch.
21
Dharanikota, Sai Mahesh. "Experimental Test and Cost Analysis of Residential Solar Water Heaters." Cleveland State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1236123539.
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Rony, Mohammad Rajib Uddin. "Numerical Analysis of a PV/Microchannel Integrated CO2 Direct-Expansion Heat Pump Water Heater." Thesis, North Dakota State University, 2019. https://hdl.handle.net/10365/31698.
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A steady-state numerical model of a PV/microchannel integrated direct-expansion CO2 heat pump (PV-DXHP) water heater is developed, validated, and analyzed in the present study. To accomplish the objectives, a numerical model of a microchannel evaporator integrated into a CO2 PV DXHP is developed and validated. The effects of evaporator operating parameters on the heat absorption and pressure drop are analyzed. Utilizing the evaporator model, the PV-DXHP model is developed, and the baseline values of the heat pump operating parameters are determined from the evaporator parametric study. The PV-DXHP demonstrates high water heating capability, while maintaining a reasonably high COP. The COP has the highest dependency on the CO2 mass flow rate, while the water outlet temperature has the highest dependency on the water mass flow rate. The results are highly promising and indicate the system has potential to help meet the energy requirements for residential and industrial water heating demands.
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Kritzinger, Karin. "Exploring the possibility of the insurance industry as a solar water heater driver in South Africa." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6471.
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Thesis (MPhil)--University of Stellenbosch, 2011.ENGLISH ABSTRACT: South Africa is facing an energy crisis on two levels; the existing capacity to supply electricity is unable to support future growth in demand, and the electricity being produced comes mostly from coal-fired power stations with associated emission problems. The South African government has a target for renewable energy to service 23% of the country’s energy consumption by 2013. This could potentially be realised through achievement of another government target, the installation of one million Solar Water Heaters (SWHs). On a technical level, Solar Water Heaters (SWHs) represent a completely viable renewable energy alternative for South Africa. It is an established and proven technology which has the potential to have a big impact on the country’s electricity capacity problems. SWHs can be used in a variety of applications from industry to households. Most of the hot water in South African homes is heated by electric resistance heating in standard electric water heaters and there are no technical obstacles to replacing most of these with SWHs, thereby delivering a saving of up to 70% of the water heating energy bill. Water heating currently accounts for 40% of domestic electricity consumption within a residential sector that uses 20-30% of the national supply. At the macroscale, the roll out of SWH programmes is completely scalable. The benefits of SWH installation accrue to the consumer in the form of a financial saving in the long-term and to society in the form of reduced emissions. Awareness of the benefits is growing amongst the general public, commercial institutions and in government. Sales are starting to pick up due to, amongst other reasons, electricity price hikes and government subsidies for SWH installations offered through the national electricity supply company, Eskom. A national building regulation enforcing energy-efficient water heating in new buildings has been drafted and is expected to be in place by mid 2011. The rate of change from electric to solar water heaters remains disappointingly slow, however. The SWH industry in South Africa accounts for less than 10% of total hot water solutions sold. This study sought to establish the opportunities as well as possible barriers for the creation of SWH programmes within the insurance sector. Close to 50% of all standard electric water heaters installed in South Africa are procured and installed via the insurance industry due to the failure of units that have endured beyond the manufacturer’s guarantee period. This presents an opportunity for interventions that encourage policyholders to change to SWHs. Such interventions, if successful, would dramatically speed up the roll out of SWHs in South Africa. In addition the study sought to determine the barriers to the uptake of SWHs by policyholders in the case of the two insurance companies that currently have SWH programmes in operation. Data was collected through interviews with representatives in the insurance industry and a range of SWH industry stakeholders and consumers. The literature review focused on SWH policies and regulations and corporate and marketing theories. The material on transition in socio-technological systems proved especially useful in understanding the complex dynamics of the study topic. The conclusion drawn from the research is that the South African insurance industry has the capacity and opportunity to drive the penetration of SWH technology. The opportunity is, however not being exploited to anywhere near its potential. The entire system is geared towards providing a particular ‘business-as-usual’ solution. Analysis conducted in this study confirms that the system is in a “locked-in” state and extremely resistant to change. If the opportunity is to be acted on, to supplant the dominant technology for water heating installed by the insurance industry with what is currently a niche technology (SWHs), an external landscape shock is almost certainly needed. This shock to the system could be aided by interventions that target a change in the current system’s logic. The study provides some suggestions in this regard.
