| Author: | Zhao, Dongyao |
| Title: | Improving the energy efficiency of ground source heat pump system in winter by auxiliary heat source |
| Advisors: | Yang, H. X. (BSE) |
| Degree: | M.Eng. |
| Year: | 2017 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Ground source heat pump systems |
| Department: | Department of Building Services Engineering |
| Pages: | viii, 73 pages : color illustrations |
| Language: | English |
| Abstract: | Ground Coupled Heat Pump systems use the ground or the ground water flow as a heat source-sink to provide space heating and cooling and are generally more energy efficient than heat pumps that use outdoor air as a heat source-sink. However, experimental studies on the GCHP system are still insufficient. Although Ground Coupled Heat Pump systems are regarded as one of the effective energy saving technologies, and obtain popular application for air conditioning in summer and space heating in winter all over the world, the energy efficiency of GCHP system is still not good enough. To improve the energy efficiency of GCHP systems, this paper gives the detailed solutions of the heat balance problem using auxiliary cold and heat source to assist the running of ground source heat pump systems, such as waste heat, natural gas, solar energy and so on. All of them can be used to compensate the heat extraction from the earth by the GCHP systems. The paper can also provide some adjustment methods of GCHP systems to guarantee higher efficient conduct of GCHP systems. A general introduction on the GCHP systems and its development were briefly presented first. This paper mainly studied the selection of the best auxiliary heat source for the traditional ground source heat pump to improve the operating efficiency of the heat pump. Second, two auxiliary heat sources were selected: gas boiler and solar collector. Then a typical residential building in Jinan was chosen for a detailed gas boiler auxiliary ground source heat pump system case study. Both experiments and simulation were employed to examine the efficiency of proposed GCHP system. By means of comparisons of the temperature, COP, geothermal imbalance rate and economy of conventional ground source heat pump and gas boiler auxiliary ground source heat pump system, the results demonstrated the operational advantages of the composite system. Next, this paper chose a solar energy heat pump system laboratory in Jinan as the research platform of solar ground source heat pump system. Using the laboratory monitoring platform to record the system temperature field data and the value of COP and using the geothermal star software to simulate the annual temperature field curve, It is found that after using solar composite system, both of the inlet water and outlet water temperature in winter were more than 6°C. The average temperature of water was 10°C and the average COP value was 3.65 in winter. Finally, after doing a systematic economic analysis, the advantages of the solar heat pump system were demonstrated. Overall, after adding the gas-fired boiler and the solar collector into ground source heat pump system, the operating efficiency of the system has been greatly improved. |
| Rights: | All rights reserved |
| Access: | restricted access |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| 991021959947803411.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 1.35 MB | Adobe PDF | View/Open |
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