Academic literature on the topic 'District heating pipes'
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Journal articles on the topic "District heating pipes"
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Kuprys, Algirdas, and Ramūnas Gatautis. "COMPARISON REFURBISHMENT MODELS OF DISTRICT HEATING NETWORKS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 20, no. 1 (October 24, 2013): 11–20. http://dx.doi.org/10.3846/13923730.2013.812576.
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The renovation of multi-storey residential buildings reduces heat consumption intensity and decreases heat demand, which may have a harmful effect on a district heating supply system. The paper analyses the heat loss change in four district heating distribution networks (DHNs) of Kaunas at the various scenarios of buildings and DHN renovation stages. A bundle of genetic algorithm software package was used to carry out the districts’ distribution network hydraulic calculations in the case of building renovation without changing the hydrodynamic and network routes. The experimental data were used to calculate heat loss for old and new pipes. The computer data of networks used to summarise the cost of DHN then for the renovation of buildings as well as for renovation progress will go evenly with DHN refurbishment. Network optimization results were summarised by functional dependence. The comparison of the projects’ efficiency was analysed in the following cases: the diameters of pipes of DHN were not changed, new diameters of pipes were integrated partly after partial residential buildings renovation and after a complete renovation of residential building and optimisation of pipeline diameters. The efficiency of separate guidelines of the DHN refurbishment project was summarised by performing sensitivity analysis.
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Leuteritz, Andreas, Klaus-Dieter Döring, Thomas Lampke, and Ines Kuehnert. "Accelerated ageing of plastic jacket pipes for district heating." Polymer Testing 51 (May 2016): 142–47. http://dx.doi.org/10.1016/j.polymertesting.2016.03.012.
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B�hm, Benny. "On transient heat losses from buried district heating pipes." International Journal of Energy Research 24, no. 15 (2000): 1311–34. http://dx.doi.org/10.1002/1099-114x(200012)24:15<1311::aid-er648>3.0.co;2-q.
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Weidlich, Ingo, Marcus Illguth, and Gersena Banushi. "Reserves in axial shear strength of district heating pipes." Energy Procedia 147 (August 2018): 78–85. http://dx.doi.org/10.1016/j.egypro.2018.07.037.
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Wolfrum, Dominik, and Thomas Neidhart. "District heating pipes buried in Temporarily Flowable Backfill Materials." Energy Procedia 149 (September 2018): 170–78. http://dx.doi.org/10.1016/j.egypro.2018.08.181.
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Khosravi, Milad, and Ahmad Arabkoohsar. "Thermal-Hydraulic Performance Analysis of Twin-Pipes for Various Future District Heating Schemes." Energies 12, no. 7 (April 4, 2019): 1299. http://dx.doi.org/10.3390/en12071299.
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Future energy systems will come with a 100% share of renewable energy and high integration of energy systems. District heating and cooling systems will be undeniable parts of the future energy systems, as they pave the bed for high-efficiency, low cost, and clean production. District heating systems may come into a wide range of designs in the future. Currently, most of the world’s district heating systems are based on the third generation design while everything in this framework is on the verge of a transition to the fourth generation. A large number of technologies for the future district heating systems has been proposed so far, among which low-, ultralow- and variable-temperature systems seem more of qualification. This study employs computational fluid dynamics to make a comprehensive examination of the compatibility of regular twin-pipes with various potential district heating schemes for future energy systems. The results show that both low- and ultralow-temperature systems could efficiently use regular twin-pipes commonly used in the third generation district heating systems, though the insulation of the pipe could be proportionally strengthened based on a techno-economic trade-off. In contrast, the results show that the thermal inertia of the pipe does not allow the variable-temperature district heating system to effectively operate when the transmission pipeline is longer than a limited length. Therefore, a regular heat distribution network may not be an appropriate host for a variable-temperature district heating scheme unless decentralized heat production units come into service.
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Mangs, Sara, Morgan Fröling, Olle Ramnäs, and Ulf Jarfelt. "Transport of 1,1,1,3,3-Pentafluorobutane (HFC-365mfc) in Rigid Polyurethane Foam and Polyethylene." Cellular Polymers 21, no. 3 (May 2002): 155–64. http://dx.doi.org/10.1177/026248930202100301.
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This study focuses on the mass transfer properties of 1,1,1,3,3-pentafluorobutane (HFC-365mfc) in the insulating system used in most district heating pipes produced today, namely rigid polyurethane (PUR) foam with a protective layer of polyethylene (HDPE). The solubility, permeability and diffusion coefficients for HFC-365mfc in PUR foam and HDPE have been determined. The coefficients for HFC-365mfc in PUR foam are very similar to those of cyclopentane, currently the most common blowing agent in PUR foams used for district heating pipes in Europe. The polyethylene casing is a better diffusion barrier for HFC-365mfc than it is for cyclopentane. However, the main mass transfer resistance of HFC-365mfc in a district heating pipe is found in the PUR foam.
