| Title | Study on the Recovery Characteristics of Shallow Geothermal Energy |
|---|---|
| Authors | YU Yuan, LI Ningbo, YANG Junwei, LI Xiang, CAO Lei, YU Hao, XIAO Tianpeng |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Shallow geothermal energy, Buried pipe, Ground source heat pump (GSHP), Ground temperature field, Temperature monitor, Recovery rate of ground temperature |
| Abstract | In recent years, with the country's emphasis on resources and environment, as a clean and renewable energy source to energy conservation and emission reduction, the contribution of shallow geothermal energy has increased year by year. GSHP technology is a main way to develop and utilize shallow geothermal energy. The heat transfer between GSHP system and soil is mainly based on the heat conduction of the rock and soil during the system operation. It will change the geothermal field of the heat exchange zone to some extent in the process of operation, while the change of the geothermal field directly affects the geological environment of the heat exchange zone. This paper takes a GSHP system in Beijing as an example to carry out the monitoring and data analysis research on the geothermal field, and studies the distribution of the original geothermal field and the recovery performance of the heat pump system during operation, especially in the transitional season. It can be concluded through analysis that the change of temperature field is closely related to the operation of the system, and it changes regularly. The variation range and variation trend of temperature curve at different depths are almost the same, showing that the temperature is lower in winter, while the temperature is rising slowly in transition season and gentle in summer. According to the distribution of time and space, it analyzes the recovery situation of heat exchange holes in different periods and different regions. The recovery rate of ground temperature is introduced to illustrate the recovery extent of ground temperature in different strata, and it makes a comprehensive analysis on characteristics of geothermal field from the formation lithology and groundwater dynamic changes. Through the monitoring of the geothermal field, we can master the dynamic characteristics of the geothermal field in the heat exchange zone, and scientifically guide the system operation, so as to provide reference for the application of GSHP system, which is of great significance to achieve the optimal performance of the system and protect the geological environment. |