AFRIKAANSE OPSOMMING: Suid-Afrika staar ‘n energie krisis in die gesig. Aan die een kant is die bestaande elektrisiteitsvoorsiening nie genoeg om plek te maak vir die toekomstige vraag na elektrisiteit nie en aan die ander kant word meeste van Suid-Afrika se elektrisiteit opgewek deur steenkoolaangedrewe kragstasies met gevolglike probleme as gevolg van vrylating van kweekhuis-gasse. Die Suid-Afrikaanse regering het ‘n teiken vir hernubare energie om 23% op te maak van die land se totale energie verbruik teen 2013. Hierdie teiken sou potensieel bereik kon word deur die bereiking van ‘n ander van die land se teikens, naamlik die instalering van een miljoen sonverhitters. Op ‘n tegniese vlak verteenwoordig sonverhitters ‘n lewensvatbare hernubare energie alternatief vir Suid-Afrika. Dit is ‘n beproefde tegnologie wat die potensiaal het om ‘n groot impak te hê op die elektrisiteit kapasiteitsprobleme van die land. Sonverhitters kan ‘n verskeidenheid van warm water behoeftes bevredig, van groot industrieë tot tuisverbruik. Meeste warm water in Suid-Afrikaanse huise word verhit deur standaard elektriese geisers. Daar bestaan geen tegniese hindernisse om hierdie geisers deur sonverhitters te vervang en tot 70% van die water verhittings energie rekening te bespaar nie. Water verhitting maak tans 40% van die totale huishoudelike elektrisiteits verbruik op. Die huishoudelike verbruik is 20-30% van die nasionale verbruik en selfs hoer gedurende piek. Op die makro skaal is die uitrol van sonverhitters heeltemal skaleerbaar. Die voordele van die installering van sonverhitters val die verbruiker toe in die vorm van finansiele besparing oor die lang termyn en vir die samelewing as geheel in die vorm van emissie besparings. Bewustheid van die voordele is aan die groei by die algemene publiek, kommersiele instansies en by die regering. Verkope het begin optel as gevolg van onder andere die elektrisiteits prysverhoging en die staatssubsidies vir sonverhitters aangebied via die nasionale elektrisiteits toevoer maatskappy, Eskom. A nasionale bouregulasie wat enegie doeltreffende waterverhitting sal afdwing op nuwe geboue is reeds opgestel en dit word verwag dat hierdie regulasie in plek sal wees teen middel 2011. Die koers van verandering van elektriese water verhitters na sonkrag bly egter teleurstellend laag. Die sonverhittings industrie in Suid-Afrika maak minder as 10% van die totale water verhittings mark uit. Hierdie studie het beoog om die geleenthede sowel as die moontlike versperrings tot die skepping van sonverhittings programme in die versekerings bedryf uit te wys. Die versekerings bedryf koop en installeer ongeveeer 50% van alle standaard elektriese geisers in Suid-Afrika as gevolg van elektriese geisers wat breek na die vervaardiger se waarborg verval het . As gevolg hiervan bestaan daar ‘n geleentheid vir intervensies wat polishouers aanmoedig om te verander na sonverhitters. Sulke intervensies, indien suksesvol, het die potensiaal om die uitrol van sonverhitters in die land dramaties te versnel. Verder het hierdie studie beoog om die versperrings tot die opname van sonverhitters uit te wys by twee versekerings maatskappye in Suid-Afrika wat wel sonverhittings programme het. Data is versamel deur onderhoude met verteenwoordigers van die versekeringsbedryf en ‘n reeks sonverhitting industrie belanghebbendes en verbruikers. Die literatuurstudie het gefokus op sonverhittings beleid en regulasies en korporatiese en bemarkings teorie. ‘n Literatuurstudie in oorgang in sosio-tegnologiese sisteme was veral nuttig om die komplekse dinamika van die sisteem te verstaan. Die gevolgtrekking van hierdie studie is dat die Suid-Afrikaanse versekeringsbedryf wel die kapasiteit en geleentleid het om die penetrasie van sonverhittings tegnologie te dryf. Hierdie geleentheid word egter nie gebruik tot sy volle potensiaal nie. Die ganse sisteem is gerat om ‘n spesifieke tegnologie op ‘n sekere manier te verskaf. Analise in hierdie studie bevestig dat die sisteem in ‘n geslote staat is en daar is uiterste teenkanting tot verandering. Indien hierdie geleentheid om die dominate tegnologie vir waterverhitting geinstaleer deur die versekerings bedryf te verplaas met wat op die oomblik nog ‘n niche tegnologie is (sonverhitters), is ‘n eksterne landskap skok nodig. Hierdie skok tot die sisteem kan aangehelp word deur intervensies wat ‘n verandering in die huidige sisteem logika teiken. Hierdie studie bied ‘n paar voorstelle in hierdie verband.
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Islam, Mohammad Raisul. "Numerical Simulation of Direct Expansion Solar-Assisted Heat Pump Water Heater Using Carbon Dioxide as Refrigerant." Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/27050.
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Compared to the conventional solar-assisted heat pump (SAHP) water heating system, a relatively more compact direct-expansion solar assisted heat pump (DX-SAHP) has been introduced, in which the solar collector acts as an evaporator. Details of the analytical studies of a CO2 transcritical cycle on SAHP water heating system are presented in this study. A numerical model has been developed to optimize the system design and operating parameters. The simulation model can predict the performance of the system COP, collector efficiency and heat capacity. An experimental prototype using the evacuated tube U-pipe solar collector utilized to verify the simulation results. The results show that both the solar radiation and ambient temperature have a significant impact on the DX-SAHP system's thermal performance. Year round performance showed that, theoretically, the system could achieve on an average, COP of 2 - 3.2, collector efficiency of 40 - 62% and water temperature to be about 43? - 56?C.Pakistan-US Science and Technology Cooperation Program, US Department of State
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Bakir, Oztekin. "Experimental Investigation Of A Spherical Solar Collector." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607205/index.pdf.
Full textAbstract:
The purpose of this study is to investigate the performance of a spherical solar collector by using numerical and experimental methods. For this analysis, equations were obtained by choosing appropriate control volumes in the system and applying The First Law of Thermodynamics.
The experiments were realized at four different mass flow rates and non-flow situation. For the numerical simulation of the system, a computer program in Mathcad was written. Another computer program in Mathcad was written for the variation of the absorbed solar radiation through out the day.
Finally, the performance of the spherical solar collector is compared theoretically to that of flat plate solar collectors.
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Asim, Muhammad. "Experimental Analysis of Integrated System of Membrane Distillation for pure water with solar domestic hot water." Thesis, KTH, Energiteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-141141.