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Babus'Haq, R. F., S. D. Probert, and M. J. Shilston. "Steady State Heat Losses from Horizontal Pipes in an Air-Filled Rectangular Concrete Duct." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 199, no. 3 (July 1985): 203–13. http://dx.doi.org/10.1243/pime_proc_1985_199_115_02.
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Factors influencing the steady state heat loss behaviours of horizontal ‘supply’ and ‘return’ hot-water pipes, within an atmospheric pressure air-filled, relatively cold, horizontal rectangular trench, are considered. An experimental investigation concerning the effects of the displacement ratios for the two pipes revealed the optimal configuration, that is one which achieves a minimum steady state rate of heat loss from the supply pipe. For one set of temperatures for the pipes and trench walls, the optimal configuration of the supply and return pipes occurred at displacement ratios of +0.70 and −0.05, that is with the supply pipe in the upper region of the cavity and the return pipe vertically below it, the pipes being equidistant from the vertical walls of the trench. This configuration is of significance with respect to achieving maximum energy thrift for district heating pipelines, because it differs radically from the ‘side-by-side’ arrangement of pipes conventionally adopted in district heating practice.
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Li, Zhen, Wei Wei Wang, and Hong Ming Sun. "Life Cycle Assessment of the District Heating Distribution System in China — Network Construction." Applied Mechanics and Materials 256-259 (December 2012): 2662–66. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.2662.
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In China, the environmental impact from the construction of the distribution system is seldom discussed. In this study, the environmental impact from construction of district pipes is considered. The purpose is to identify environmental significant parts in the construction of district pipes and to use the results in the actual projects including once more parts of the district distribution system have been investigated with LCA methodology.(Methods) Construction of district pipe networks according to the technical specification was studied. The total consumption of energy and materials was calculated based on budget norm for projects. The functional unit used in the study is construction of 100 metres of pipe system. The studied pipes are: pipe of the dimension DN100, DN200 (Seamless steel tubes) and DN500 (spirally welded steel tubes) .Urban environment surroundings were studied. A short description of the inventory, some inventory results and a life cycle impact assessment are presented. Based on the concept of the End-point damage weighting method, the total environment load is given.
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Dong, Yuan Yuan, Fei Wang, Yong Gang Lei, and Guo Wei Wang. "Equivalent Stress Cycles Based on District Heating Operation." Applied Mechanics and Materials 713-715 (January 2015): 295–99. http://dx.doi.org/10.4028/www.scientific.net/amm.713-715.295.
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We investigated supply water temperature of the district boiler between 2006 and 2014.And calculated the design life cycles of heating pipeline based on the district boiler as the heat source. Then superposed the number of the design life cycles caused by pipelines accidents and district boiler of the main trunk lines, distribution lines and subscriber connection line, we obtained the design life cycles of different heating pipes. This result can provide a basis for fatigue damage analysis of heating pipe fittings.
Dissertations / Theses on the topic "District heating pipes"
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Neale, Antony John. "Heat transfers from district heating pipes." Thesis, Cranfield University, 1987. http://dspace.lib.cranfield.ac.uk/handle/1826/4546.
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Experimental and numerical investigations were carried out on
air-filled cavities containing heated inner cylinders.
The effect of varying the position of radial spacers on a
single cylinder was studied. It was concluded that for central
positioning of the cylinder within the cavity. the rate of
heat-transfer was minimised at a radial spacer angle of 480
(measured from the vertically downwards radius vector). When
the cylinder was positioned at displacement ratio of 0.7, the
rate of heat-transfer was minimised at a corresponding spacer
angle of 520. The corresponding reductions in the total rate
of heat-transfer were found to be 25% and 31% less than that
obtained for the system with no spacers at a cylinder
displacement ratio of zero.
Following this research investigation, the behaviour of a
two-pipe arrangement, consisting of a hot supply and cooler
return pipe within a rectangular sectioned cavity, was
studied. Eccentric positioning of both supply and return pipes
showed that minimum rates of heat-transfer occur at supply and
return pipe displacement ratios of 0.45 and -0.33
respectively. This value of heat-transfer is approximately 20%
less than that obtained for a system where supply and return
pipe displacement ratios are 0.7 and zero respectively.
As experimental testing has proved to be excessively time
consuming (e. g. due to having to wait until a steady-state
ensued before measurments were taken) and laborious, a
finite-element numerical model was developed and used to
predict the heat-transfer between a heated inner cylinder and a
cooled outer square duct.
This study investigated eccentricity effects on the rate of
heat-transfer for different ratios of duct height to cylinder
radius. Solutions were obtained for Rayleigh numbers 1 to 300
and optimal pipe eccentricity for minimum heat-transfer was
predicted. These predictions were in good agreement with
previous experimental results.
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Reeve, Helen E. "A study of the thermal field surrounding buried district heating pipes." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10358.
