Change search
ReferencesLink to record
Permanent link

Direct link
Reduction of prime energy consumption by ground source heat pumps in a warmer world
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Architecture and Water.
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Much of the energy used worldwide is supplied by fossil fuels (~85 %) while renewable energy sources supply approximately 6 %. A sustainable future urgently requires worldwide efforts to reduce primary energy consumption and increase use of renewable energy sources. Heating and cooling in the industrial, commercial, and domestic sectors accounts for more than one third of the world’s total energy consumption. Consequently, the implementation of more efficient heating/cooling systems has clear potential to save both energy and the environment. However, the use of renewable energy systems for heating and cooling applications has received relatively little attention compared with other applications such as renewable electricity or biofuels for transportation. Up until now, renewable energy sources supply only around 2-3% of the annual global heating and cooling demand (excluding traditional bioenergy).Heat pump systems are becoming more common for heating and cooling purposes. Such systems extract energy from a relatively cold source to be injected into the conditioned space in winter or alternatively, extract energy from conditioned spaces to be injected into a relatively warm sink in summer. The driving energy of the heat pump strongly depends on the temperature difference between the conditioned space and the heat source/sink. More specifically, extracting heat from warmer source during the winter and injecting heat into colder sink during the summer leads to a better coefficient of performance (COP) and, consequently, less energy use.Since the ground under certain depth is warmer than the air during winter and colder during summer, using the ground as the heat source/sink of the heat pump results in better COP. Due to their high thermal performance compared to conventional heating and cooling systems, ground source heat pump (GSHP) systems are increasingly being used to reduce energy consumption. Essentially GSHP systems refer to a combination of a heat pump and a system for exchanging heat from the ground. The GSHPs move heat from the ground to heat buildings and houses in the winter or alternatively, move heat from the buildings and houses to the ground to cool them in the summer. It is worth mentioning that the operating temperature of a borehole field depends on the annual mean air temperature and the ratio of heating to the cooling demand of the buildings. Hence, the ongoing global warming and improvement of the thermal quality of the building envelope have a direct impact on the performance of GSHPs.No GSHP system has yet been built in Syria despite the fact that the local conditions in many ways are more favorable than in for example Sweden, which has the world’s third biggest installed facility.In addition to emphasizing the importance of using ground source heat pumps in reaching the renewable energy goals of mitigating the climate change, the current work:• Reported the first thermal response test (TRT) that was performed in Syria that is required in order to determine the ground thermal properties, which are needed for the proper design of borehole heat;• Provided a simple method that gives the change in ground temperature as a function of the surface warming;• Showed the impact of GW in combination with the building envelope quality on the thermal performance of GSHP and, consequently, on the driving energy of GSHPs;• Introduced a method that can be implemented to improve the thermal characteristics of ground heat exchanger.In order to calculate the effective thermal conductivity of the ground and the thermal resistance of the ground heat exchanger, a computer model was built, which can be used to analyze the experiment data. Furthermore, a new method that can be used to calculate the thermal load of buildings was developed and a computer model was built too.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2011.
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
Research subject
Water Resources Engineering
Identifiers
URN: urn:nbn:se:ltu:diva-18209Local ID: 76b63a03-267c-481e-8611-174f674a3177ISBN: 978-91-7439-334-7OAI: oai:DiVA.org:ltu-18209DiVA: diva2:991216
Note
Godkänd; 2011; 20110928 (khamoh); DISPUTATION Ämnesområde: Vattenteknik/Water Resources Engineering Opponent: Professor Jeff Spitler, School of Mechanical and Aerospace Engineering, Oklahoma State University, U.S.A. Ordförande: Professor Bo Nordell, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Fredag den 2 december 2011, kl 10.00 Plats: F1031, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29Bibliographically approved

Open Access in DiVA

fulltext(9545 kB)5 downloads
File information
File name FULLTEXT01.pdfFile size 9545 kBChecksum SHA-512
83fdd1074c8d705920b415e850379d29e1d83fa223c9190b74651bae8a40e8a7e0be8ac3eec9ffa15701df4e0a3eefcf07bf1066059875df8bf275b610d4cc8d
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Kharseh, Mohamad
By organisation
Architecture and Water

Search outside of DiVA

GoogleGoogle Scholar
Total: 5 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 10 hits
ReferencesLink to record
Permanent link

Direct link