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In GCC countries, especially in UAE desalination of sea water is considered to be one of the most effective and strategic alternative for satisfying the current and future demand of water for domestic purposes. The depletion of ground water aquifers, rapid industrial development and increase of urban population in UAE lead to tremendous increase in fresh water demand during past decade. Although, desalinated fresh water is supplied to the consumers by local municipalities, people in the region rely mostly on bottled water for drinking purpose obtained through post desalination re-processing. Thousands of suppliers in UAE deliver bottled water to homes or offices thus leading to environmental unsustainability in the whole conversion chain from desalinated water to bottling, packaging and delivery. In fact, UAE is one of the leading countries in per capita bottle water consumption. Therefore, a need has been observed to provide safe drinking water for households in a sustainable way.In order to produce drinking water at homes, a concept of integrating Membrane Distillation (MD) based water purification with Solar Domestic Hot Water (SDHW) systems has been proposed and its feasibility has been evaluated in this research study. Present application is for a single family house/villa in UAE region that requires 20 l/day of drinkable water and 250 l/day of hot water for domestic purpose. An experimental pilot system has been installed at CSEM-uae for evaluating different operational parameters of such integrated system and also to determine overall thermal performance of the system. The study provides detailed design of experimental unit, procurement, installation and commissioning of the SDHW-MD integrated system along with estimated annual profiles of pure water and overall energy consumption.Experiments performed for one month during summer and distillate fluxes of around 4.5 – 12 l/m2/hour has been obtained with optimum MD hot and cold side flow rates of 6 and 3 l/min respectively and at hot side temperatures ranging from 50 - 70oC with cold side average temperature of 35oC. With recovery of cold side heat of MD unit, 25% of daily demand of DHW could be reduced and hence the estimated annual combined energy demand of 8220 kWh could be sufficiently fulfilled with either 8.5 m2 aperture area of Flat plate solar thermal collectors or with 7.5 m2 of Evacuated tubular collectors.
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Dall'Antonia, Junior Luiz Carlos [UNESP]. "Coletor solar alternativo de concreto para aquecimento de água em aplicações agrícolas e agroindustriais." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/90488.
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O presente trabalho descreve a construção de um coletor solar alternativo de concreto de tração simples (areia, cimento e pedra), para aplicações agrícolas e agroindustriais. o coletor é constituído de uma área de absorção 51 m2 com 470m de mangueira de polietileno para o aquecimento da água, e o armazenador da água aquecida. O sistema coletor e armazenador foi submetido a testes experimentais onde foram determinados para as estações verão e inverno, e sob três coberturas de céu aberto, parcialmente nublada e nublada: as temperatura do absorvedor em três profundidades; ganho térmico do fluido; rendimento térmico do coletor, e desempenho do armazenador. Os resultados mostram que a temperatura do absorvedor foi maior na cobertura de céu aberto, decrescendo em seqüência de profundidade 55,74ºC, 52,10C e 49,30C respectivamente, e foi menor na cobertura de céu nublado, 48,30C, 46,20C e 44,60C respectivamente; o ganho térmico do fluido de trabalho no absorvedor foi decrescente em função do aumento comprimento do condutor: o ganho foi maior no verão e em dias de céu aberto, atingindo a temperatura máxima de 52,70C, e foi menor no inverno, em dias céu nublado, atingindo a temperatura máxima de 28,50C; o rendimento térmico do coletor foi maior em dia de céu aberto: no verão 71,4% e inverno 74%; o sistema armazenador térmico, mostrou ótimo desempenho na conservação da temperatura do fluido de trabalho. Nos dias estudados houve uma redução de 10% na temperatura final da água aquecida
This paper describes the construction of an alternative sidewalk-type solar collector made of concrete (sand, cement and stone), for agriculture and agribusiness uses. The collector consists of an absorption area of 51 m2 with 470m polyethylene tubing for water heating, and a storage for warm water. The collector and storage systems were subjected to experimental tests which were determined for summer and winter, three sky conditions: open skies, partly cloudy and overcast; three depths temperature in the absorber; thermal gain of the fluid, thermal efficiency of the collector and performance of the water storage. The temperature of the absorber was higher in open sky conditions: 55,74ºC above it, decreasing in depth sequence of 52,1ºC and 49,3ºC. This temperatures of the absorber were 48,3ºC 46,2ºC and 44,6ºC respectively in a overcast days. The thermal gain of the working fluid in the absorber was decreasing with increasing length of the conductor: the gain was higher in summer and open sky days, reaching a maximum temperature of 52.7 ºC, and lowest in winter cloudy days, reaching a maximum temperature of 28.5 ºC. The collector thermal efficiency was higher in open sky days: 71.4% in summer and 74% in winter. The warm water storage system had excellent keeping temperature performance with 10% loss in the final water temperature
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Laakso, Merja. "Clean and Affordable Energy for Heating Water - Impacts and Feasibility of Solar Water Heaters in Lwandle, Cape Town." Thesis, Stockholms universitet, Kulturgeografiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-58353.
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In Cape Town, South Africa, households' acces to modern and clean energy services needs to be increased. However, use of coal-powered electricity stresses the environment and power cuts create an urgent need to reduce the demand. Solar water heaters (SWH) could enable increasing access and affordability of energy services in the townships without stressing the environment or increasing the demand for coal-powered electricity. However, it is an expensive solution and the majority of the city-level efforts still target the high-consuming households. The benefits for the poor households from using a SWH could though outweigh the high capital investements and meet the needs of the city's environmental management. The results from this study of 20 households showed that by having an affordable, clean and reliable source of energy for heating water, households were able to use more warm water for bathing and reduce their use of electricity and paraffin. This resulted in improvements in health and quality of life. Also, households' general spending on energy was reduced, which for some enabled an increase in income-generating activities. The use of solar-heated showers was found to be restricted by the issue of sharing and it is argued that the benefits would be greater if each households had their own solar water heater. The estimated increase in water use might raise questions of the solution's future feasibility. Despite this, it can be argued that the changes in the households' energy and water use are likely to result in significant improvements in the households' well-being which could also benefit the city as a whole.
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Kubátová, Anna. "Heating of building with almost zero energy consumption." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225687.
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The aim of the thesis is to model energetic needs for heating and temperatures progress in the building with almost zero energy consumption. The part of the work is the economical and energetic comparison. Proposed systems are based on a knowledge of active houses.