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Traditional deep buried water and sewer services in northern communities can be prohibitively expensive due to deep frost penetration. Alternative municipal systems can also be uneconomic owing to cost-intensive freeze protection schemes. The integration of district heating (DH) systems with domestic services allows shallow burial of all services in a common trench by using the waste heat from the DH pipes as freeze protection for the nearby municipal lines, thus providing an economically attractive solution. A steady-state 2-dimensional numerical model, based on finite volume principles, was developed as a tool for the design of integrated services systems. The model can predict the thermal field surrounding any number of pipes in any configuration and under a wide variety of ground conditions. Insulation boards can be modeled in any configuration in the soil surrounding the pipes. The main grid system is a rectangular coordinate system with local embedded sub-grids in cylindrical coordinates inserted around each pipe to reflect the radial flow of heat in the vicinity of the pipes. This numerical model was tested and proved to be self-consistent. Predicted temperatures were compared with temperatures taken around experimental pipe loops. Two systems of pipe loops with different diameters were tested, each system having an insulation board placed directly above the pipes. The predicted temperatures agreed well with the experimental temperatures. Anomalies found were explained by settling of the sand and deficiencies in backfilling in the region of the pipes due to the proximity of the insulation board to the pipes. These effects were modeled by inserting a thin air gap around the pipes, resulting in closer agreement between predicted and experimental temperatures. The model was determined to be a valid tool for the design of integrated services systems.
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Pericault, Youen. "Shallow co-location of water, sewer and district heating pipes : Applicability in cold climate regions." Licentiate thesis, Luleå tekniska universitet, Arkitektur och vatten, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73137.
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Huber, Michael. "An experimental investigation of thermal effects on the axial resistance to relative ground movement of buried district heating pipes." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/48496.
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District heating (DH) systems are commonly used in urban areas to distribute thermal energy from central heat sources. Buried pipes, with a composite cross-sectional construction, are used to transport a heated medium, usually water. These pipes expand and contract radially and axially due to changing water temperatures, invoking soil-pipe interaction situations during operation, and potentially leading to significant pipeline material strains. Measures to account for these soil-pipe interactions are an important consideration and a significant cost factor when designing and installing robust and cost-effective DH pipe systems.
A series of full-scale tests were undertaken to provide experimental data on the axial and lateral soil resistance of DH pipes. An existing soil chamber that is part of the Advanced Soil Pipe Interaction Research™ (ASPIRe™) facility at the The University of British Columbia (UBC) was adapted to test full-size water-filled pipes. As a part of this project, a heating system was developed specifically to apply different heating histories to the water mass before the pipe is pulled. Strain gauges were mounted on the pipe at the soil interface to contribute to understanding the mechanisms involved in soil-pipe interaction.
It was shown that changes in the temperature of the water mass have a significant influence on axial pullout resistance of the DH pipe. After heating the water mass by ∆T = 50 °C, large-strain resistance increased by roughly 15 % compared to the control tests. Three full cooling and heating cycles reduced the axial soil resistance of the pipe, potentially due to an arching mechanism in the soil.
Considerable strain was measured at the soil-pipe interface both in axial and radial direction during heating of the water mass. Based on the development of strain with the heating history, it was inferred that the expansions at the pipe surface result from a combination of strains from both the steel pipe at the core and the high-density polyethylene (HDPE) cover. Consequently, DH pipes have to be treated as a complete system in combination with the surrounding soil mass in order to accurately model their mechanical behaviour under thermal load.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Behnam, Majd, and Axel Karlsson. "Värmeförluster i fjärrvärmerör : En granskning av värmeförluster i fjärrvärmerör." Thesis, KTH, Byggteknik och design, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215299.
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Den här examensarbete är en utredning av värmeförluster och ekonmiska besparingar av olika fjärrvärmerör. En fiktiv fjärrvärmeförläggning på 100m, för respektive dimension av fjärrvärmerör, har legat till grund för beräkningarna. Syftet är att få en klar bild på hur lönsamt det är att använda sig utav isoleringsserie 3 istället för isoleringsserie 2 alternativt dubbelrör med isoleringsserie 2 när förutsättningar tillåter detta.Resultaten visar att dubbelrör i mindre dimensioner har en lägreinvesteringskostnad, har lägre värmeförluster och ger en större vinst än vad enkelrör serie 2 och serie 3. För dubbelrör i större dimensioner så är investeringskostnaderna något högre men värmeförlusterna mycket lägre.I jämförelsen mellan serie 2 och serie 3 så är serie 3 lönsamt i båda fallen.Dessa resultat visar att det gynnar fjärrvärmenätägare i längden att använda sig utav en högre isoleringsserie alternativt dubbelrör.Examensarbetet har ej utrett miljöpåverkan av respektive rör, ej heller har kontirör undersökts.This thesis is an evaluation of heat losses and economical savings for different types of district heating pipes. Calculations have been based on a fictional district heating system with the length 100m, for each district heating pipe dimension. The cause is to get a clear image of how profitable it is to use a higher series of insulation alternatively using twin pipes when it’s possible.The results show that twin pipes in lower dimensions has a lower investment cost, less heat losses and is more profitable than insulation series 2 and series 3. When it comes to twin pipes with a higher dimension the investment cost is slightly higher than single pipe insulation series 3, though the heat losses are much lower.The comparison between series 2 and series 3 show that series 3 is more profitable in both cases.These results show that it’s profitable for the network owners in the long-term to use either a higher insulation series or twin pipes.No evaluation of neither the impact on the environment or district heating pipes with diffusion barrier, has been done.
