Petroleum Reservoir Evaluation and Development ›› 2023, Vol. 13 ›› Issue (6): 726-740.doi: 10.13809/j.cnki.cn32-1825/te.2023.06.003

• Geothermal Energy Development and Utilization • Previous Articles     Next Articles

Overview of solutions to improve efficiency of ground source heat pump system

ZHANG Yuping1(),YANG Xiao2,LIU Jun1,LIU Boyang3,TANG Fujiao2(),TAN Yiqiu2   

  1. 1. Key Laboratory of Coal Resources Exploration and Comprehensive Utilization, Ministry of Natural Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an, Shaanxi 710026, China
    2. School of Transportation Science and Engineering, Haerbin Institute of Technology, Harbin, Heilongjiang 150006,China
    3. Shaanxi Zhongmei New Energy Co. Ltd., Xi’an, Shaanxi 710054, China
  • Received:2023-03-13 Online:2023-12-26 Published:2024-01-03

Abstract:

Shallow geothermal energy, with applications ranging from road snow melting and deicing to building heating/cooling, primarily utilizes closed-loop vertical buried pipes for resource exploitation. These pipes function by exchanging heat with the subterranean zone under specific cooling or heating loads. Given the limited capacity of a single vertical ground heat exchanger to harness geothermal resources, arrays of these exchangers are more commonly employed to effectively tap into shallow geothermal resources. However, the underground temperature field can be significantly affected by the heat exchange process between the ground heat exchanger array and the surrounding soil. Improper design and operational conditions can lead to an imbalance in the underground temperature field, potentially resulting in energy deficiencies and the malfunctioning of Ground Source Heat Pump Systems(GSHPS). Therefore, optimizing the design and operation scheme of ground heat exchanger array is the key to solve the imbalance of underground temperature field. The review summarizes the domestic and foreign research results, outlining various methods for energy storage and removal, incorporating auxiliary heating and cooling sources, and exploring relevant optimization techniques. The borehole array design optimization methods include primarily the distance between the pipe and the borehole layout. The energy storage/removal section mainly introduces the latest research results of borehole heat exchanger array by using external heat/cold sources such as solar energy and industrial waste heat. The auxiliary method mainly describes the latest researches on the application of resources like solar energy and heating towers. The operation control strategy mainly analyzes the operation control of the ground source heat pump system, including the peak cooling and heating load operation, intermittent operation, partition operation, system control strategy, etc. By thoroughly examining these optimization approaches and operational control strategies, the review provides a comprehensive analysis of the advantages and disadvantages of each scheme. This detailed evaluation serves as a valuable reference for improving the energy efficiency of GSHPS, ensuring sustainable and effective utilization of shallow geothermal resources.

Key words: geothermal energy, ground heat exchanger array, underground temperature field, energy storage, auxiliary heating/cooling source, control strategy

CLC Number: 

  • TE965