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Quinlan, Patrick Duane. "The development of a novel integrated collector storage solar water heater (ICSSWH) using phase change materials and partial evacuation." Thesis, Ulster University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.536464.
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The Integrated Collector Storage Solar Water Heater (ICSSWH) suffers significant ambient heat loss, especially during night-time and non-collection periods, due to its combined collection and storage function. A novel ICSSWH a Double Vessel Integrated Collector Storage (DVICS) comprised of two vertical concentric metal cylinders, with the resulting annulus filled with a Phase Change Material (PCM) and partial vacuum pressure, was designed to reduce thermal storage losses without compromising energy collection. The DVICS evolved through the development of 6 fabricated prototypes, including novel pockets and cowl configurations in the annulus, a polytetrafluoroethylene (PTFE) thermal break between the inner and outer vessel, elongation of the pockets to increase heat transfer to the PCM, aluminium vessel construction, differing water return arrangements, solar collection improvements to the vessel geometry, optimised pocket locations and transparent covers with insulation. The different DVICS designs were studied experimentally using thermal simulation, solar simulation and outdoor conditions at two European locations. The highest instantaneous collection efficiency was 43% and the lowest thermal losses coefficient was 0.98 Wm-2K-1. The heat transfer mechanisms were modelled using thermal resistance networks and dimensionless analysis. In addition the practical, environmental and economic considerations are presented.
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Yannakis, Nicholas Brian. "Economic optimisation of domestic solar hot water for the commercial market using consol evacuator tube panels in Christchurch, New Zealand." Thesis, University of Canterbury. Mechanical, 2012. http://hdl.handle.net/10092/10196.
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Domestic solar hot water is becoming a more common technology used specifically with the residential market of New Zealand. Recently domestic solar hot water systems have been economically identified as an option in commercial applications. Commercial building owners in the corporate world generally base decisions on economic reasons, therefore this research investigates the need to economically optimise the size of domestic solar hot water systems for eight separate commercial applications within Christchurch. All modelling has been completed using Consol’s heat pipe evacuator tube panels orientated North at an angle of 45 degrees.
The TRNSYS simulation program is utilised to model the domestic solar hot water system in the eight commercial applications. Each commercial application has a unique domestic hot water load profile. The heat pipe evacuated tube is locally available from Consol New Zealand Limited. A common proportional relationship was utilised to define the relationship between the size of the storage tank and area of solar panels, which enables a range of domestic solar hot water system sizes to be used in the simulations.
A proportional relationship is identified to economically optimise the size of commercial domestic solar hot water systems in Christchurch. This proportional relationship enables engineers and designers of commercial domestic hot water systems to confidently implement domestic solar hot water system designs. This provides an economically optimal solution in regards to the size of the solar component that should be installed during the rebuild of Christchurch.
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Mohan, Gowtham. "Novel Solar thermal polygeneration system for sustainable production of cooling, clean water and domestic hot water in UAE." Thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-152608.
Full text
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Dall'Antonia, Junior Luiz Carlos 1966. "Coletor solar alternativo de concreto para aquecimento de água em aplicações agrícolas e agroindustriais /." Botucatu : [s.n.], 2011. http://hdl.handle.net/11449/90488.
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Orientador: João Francisco EscobedoBanca: Eduardo Nardini Gomes
Banca: Alexandre Dal Pai
Resumo: O presente trabalho descreve a construção de um coletor solar alternativo de concreto de tração simples (areia, cimento e pedra), para aplicações agrícolas e agroindustriais. o coletor é constituído de uma área de absorção 51 m2 com 470m de mangueira de polietileno para o aquecimento da água, e o armazenador da água aquecida. O sistema coletor e armazenador foi submetido a testes experimentais onde foram determinados para as estações verão e inverno, e sob três coberturas de céu aberto, parcialmente nublada e nublada: as temperatura do absorvedor em três profundidades; ganho térmico do fluido; rendimento térmico do coletor, e desempenho do armazenador. Os resultados mostram que a temperatura do absorvedor foi maior na cobertura de céu aberto, decrescendo em seqüência de profundidade 55,74ºC, 52,10C e 49,30C respectivamente, e foi menor na cobertura de céu nublado, 48,30C, 46,20C e 44,60C respectivamente; o ganho térmico do fluido de trabalho no absorvedor foi decrescente em função do aumento comprimento do condutor: o ganho foi maior no verão e em dias de céu aberto, atingindo a temperatura máxima de 52,70C, e foi menor no inverno, em dias céu nublado, atingindo a temperatura máxima de 28,50C; o rendimento térmico do coletor foi maior em dia de céu aberto: no verão 71,4% e inverno 74%; o sistema armazenador térmico, mostrou ótimo desempenho na conservação da temperatura do fluido de trabalho. Nos dias estudados houve uma redução de 10% na temperatura final da água aquecida
Abstract: This paper describes the construction of an alternative sidewalk-type solar collector made of concrete (sand, cement and stone), for agriculture and agribusiness uses. The collector consists of an absorption area of 51 m2 with 470m polyethylene tubing for water heating, and a storage for warm water. The collector and storage systems were subjected to experimental tests which were determined for summer and winter, three sky conditions: open skies, partly cloudy and overcast; three depths temperature in the absorber; thermal gain of the fluid, thermal efficiency of the collector and performance of the water storage. The temperature of the absorber was higher in open sky conditions: 55,74ºC above it, decreasing in depth sequence of 52,1ºC and 49,3ºC. This temperatures of the absorber were 48,3ºC 46,2ºC and 44,6ºC respectively in a overcast days. The thermal gain of the working fluid in the absorber was decreasing with increasing length of the conductor: the gain was higher in summer and open sky days, reaching a maximum temperature of 52.7 ºC, and lowest in winter cloudy days, reaching a maximum temperature of 28.5 ºC. The collector thermal efficiency was higher in open sky days: 71.4% in summer and 74% in winter. The warm water storage system had excellent keeping temperature performance with 10% loss in the final water temperature
Mestre
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Huang, Chung-Kwei, and 黃重魁. "A Study on the Domestic Solar Water Heater by POE." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/sep6p7.