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Oppelt, Thomas. "Modell zur Auslegung und Betriebsoptimierung von Nah- und Fernkältenetzen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-179211.
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Fernkälte bietet das Potenzial, wirtschaftlich und ökologisch vorteilhaft zur Deckung des stetig zunehmenden Klimakältebedarfs beizutragen. Im Rahmen dieser Arbeit wurde ein dynamisches thermohydraulisches Netzmodell „ISENA“ entwickelt, mit dem während der Planung und des Betriebs von Fernkältesystemen auftretende Fragen, beispielsweise in Bezug auf Wirtschaftlichkeit und Energieeffizienz, beantwortet werden können. Das Netzmodell setzt sich aus einem quasistationären hydraulischen Modell und einem instationären thermischen Modell zusammen, das auf der Verfolgung von Wasserpfropfen durch das gesamte Netz basiert (Lagrange-Ansatz). Mit diesem Modellierungsansatz können numerische Fehler sowie Bilanzungenauigkeiten vermieden werden, sodass sich eine höhere Ergebnisgüte im Vergleich zu bisher bekannten Netzmodellen erreichen lässt. Ebenfalls neu entwickelt wurde das Teilmodell zur Abbildung der Wärmeströme über die Wände unterirdischer Rohrpaare (Kälteverluste und -gewinne). Dieses Modell erlaubt die Bestimmung der instationären Rohrwand-Wärmeströme für wärmegedämmte unterirdische Rohrpaare, Rohrpaare mit gedämmtem Vor- und ungedämmtem Rücklauf sowie ungedämmte Rohrpaare. Anhand von Validierungs- und Verifikationsrechnungen wird gezeigt, dass ISENA verlässliche Ergebnisse liefert und für die praktische Anwendung geeignet ist. Abschließende Beispielrechnungen geben einen Einblick in die Untersuchungsmöglichkeiten, die das neue Modell bietet – unter anderem im Hinblick auf den Vergleich von Pumpenregelungsvarianten, den Einfluss von Rohrdämmung und Erdreicheigenschaften auf Kälteverluste und -gewinne sowie die Einbindung von Hochtemperatur-Kälteverbrauchern in den NetzrücklaufDistrict cooling can provide economic and ecological benefits while supplying the increasing cooling demand for air conditioning. In the present thesis, a dynamic thermo-hydraulic model “ISENA” is presented which may be used in order to answer questions arising during design and operation of district cooling networks—e. g., that are related to economic and energy efficiency. The network model consists of a quasi-static hydraulic module and a transient thermal module being based on the tracking of water segments through the entire network (Lagrangian method). With this approach, numerical errors and inaccuracies in the balance of conserved quantities could be avoided, which eventually leads to a better reliability of the results as compared to that obtained from other network models. Additionally, a new sub-model has been developed for predicting the transient heat flux through the walls of buried pipes in order to model thermal gains and losses. This model covers un-insulated, insulated and combinations of insulated as well as un-insulated pipes. Calculations performed for the purpose of validation and verification are presented in order to demonstrate that ISENA provides reliable results and hence is suitable for practical applications. Finally, example simulations show the various possibilities provided by the new model—for example, concerning the comparison of different strategies for pump control, the influence of pipe insulation and soil properties on thermal gains and losses as well as the connection of buildings equipped with high temperature cooling systems to the return line of the network
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Öman, Sandra. "Konstruktion av en nedsänkt värmeväxlare för nyttjande av lågvärdig värme vid urladdning av bergrum." Thesis, Luleå tekniska universitet, Energivetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79143.
