Impact of soil model complexity on the long-term thermal performance prediction of a new shallow bore ground heat exchanger. (19th July 2022)

• Record Type: Journal Article
• Authors: Shi, Liang; Qu, Ming; Liu, Xiaobing; Zhang, Mingkan; Wang, Lingshi
• Is Part Of: Science and technology for the built environment. Volume 28:Number 6(2022)
• Page Start: 717
• Page End: 728
• Publication Date: 2022-07-19
• Subjects: Heating -- Periodicals; Ventilation -- Periodicals; Air conditioning -- Periodicals; Refrigeration and refrigerating machinery -- Periodicals; Indoor air quality -- Periodicals; Indoor air quality; Air conditioning; Heating; Refrigeration and refrigerating machinery; Ventilation; Periodicals; 697
• DOI: 10.1080/23744731.2021.1908038
• Languages: English
• ISSNs: 2374-474X

Abstract

Abstract : Shallow bore ground heat exchangers have been investigated in recent years because they have the potential to reduce the initial cost of the ground source heat pump system. Correctly modeling the transient heat transfer between the ground heat exchanger and the surrounding soil is essential for predicting a ground heat exchanger's performance. Simplification of the soil model could increase computation speed but sacrifice accuracy. This study investigates the impact of the soil model complexity on the annual performance prediction of a new shallow bore ground heat exchanger, the underground thermal battery (UTB). A simple 1D soil model and a more detailed 2D soil model were implemented, and they were validated against a 3D soil model. The resulting predictions of the UTB's response from the 1D and 2D models to a given thermal load in different climates were compared. The results show that the root mean square differences between the hourly temperatures of the UTB during a year predicted using the two soil models range from 1.17 °C to 3.39 °C. As a result, the difference in the annual power consumption of the heat pump was between 0.7% and 3.4%. Furthermore, the dimensions of the UTB affected its performance, and a longer UTB was less sensitive to the soil models.