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碩士國立成功大學
建築學系碩博士班
90
Solar water heater has been promoted in Taiwan for a period of time. Although the installation is getting popular, some users and scholars still have negative opinions about this equipment. This research tried to investigate the benefit of solar water heater by P.O.E., and find out the power consumption factor about supplementary electric heater. Also, to give suggestions on the installation, usage and maintenance of this equipment. The investigations proceeded in two ways. First, survey the power consumption and benefit of this equipment by monitoring and on-site observation, and check if there are improper installation, usage and maintenance. Second, evaluate the hot water supply situation and installation of this equipment from questionnaires, and see if users understand and maintain this equipment properly. The result from monitoring investigations showed that even in the season of autumn and winter with less sunshine, solar water heater still reach ideal benefit of economy and energy. However, without proper installation and usage, it could cost and waste energy more than gas water heater. According to the result of investigations on 20 users, the power consumption of supplementary electric heater per cubic meter of hot water is relative to the pitch angle of the absorber plates, numerical V/A, and the setting habit of control device for supplementary electric heater. The cases of lower pitch angle or higher V/A had high power consumption per unit of hot water. In order to avoid power waste of supplementary electric heater caused by producing too much hot water than needed, set the temperature of hot water under 60℃ and the heating time under 5hrs per day with proper maintenance. Most locations of the control device on solar water heater are not convenient for users; also the space and facilities for maintenance are not good enough. Therefore, the installation should locate the control device properly for more convenient use, and make sure enough space and facilities for maintenance. Most users are not aware of control device or rarely use it, and only very few users maintain solar water heater periodically. Therefore, to educate users and advocate proper usage and maintenance will gain best benefit from solar water heater.
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"Performance Analysis of Solar Assisted Domestic Hot Water System." Master's thesis, 2016. http://hdl.handle.net/2286/R.I.38564.
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abstract: Testing was conducted for a solar assisted water heater and conventional all electric water heater for the purpose of investigating the advantages of utilizing solar energy to heat up water. The testing conducted simulated a four person household living in the Phoenix, Arizona region. With sensors and a weather station, data was gathered and analyzed for the water heaters. Performance patterns were observed that correlated to ambient conditions and functionality of the solar assisted water heater. This helped better understand how the solar water heater functioned and how it may continue to function. The testing for the solar assisted water heater was replicated with the all-electric water heater. One to one analyzes was conducted for comparison. The efficiency and advantages were displayed by the solar assisted water heater having a 61% efficiency. Performance parameters were calculated for the solar assisted water heater and it showed how accurate certified standards are. The results showed 8% difference in performance, but differed in energy savings. This further displayed the effects of uncontrollable ambient conditions and the effects of different testing conditions.Dissertation/Thesis
Masters Thesis Engineering 2016
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ELLIOTT, BRYN DAVIS. "Evaluation of an Indirect Solar Assisted Heat Pump Water Heater in the Canadian Environment." Thesis, 2012. http://hdl.handle.net/1974/6939.
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Solar Domestic Hot Water systems and air-source heat pumps offer the potential for energy savings in residential hot water production, however their performance is limited in cold climates, where the low ambient temperature reduces the collector efficiency or the heat pump coefficient of performance. Combining these systems into a Solar-Assisted Heat Pump can alleviate these limitations by reducing the required collector temperature and by providing an increased heat pump evaporator temperature.
This study is a continuation of the development of an Indirect Solar-Assisted Heat Pump undertaken at the Queen’s University Solar Calorimetry Laboratory. Previously, a numerical study compared its performance to existing technology, and based upon this feasibility analysis, a prototype was constructed for controlled laboratory tests using simulated solar input. In the current study, the prototype was modified to include a novel hybrid collector such that its performance under actual weather conditions throughout the year could be assessed.
On sunny days, the system experienced daily averaged collector efficiencies between 0.47 and 0.88, depending on the flow rate and season. Averaged heat pump coefficients of performance of 2.54 to 3.13 were observed. Overcast days experienced reduced coefficients of performance, between 2.24 and 2.44. However, on overcast days, upwards of 76% of the collected energy gain was from convection with the surroundings.
Based upon these experimental results, a model for the hybrid collector was developed. Annual simulations of the system were conducted to compare the performance of the solar heat pump system when fitted with the hybrid collector relative to cases with more conventional glazed and unglazed collectors commonly used in solar thermal systems. Results were produced for three Canadian cities: Toronto, Vancouver and Winnipeg. The heat pump with the hybrid collector outperformed the other collectors in the Toronto climate, with a free energy ratio of 0.548. Adding a thermally controlled valve to the hybrid collector was proposed to further increase the annual free energy ratio, and was shown to perform best in all three cities, with free energy ratios of 0.558, 0.576 and 0.559 for Toronto, Vancouver and Winnipeg, respectively. It is proposed that additional improvements could be achieved by allowing the collectors to deliver heat directly to the storage tank, by circumventing the heat pump if the conditions were favorable.Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2012-01-06 13:44:41.77
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Cheng, Kai-Wen, and 鄭凱文. "The analysis of energy consumption factors of Solar Domestic Hot Water System with a auxiliary heater." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/07432261095748616544.