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Behovet av att kunna lagra energi blir allt större och nödvändigare i takt med utvecklingen och användningen av de förnyelsebara energikällorna. Bergrumslagring är en beprövad metod som oftast används för att säsongslagra värme från fjärrvärme. Tidigare har ett examensarbete på PiteEnergi utförts med mål att undersöka om det är möjligt att lagra fjärrvärme från ett lågtempererat nät på Haraholmen i ett närliggande bergrum. Resultatet blev att det fanns goda förutsättningar men vid urladdning fanns en stor mängd energi fortfarande kvar i bergrummet. Detta arbete är en fortsättning på det, att undersöka om det är möjligt att nyttja även den lågvärdiga energin i bergrummet med en nedsänkt värmeväxlare. Den nedsänkta värmeväxlaren har i detta examensarbete konstruerats och resulterade i 3 mil långa stålrör, uppdelade i fem parallellkopplade värmeväxlare med ytterdiametern 89 mm. Den nedsänkta värmeväxlaren som i detta projekt är konstruerad har en återbetalningstid på 10 år och en livslängd på 30 år. Vinsten av investeringen skulle efter 30 år vara ungefär 30 miljoner kronor. Ungefär 1 GWh mer än tidigare är möjligt att årligen ta ut med en nedsänkt värmeväxlare, jämfört med en klassisk som endast nyttjar den högvärdiga energin i bergrumsvattnet som är tillräckligt varmt att köra direkt ut på fjärrvärmenätet.As the development and use of renewable energy sources grow, the need for energy storage is becoming increasingly important. Rock storage is a tried and tested method most commonly used to store seasonal heat from district heating. A previous degree project was carried out at PiteEnergi, with the aim of investigating whether it is possible to store district heating from a low-temperature grid at Haraholmen in an adjacent cavern. The conclusion was that there are good conditions for rock storage, but when discharging there were still a lot of energy left in the cavern. This degree project is a continuation of a previous work, to investigate the possibility of using a submerged heat exchanger to utilize even the low energy left in the underground caverns. The submerged heat exchanger has been designed in this thesis and resulted in 30 kilometre long steel pipes, divided into five parallel coupled heat exchangers with the outer diameter of 89 mm. The immersed heat exchanger constructed in this project has a payback time of 10 years and a life expectancy of 30 years. After 30 years, the profit from the investment would be about 30 million SEK. Compared to a classic heat exchanger, the submerged heat exchanger has the possibility of annually charging about 1 GWh more than before. This compared to a classic heat exchanger that only uses the high-quality energy from the water in the underground cavern that is hot enough to run directly to the district heating network.
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Fisco, Stefano. "Modelling of decentral DHW preparation in large multi-family buildings." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18295/.
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The works contributes to the need to design more efficient heating and domestic hot water preparation systems. Dynamic building and simulation plays an important role in the development of domestic hot water (DHW) preparation systems for residential buildings, in order to evaluate and optimize the final energy and the DHW comfort. The case study of this work is a big multi-family building composed of 96 flats. District heating (DH) is used to heat up the water in the storage tank located in the technical room. A distribution system connects the storage to all the fresh water stations (FWS) located in each flat.
The chosen approach is to simulate the building-level DHW preparation with a single heat exchanger (HX) which approximates the behaviour of all the HXs of the building. For this purpose, the simultaneity factor (fs) should be considered.
First, a representative model of the FWS for each flat is implemented in Matlab/Simulink and tested with two different control strategies of the circulation pump and two different DHW profiles, derived either from standard EN16147 or created as a stochastic profile.
From the flat-level model, a building-level model is derived. Four different building-level DHW profiles are used to evaluate the simultaneity factor, and so the peak load of the building, in order to size the HX for the whole building.
The DHW profiles (and so the simultaneity factor) and the parametrization of the HX influence the results. Final energy and DHW comfort (i.e. the DHW temperature and the “waiting time” to reach this temperature) are compared in each case.
The return temperature of the fluid sent back to the storage is also analysed. The development of the return temperature to the storage is influenced by the DHW profiles and the thermal capacity of the pipe.
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Hallqvist, Karl. "Högtempererat borrhålslager för fjärrvärme." Thesis, Uppsala universitet, Naturresurser och hållbar utveckling, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-231586.
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The district heating load is seasonally dependent, with a low load during periods of high ambient temperature. Thermal energy storage (TES) has the potential to shift heating loads from winter to summer, thus reducing cost and environmental impact of District Heat production. In this study, a concept of high temperature borehole thermal energy storage (HT-BTES) together with a pellet heating plant for temperature boost, is presented and evaluated by its technical limitations, its ability to supply heat, its function within the district heating system, as well as its environmental impact and economic viability in Gothenburg, Sweden, a city with access to high quantities of waste heat. The concept has proven potentially environmentally friendly and potentially profitable if its design is balanced to achieve a good enough supply temperature from the HT-BTES. The size of the heat