Performance analysis of shallow depth hydrothermal enhanced geothermal system for building heating

The energy reserves of hot dry rock (HDR) and hydrothermal system are abundant in China. However, there is low-level development and utilization due to high risk, huge capital investment and immature technology for HDR and dispersion distribution characteristic for hydrothermal system. Here a shallow depth enhanced geothermal system (SDEGS) is proposed, which is formed by fracturing low yield hydrothermal system to increase permeability and volume flow rate. It is indicated that, due to the promoted volume flow rate of 500 m(3)/h, the extracted thermal output from SDEGS with reservoir volume of 5 x 10(7) m(3) is 43940.92 kW. Generally, it can provide heating for a 1255454.86 m(2) building. By changing the volume flow rate and injection water temperature, it is easy to adjust the extracted thermal output to meet the thermal load requirement under different outdoor ambient temperature. The application of SDEGS technology will promote the rapid development of geothermal energy and solve the smog problem easily and effectively.