Full textAbstract:
碩士國立成功大學
建築學系碩博士班
92
The research of SDHWS (Solar Domestic Hot Water System) by P.O.E shows that the energy consumption only 30％ are less than traditional gas heater，and 15％ are bigger than it. Only half of SDHWS can approach predicted profit. The group of max energy consumption are higher than the group of minimum energy consumption 6.8 times，the group of median energy consumption 3.5 times. It is not sure that SDHWS can truly save energy. Therefore, this study are focus on use behavior, climate and heating set of SDHWS, and following the result of research, put forward a proposal of main factors of energy consumption of SDHW. ◆Goal （1）To analyze the hot water use behavior and volume of SDHWS. （2）To put forward a proposal of main influence factors of energy consumption of SDHW. （3）To put forward a proposal of main influence factors of significant energy consumption pattern of SDHWS. ◆Methods This study use auto-monitor to record the volume of hot water use, energy, value of input-water temperature and output-temperature. The analyzing process use software of statistic, SPSS and Statistica, to analyze the factors of energy consumption. Use methods including Auto Regression, Factor Analysis, Cluster Analysis and MAOVA. ◆Result （1）The correlation between daily hot water use behavior and climate is not much：Only average hot water of each switch has minus correlation with outdoor temperature. （2）Use behavior of hot water doesn’t concern with energy consumption：In use behavior of hot water, only the rate of hot water use volume divided to storage tank volume and heating tank volume relate with energy consumption. （3）The heating time can effect energy consumption factors：When heating time under 3 hours, main factors of energy consumption are the rate of W/S and W/H in daytime and the rate of W/H in heating period. When heating time over 3 hours, the rate of S/H is main factor of energy consumption. （4）Different heating time should notice that the SDHWS can be suitable：If SDHWS is one storage tank and heater inbuilt, the heating time should under 3 hours. If SDHWS is multi-storage tank and a single heating tank, the heating time can over 3 hours but the rate of S/H must over two. （5）The setting of heater temperature batter less than 55℃：If temperature is between 50~55℃,energy consumption between 0.5~2.5Kwh；over 60℃, energy consumption bigger than 2.5Kwh.
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Dennis, Michael Kenneth. "Active control of split system domestic solar water heaters." Phd thesis, 2004. http://hdl.handle.net/1885/10734.
Full textAbstract:
Solar water heaters have the potential to make large savings in greenhouse gas
emissions in Australia. Long financial payback periods are the main reason that
uptake of solar water heating is not more significant. This thesis investigates
the potential improvement in performance of split-system solar water heaters
by the addition of an active control system.
This work builds upon "low flow" collector circulation theory and addresses the
poor control available from the storage tank thermostat. Modelling suggests
that the thermal efficiency of the water heater can be improved by about 25°/o,
primarily through reduction of tank standing losses, if the thermostat is
replaced by a smart controller. Auxiliary energy consumption is reduced
proportionally. If realisable, these savings recover the capital cost of the
additional controller in several years. The consumer will benefit from further
savings in auxiliary energy consumption over the life of the system and so the
payback will be more attractive.
The active control strategy is based upon predicting and controlling the energy
content of the storage tank. The control strategy is energy tariff sensitive and
may be set by the householder to behave in an energy efficient or a cost
effective manner. A number of technologies and design improvements
regarding forecasting of the energy supply and demand were also developed in
this work.
The auxiliary heater was moved outside of the tank and placed in series with
the solar collector via a switching valve arrangement. The collector circulation
pump was also used to circulate water through the auxiliary heater effectively
providing a variable volume, variable temperature thermostat. A new variable
power pump controller was developed for the existing circulation pump to allow
fine temperature control of water returning from both the auxiliary and solar
heat sources so that disruption to thermal stratification in the tank was
minimised. The predictive performance of the collector could then be decoupled
from the state of the tank. This thesis explores a practical implementation of the active control strategy and provides an insight into the actual performance
and areas of sensitivity of the technology.
The proposed design changes require more thorough validation including field
trials to evaluate the load learning algorithms. Performance of the active
controller would be improved if the heating circuit intake position could be
actuated vertically within the tank or if hot and cold water could be fully
separated in the tank.
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BRIDGEMAN, Andrew George. "Experimental Analysis of an Indirect Solar Assisted Heat Pump for Domestic Water Heating." Thesis, 2010. http://hdl.handle.net/1974/6129.
Full textAbstract:
Due to rising energy costs and increasing environmental awareness, various methods of energy conservation are being investigated. In the residential sector, both solar and heat pump systems have been extensively tested. Recently, combinations of solar and heat pump systems have been developed for both space heating and water heating. These systems have the capability to provide better performances than either of the systems operating on their own. The solar collector benefits from a lower fluid (glycol) inlet temperature which increases efficiencies, and the heat pump benefits from higher evaporator temperatures due to the additional solar energy collected.
For this study, a prototype of an Indirect-Solar Assisted Heat Pump for use in the Canadian environment was constructed, instrumented and tested. Controlled, constant temperature tests, as well as solar profile tests were conducted and the heat transfer rates, natural convection flow rate, and heat pump coefficient of performance (COP) were calculated. These values were then compared to simulation results based on a model developed in a previous feasibility study. The experimental COPs calculated ranged from 2.3 to 3.3 throughout the full range of tests which were conducted with supply temperatures ranging from 0°C – 40°C. The simulated results consistently overestimated the experimental results by between 12% - 15%. New empirical heat exchanger relationships were developed for the model bringing the simulated results within 5% of the experimental results for tests run at glycol flow rates of 77 and 154 kg/hr. These relationships were used to refine the model, and produce updated annual performance values in the TRNSYS simulation software. Updated results showed a 5% drop in the annual free energy ratio in Toronto from 57% to 52%, but further optimization of the system using the TRNSYS software package improved annual results up to 56%.
For the purposes of the study, a solar assisted heat pump prototype was constructed and tested successfully within the laboratory environment. Results showed that the system has a strong market potential, especially in regions without a strong solar resource. Based on these results further research is recommended, continuing with a full year outdoor test using unglazed solar collectors.Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2010-10-12 18:53:01.189
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Li, Bo. "High resolution time-series modeling of domestic hot water heating systems." Thesis, 2011. http://hdl.handle.net/1828/3611.