storage, the distance between boreholes and low borehole thermal resistance are key parameters to achieve high temperature. Profitability increases if a location with lower temperature demand, as well as risk of future shortage of supply, can be met. Feasibility also increases if existing pellet heating plant and district heating connection can be used and if lower rate of return on investment can be accepted. Access to HT-BTES in the district heating network enables greater flexibility and availability of production of District Heating, thereby facilitating readjustments to different strategies and policies. However, concerns for the durability of feasible borehole heat exchangers (BHE) exist in high temperature application.Värmebehovet är starkt säsongsberoende, med låg last under perioder av högre omgivningstemperatur och hög last under perioder av lägre omgivningstemperaturer. I Göteborg finns en stor mängd spillvärme tillgängligt för fjärrvärmeproduktion sommartid när behovet av värme är lågt. Tillgång till säsongsvärmelager möjliggör att fjärrvärmeproduktion flyttas från vinterhalvår till sommarhalvår, vilket kan ge såväl lönsamhet som miljönytta. Borrhålsvärmelager är ett förhållandevis billigt sätt att lagra värme, och innebär att berggrunden värms upp under sommaren genom att varmt vatten flödar i borrhål, för att under vinterhalvåret användas genom att låta kallt vatten flöda i borrhålen och värmas upp. I traditionella borrhålsvärmelager används ofta värmepump för att höja värmelagrets urladdade temperatur, men på grund av höga temperaturkrav för fjärrvärme kan kostnaden för värmepump bli hög. I denna rapport föreslås ett system för att klara av att nå höga temperaturer till en lägre kostnad. Systemet består av ett borrhålsvärmelager anpassat för högre temperaturer (HT-BTES) samt pelletspannor för att spetsa lagrets utgående fluid för att nå hög temperatur. Syftet med rapporten är att undersöka potentialen för detta HT-BTES-system med avseende på dess tekniska begränsningar, förmåga till fjärrvärmeleverans, konsekvenser för fjärrvärmesystemet, samt lönsamhet och miljöpåverkan. För att garantera att inlagringen av värme inte är så stor att priset för inlagrad värme ökar väsentligt, utgår inlagringen från hur mycket värme som kyls bort i fjärrvärmenätet sommartid. I verkligheten finns betydligt mer värme tillgänglig till låg kostnad. När HT-BTES-systemet producerar fjärrvärme, ersätts fjärrvärmeproduktion från andra produktionsenheter, förutsatt att HT-BTES-systemets rörliga kostnader är lägre. I Göteborg ersätts främst naturgas från kraftvärme, men också en del flis. Kostnadsbesparingen beror på differensen för total fjärrvärmeproduktionskostnad med och utan HT-BTES-systemet. Undersökningen visar att besparingen är större om HT-BTES-systemet placeras i ett område där det är möjligt att mata ut fjärrvärme med lägre temperatur. Om urladdning från HT-BTES kan ske med hög temperatur ökar också besparingen. Detta sker om lagrets volym ökar, om avståndet mellan borrhål minskar eller om värmeöverföringen mellan det flödande vattnet i borrhålen och berggrunden ökar. Dessa egenskaper för lagret leder också till minskade koldioxidutsläpp. Storleken på besparingen beror dock i hög grad på hur bränslepriser utvecklas i framtiden. Strategiska fördelar med HT-BTES-systemet inkluderar; minskad miljöpåverkan, robust system med lång teknisk livslängd (för delar av HT-BTES-systemet), samt att inlagring av värme kan ske från många olika produktionsenheter. Dessutom kan positiva bieffekter identifieras. Undersökningen visar att HT-BTES-systemet har god potential att ge lönsamhet och minskad miljöpåverkan, och att anläggning och drift av lagret kan ske utan omfattande lokal miljöpåverkan. Det har också visats att de geologiska förutsättningarna för HT-BTES är goda på många platser i Göteborg, även om lokala förhållanden kan skilja sig åt. För att nå lönsamhet för HT-BTES-systemet krävs en avvägning på utformning av lagret för att nå hög urladdad temperatur utan att investeringskostnaden blir för stor. Undersökningen visar att om anslutning av HT-BTES-systemet kan ske mot befintlig anslutningspunkt eller till befintlig värmepanna kan investeringskostnaden minska och därmed lönsamheten öka. Placering av HT-BTES-systemet i områden med risk för överföringsbegränsningar kan också minska behovet av att förstärka fjärrvärmenätet, och således bidra till att minska de kostnader som förstärkning av nätet innebär. Betydelsefulla parametrar för att nå lönsamhet för HT-BTES-system inkluderar dessutom kostnaden för inlagrad värme liksom vilket vinstkrav som kan accepteras. Tillgång till HT-BTES möjliggör ökad nyttjandegrad och flexibilitet för fjärrvärmeproduktionsenheter, och därmed ökad anpassningsmöjlighet till förändrade förutsättningar på värmemarknaden. Dock återstår att visa att komponenter som klarar de höga temperaturkraven kan tillverkas till acceptabel kostnad.
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Duquette, Jean. "The potential benefits of combined heat and power based district energy grids." Thesis, 2017. http://hdl.handle.net/1828/7818.
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In this dissertation, an assessment is conducted of the potential benefits of combined heat and power (CHP) based district energy (DE) grids in energy systems of different scale having significant fossil fuel fired electrical generation capacity. Three studies are included in the research.
In the first study, the potential benefits of expanding CHP-based DE grids in a large scale energy system are investigated. The impacts of expanding wind power systems are also investigated and a comparison between these technologies is made with respect to fossil fuel utilization and CO2 emissions. A model is constructed and five scenarios are evaluated with the EnergyPLAN software taking the province of Ontario, Canada as the case study. Results show that reductions in fuel utilization and CO2 emissions of up to 8.5% and 32%, respectively, are possible when switching to an energy system comprising widespread CHP-based DE grids.
In the second study, a high temporal resolution numerical model (i.e. the SS-VTD model) is developed that is capable of rapidly calculating distribution losses in small scale variable flow DE grids with low error and computational intensity. The SS-VTD model is validated by comparing simulated temperature data with measured temperature data from an existing network. The Saanich DE grid, located near Victoria, Canada, is used as the case study for validation.
In the third study, the potential benefits of integrating high penetrations of renewable energy via a power-to-heat plant in a small scale CHP-based DE grid are investigated. The impacts of switching to a CHP-based DE grid equipped with an electric boiler plant versus a conventional wave power system are compared with respect to fossil fuel utilization and CO2 emissions. The SS-VTD model is used to conduct the study. The energy system of the Hot Springs Cove community, located on the west coast of Vancouver Island, Canada is used as the case study in the analysis. Results show that relative to the conventional wave power system, reductions in fuel utilization and CO2 emissions of up to 47% are possible when switching to a CHP-based DE grid.Graduate
Books on the topic "District heating pipes"
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Phetteplace, Gary E. Optimal design of piping systems for district heating. [Hanover, N.H.]: U.S. Army Corps of Engineers, Cold Regions Research & Engineering Laboratory, 1995.
Find full textBook chapters on the topic "District heating pipes"
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Nilsson, S. F. "New developments in pipes and related network components for district heating." In Advanced District Heating and Cooling (DHC) Systems, 191–214. Elsevier, 2016. http://dx.doi.org/10.1016/b978-1-78242-374-4.00009-4.
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Wagner, B., and T. Neidhart. "A new backfill material enhancing axial bedding of district heating pipes." In Energy Geotechnics, 105–12. CRC Press, 2016. http://dx.doi.org/10.1201/b21938-19.
Full textConference papers on the topic "District heating pipes"
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Adl-Zarrabi, Bijan. "Super insulation material in district heating pipes." In 7th International Building Physics Conference. Syracuse, New York: International Association of Building Physics (IABP), 2018. http://dx.doi.org/10.14305/ibpc.2018.be-3.05.
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Huber, Michael, and Dharma Wijewickreme. "Response of Buried District Heating Pipelines Under Relative Axial Movements." In 2014 10th International Pipeline Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/ipc2014-33530.
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District heating (DH) systems are commonly used in urban areas to distribute thermal energy from central heat sources. Buried pipes, with a composite cross-sectional construction, are used transport a heated medium, usually water. These pipes expand and contract radially and axially due to changing water temperatures, invoking soil-pipe interaction situations during operation, and potentially leading to significant pipeline material strains. A series of full-scale tests were undertaken to specifically investigate the influence of thermal expansion on axial pullout resistance using DH pipes buried in sand in a full-scale soil-pipe interaction test chamber. During testing, the pipe is filled with water that is subjected to temperature changes to simulate field conditions. Axial pipe pull-out tests were conducted after applying a given “heating history” with axial pullout force and displacements recorded. The work leads to better understanding of soil-pipe interaction mechanisms generating currently scarce data needed for robust and cost-effective designs of DH pipe systems.
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Lefter, R., and D. Popescu. "Analysis of “Conti” pre-insulated pipes with diffusion barrier versus traditional pre-insulated pipes used in district heating networks." In 2012 International Conference and Exposition on Electrical and Power Engineering (EPE). IEEE, 2012. http://dx.doi.org/10.1109/icepe.2012.6463806.
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Ulloa, Priscilla, and Nickolas J. Themelis. "Doubling the Energy Advantage of Waste-to-Energy: District Heating in the Northeast U.S." In 15th Annual North American Waste-to-Energy Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/nawtec15-3201.
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In District Heating (DH), a large number of buildings are heated from a central source by conveying steam or hot water through a network of insulated pipes. Waste-to-Energy (WTE) signifies the controlled combustion of municipal solid wastes to generate electrical and thermal energy in a power plant. Both technologies have been developed simultaneously and are used widely in Europe. In the United States, however, WTE is used principally for the generation of electricity. The advantages of district heating using WTE plants are: overall fuel conservation, by increasing the thermal efficiency of WTE, and overall reduction of carbon dioxide emissions to the atmosphere. The purpose of this study was to examine the current situation of district heating in the U.S. and determine the potential for applying DH to existing WTE plants. A preliminary evaluation was conducted of DH application at two WTE facilities in Connecticut: the Wheelabrator Bridgeport and the Covanta Preston facilities. Using a Canadian methodology, the minimal distribution heating network costs for Bridgeport were estimated at about $24 million dollars for providing heat to a surrounding area of one square mile and the DH revenues at $6.8 million.
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Zinko, Heimo, and Bengt Perers. "TX model: a quantitative heat-loss analysis of district heating pipes by means of IR surface-temperature measurements." In SPIE's 1995 Symposium on OE/Aerospace Sensing and Dual Use Photonics, edited by Sharon A. Semanovich. SPIE, 1995. http://dx.doi.org/10.1117/12.204851.