Full textAbstract:
This thesis evaluates domestic water heating systems in conjunction with energy saving technologies such as solar water heating, drain water heat recovery, and heat pump water heating. Five dynamic models are developed using Matlab Simulink® with a time-step of one minute. Using minute resolution hot water flow, hourly solar radiation data and ambient temperature, the performance of various configurations are assessed when operating in Victoria, Kamloops, and Williams Lake, B.C. Twelve different demand profiles on a summer day and winter day are simulated. Some specific metrics, such as conventional energy consumption, system energy factor, and equivalent CO2 emissions are used as the basis of evaluating the system efficiency.
Results indicate the potential improvements in system performance over a conventional domestic water heating system in lower conventional energy consumption and lower CO2 emissions when applying any one of the three energy saving technologies mentioned above. For example, on a representative summer day (Day 228) in Victoria with a load profile of a low-use two-person family on a weekday, the system‟s energy factor can be improved from 0.50 to up to
2.84, and the corresponding conventional energy consumption and the CO2 emissions decrease from 9.86 kwh to 1.67 kwh, and 1.77 kg/day to 0.06 kg/day, respectively depending on which energy saving technology is applied.
The modeling tool developed in this research can be used to guide the design of domestic water heating systems with various system configurations.Graduate
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Sterling, Scott Joseph. "Feasibility Analysis of Two Indirect Heat Pump Assisted Solar Domestic Hot Water Systems." Thesis, 2011. http://hdl.handle.net/10012/5759.
Full textAbstract:
This thesis is an analysis of the simulated performance of two indirect heat pump assisted solar domestic hot water (i-HPASDHW) systems compared to two base systems: an electric domestic hot water (DHW) system and a traditional solar domestic hot water (SDHW) system. In this study, the four systems of interest were modeled in the TRNSYS software and simulated for a year in order to compare their performances. All of the systems had the same load profile and aimed to deliver domestic hot water at a constant temperature. This insured that each system delivered approximately the same amount of energy for the simulated period, thereby creating a common basis for comparison.
The heat pump was introduced into the system configuration in an attempt to further improve the performance. Theoretically, the heat pump should send colder fluid to the collector which will extend the solar collection periods, both daily and seasonally when compared to the traditional SDHW system, as well as increase the efficiency of the collector. This will help to reduce the reliance on the electric auxiliary heaters and thus decrease the total electricity consumption.
Both i-HPASDHW systems considered for this thesis collected more solar energy over the course of the simulated year compared to the base traditional SDHW system. They also consumed less electricity than the two base systems, which directly correlated to lower annual operating costs.
It was concluded that the two i-HPASDHW systems analyzed in this study proved to be feasible configurations that performed more efficiently than the two base systems under the simulation conditions. However, it is important to understand that the results presented apply to the specific configurations. While the potential has been shown, prototypes must be built and tested with properly sized equipment for specific applications to get an accurate idea of the potential benefits. Also, equipment costs must be considered to determine payback periods for each system.
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Alsagheer, Fozi. "An Investigation of Methods to Enhance Stratification in Solar Domestic Hot Water Tanks." 2011. http://hdl.handle.net/10222/13332.
Full textAbstract:
Solar domestic hot water (SDHW) systems collect energy with a solar collector, transfer the energy to the water through a heat exchanger, and store it in a storage tank. The water in the tank should be thermally stratified to the highest possible degree to maximize system efficiency because a stratified tank has higher availability than a mixed tank temperature. The objective of this research is to develop a manifold that will enhance thermal stratification in the SDHW tank.
In this work a new immersion shell-and-coil heat exchanger with a perforated manifold that extends from the heat exchanger to the top of the tank was used to enhance the thermal stratification. The purpose of the perforated manifold is to deliver the water heated by the heat exchanger to the tank at the level where the temperature of the water in the tank matches the temperature of the heated water, thereby enhancing stratification.
The effectiveness of the perforated manifold was determined experimentally. An experimental set-up was designed and constructed. The experimental results were analyzed for each manifold design then compared to determine the most effective manifold. The experimental work included testing and comparing different manifold designs. To simulate an actual system, experiments were conducted on three initial tank conditions, namely cold, hot, and mixed tank conditions.
The thermal performance of the system in terms of tank availability and entropy, maximum tank temperature, and thermal stratification were studied. A method to determine and design a perforated manifold that works with the standard Canadian SDHW system was established and evaluated experimentally. An availability analysis approach was developed to evaluate the thermal performance of manifolds, which have been operated at different times of the year.
Theoretically, gradually increasing the diameter of the holes in the manifold from the bottom into the top should reduce the unwanted flow of cold water from the bottom of the tank to the manifold and enhance the thermal performance of the manifold. However, the experimental did not confirm this.
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Wagar, William Robert. "Simulation and Validation of a Single Tank Heat Pump Assisted Solar Domestic Water Heating System." Thesis, 2013. http://hdl.handle.net/10012/7347.
Full textAbstract:
This thesis is a study of an indirect heat pump assisted solar domestic hot water (I-HPASDHW) system, where the investigated configuration is called the Dual Side I-HPASDHW system. The study outlines the development of an Experimental Test Unit (ETU), and focuses on the experimental validation of TRNSYS models. Shortcomings of the system design realized throughout the validation process, as well as weaknesses in the control schemes used to operate the system are also provided.
A description of the Dual Side I-HPASDHW system is provided along with the design intent of the system. The corresponding ETU is presented in detail to provide a comprehensive understanding of the ETU’s simulation capabilities. Components of the ETU, such as the heat pump, heat exchanger, and domestic hot water (DHW) tank are characterized in order to provide input data for built-in TRNSYS models, and to develop custom TRNSYS models for the heat pump and heat exchanger. Heat exchanger performance is modelled with a linear correlation, while the heat pump performance is mapped by applying experimental data to three-dimensional surface fitting software.