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Dell, Robert, C. S. Wei, Raj Parikh, Runar Unnthorsson, Nicholas Mitchell, and William Foley. "Design and Construction of a Heated Garden System Utilizing Steam Condensate From an On Site Boiler." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-68180.
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Municipal District Heating Services and Combined Heat and Power (CHP) systems can produce waste heat in the form of steam condensate and hot water. The authors have demonstrated (IMECE2014-39066) the potential of open field heating of green roofs to reduce thermal pollution, save potable water, and while increasing plant growth. Subsequent research in both Iceland and New York City using similar systems has resulted in the growth of out of region plants. The latest plant growth results are detailed. The latest research has indicated additional potential impediments, including the need for an additional CHP system pump. A thorough structural analysis on existing older roofs is necessary to avoid an overstressed roof. Substantial UV shielding of the plastic piping and upgrading of the pipes from braided PVC to PEX(a) was also needed. The details of selecting an appropriate heat exchanger were analyzed for a specific building and associated construction details are provided.
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Al Edhari, A. J., and C. C. Ngo. "Experimental Study of Thermal Energy Storage Using Natural Porous Media." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71714.
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Thermal energy storage has been an area of research interest due to the need to store solar energy or excess energy for later use in many applications including district heating. The focus of a lot of research is on exotic and expensive storage media. This paper presents an experimental study of thermal energy storage using porous media readily available and commonly found in nature such as sand, soil, pebble rocks and gravel. This study also considers a simple and inexpensive thermal storage system which could be constructed easily and examines what could be done to increase the thermal storage performance. The thermal storage system examined in the present study was a thermal energy storage unit with embedded horizontal pipes carrying water as the heat transfer fluid for thermal charging. Different thermal storage configurations were examined by adjusting the thermal charging temperature and using different storage media. The temperature distribution within the storage media was monitored for 10 hours using a data acquisition system with K-type thermocouples. The results indicate that a thermal storage system using sand as storage media is slightly better compared with gravel or pebble rocks as storage media.
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Verda, Vittorio, and Serena Fausone. "Exergoeconomic Analysis of District Heating Systems." In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90351.
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District heating is a rational way to use fossil fuels for domestic heating (and cooling) in towns, especially if it is joined to a cogenerative production of electricity. The aim of this paper is to propose the use of exergoeconomic procedures for the design and analysis of district heating systems. Network design basically involves the selection of the areas to be connected to the network as well as the selection of some design variables as the pipe diameters, the location of pumps etc. This choice is operated assuming primary energy consumption as the objective function to be minimized. The application of these concepts is operated through a probabilistic approach derived from Simulated Annealing. An application to the Turin district heating system is presented here. The system is composed of a cogenerative combined cycle, some auxiliary boilers and the pipe network. An exergetic cost is associated to each user or potential user. This information is used to evaluate the opportunities for future expansions of the served area as well as the variation in some of the operating parameters.
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Zeng, Jing, Qun Xu, Youzhi Ning, and Xiuling Zhang. "Pipe Network Optimization in District Cooling/Heating System: A Review." In 2019 International Conference on Robots & Intelligent System (ICRIS). IEEE, 2019. http://dx.doi.org/10.1109/icris.2019.00042.
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Jonsson, Magnus Thor, and Lilja Magnusdottir. "Coupled Pump and Pipe System Analysis for Optimum Design of District Heating System." In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-65996.
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This paper describes a novel approach for optimizing a district heating distribution network under various flow rate conditions. For district heating systems, the demand or the flow and pressure at each node varies over the time of year. The flow control that affects the operational cost can be based on the variable speed and the on/off control on serial pumping or pressure controlled valves. In the pipe system design, the topology, or the pipe layout, and the pipe diameter is optimized using genetic algorithms. Standardized methods are used for calculating the pipe thickness, supports, anchors and the thermal expansion loops. The interconnection between the pipe system and the pump station design is discussed. The objective is to minimize the total or life cycle cost (capital maintenance and operational cost), subject to ensuring demands or constraints at all points. The results are compared to classical methods where the pump station and the pipe system are designed separately and the improvements are discussed. The problem is formulated by developing an objective function where the optimization parameters define the pump arrangement, pipe system topology, and pipe diameters. The pump station and pipe system optimization consist of selecting components from a pre-defined set of elements and is implemented with discrete decision variables. Optimization of pipe elements consists of optimizing the diameter, after the topology has been defined, and is implemented with discrete variables. Flow distribution and pressure analysis is performed. Thicknesses, pressure classes, supports, expansion loops and anchors are not part of the optimization parameters, but are determined during the evaluation of the objective function. Each time the objective function is evaluated, the pipe system is designed in a sub-optimization according to given loads. The pressure head constraints are used to design the pumping curves. The method is tested on a district heating system in Reykjavik, Iceland.