For the purpose of validation, the ETU is used to simulate the performance of the Dual Side I-HPASDHW system under a realistic control scheme. Four full day tests are conducted using data from a fall, winter, and summer day. The full day summer test is repeated with and without electrical backup heating. The TRNSYS model of the Dual Side system is tuned in order to provide the closest match possible between the computer simulation and the measured performance of the ETU.
Experimental tests were compared with TRNSYS simulations to reveal some disparity in the results. The majority of simulation error was attributed to inaccuracy in modeling DHW tank temperatures and water circulation patterns. The disparity created by the DHW tank model only resulted in substantial performance deviation when inaccurate DHW temperatures were used directly for vital control decisions.
Conclusions were drawn suggesting that the TRNSYS model of the ETU was valid for a majority of operating conditions, often matching experimental tests well within experimental uncertainty. Caution was recommended towards the use of the developed TRNSYS model, where techniques were recommended for tracking and minimizing substantial simulation errors. Several key performance issues affecting the Dual Side I-HPASDHW system were targeted with recommendations for design and control alterations, along with future improvement and optimization studies.
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Avina, John. "The modeling of a natural convection heat exchanger in a solar domestic hot water system." 1995. http://catalog.hathitrust.org/api/volumes/oclc/33083188.html.
Full textAbstract:
Thesis (M.S.)--University of Wisconsin--Madison, 1995.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 233-234).
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Murray, Robynne. "SIMULTANEOUS CHARGING AND DISCHARGING OF A LATENT HEAT ENERGY STORAGE SYSTEM FOR USE WITH SOLAR DOMESTIC HOT WATER." 2012. http://hdl.handle.net/10222/15169.
Full textAbstract:
Sensible energy storage for solar domestic hot water (SDHW) systems is space consuming and heavy. Latent heat energy storage systems (LHESSs) offer a solution to this problem. However, the functionality of a LHESS during simultaneous charging/discharging, an operating mode encountered when used with a SDHW, had not been studied experimentally.
A small scale vertical cylindrical LHESS, with dodecanoic acid as the phase change material (PCM), was studied during separate and simultaneous charging/discharging. Natural convection was found to have a strong influence during melting, but not during solidification. During simultaneous operation heat transfer was limited by the high thermal resistance of the solid PCM. However, when the PCM was melted, direct heat transfer occurred between the hot and cold heat transfer fluids, indicating the significance of the PCM phase on heat transfer in the system. The results of this research will lead to more optimally designed LHESS for use with SDHW.
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Gharbia, Ibrahim. "A Theoretical and Experimental Investigation of a Shell-and-Coil Heat Exchanger for a Solar Domestic Hot Water System." 2010. http://hdl.handle.net/10222/13067.
Full textAbstract:
Solar energy is an important form of renewable energy that can be used as an alternative to fossil fuels. It can be used to produce electricity or to provide heat. One particular application is using solar energy for a domestic hot water system.
The purpose of this research is to improve the thermal performance of a solar domestic hot water (SDHW) system. Experimental research was conducted to study the thermal performance of a shell-and-3coil heat exchanger and a shell-and-4coil heat exchanger using either water or glycol as working fluids on the tube side.
An experimental set-up simulating a SDHW system was designed and constructed. The set-up contained a 270 L storage tank, a shell-and-three coil heat exchanger or a shell-and-four coil heat exchanger, and electrical heaters to simulate the solar collector. At the inlets and outlets of the storage tank and the heat exchanger the temperatures, pressures, and flow rates were measured to determine the thermal performance. The results from the experiment tests were analyzed in terms of the overall heat transfer coefficient product (UA) and the pressure drop (?P) between the inlet and outlet of the heat exchanger.
The UA value of the shell-and-4coil heat exchanger was higher than the UA value of the shell-and-3coil heat exchanger. For example, at a heat transfer rate of 2000 W for water, the UA values were 240 W/K and 270 W/K for the shell-and-3coil heat exchanger and the shell-and-4coil heat exchanger, respectively. With respect to glycol, at a heat transfer rate of 2000 W the UA values were 197 W/K and 215 W/K for shell-and-3coil, and shell-and-4coil heat exchanger, respectively. The degradation of the thermal performance of the shell-and-3coil was offset by benefits, such as reduction in mass, volume, labor cost and the final cost. A reasonable agreement between theoretical and experimental results in terms of the UA value was observed.
The thermal performance of each coil in both heat exchangers was below that predicted by the relevant heat transfer correlations. A performance factor was calculated for each coil. For both glycol and water, and both heat exchangers, the performance factors for the inner most and outer most coils were 0.70 and 0.53, respectively. However, there is a slight difference in the performance factors of coils between the inner most and the outer most coils for the 3-coil and 4-coil heat exchangers. For these coils the performance factors varied from 0.55 to 0.67.
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Baum, Matthias. "Untersuchungen zur Energiegewinnung mit einem Solardach-Luft-Kollektor." Doctoral thesis, 2010. http://hdl.handle.net/11858/00-1735-0000-0006-AB24-C.
Full text
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Morais, Vítor Filipe Alves. "Domestic Heat-Pump Water Heater Smart Controller." Master's thesis, 2015. https://repositorio-aberto.up.pt/handle/10216/88909.
Full text
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Morais, Vítor Filipe Alves. "Domestic Heat-Pump Water Heater Smart Controller." Dissertação, 2015. https://repositorio-aberto.up.pt/handle/10216/88909.
Full text
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Ratzmann, Paul M. "Analysis of a large scale solar water heater." 1992. http://catalog.hathitrust.org/api/volumes/oclc/26108040.html.
Full textAbstract:
Thesis (M.S.)--University of Wisconsin--Madison, 1992.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 95-96).