Feasibility analysis of Earth-Air Heat Exchanger (EAHE) in a sports and culture center in Tianjin, China

This thesis calculated and analyzed the feasibility of EAHE in a building in Tianjin, China through theoretical calculation and numerical simulation. According to the theoretical model, the thermal performance of EAHE were obtained by calculating the soil temperature, the calculated temperature of the soil in intermittent operation, the heat release coefficient of tunnel wall and the heat transfer coefficient during intermittent operation. CFD software was used to model summer operating conditions, the hourly air temperature in July in Tianjin was taken as the air temperature of tunnel inlet, simulated the intermittent operation of EAHE for one week, recorded the average temperature of the soil on the tunnel walls and outlet temperature of the working hours of EAHE, data fitting was carried out for the cooling amplitude in the working period, the numerical simulation results accord with the theoretical calculation values. The results of the study indicate that the higher the inlet air temperature, the greater the temperature drop; the soil around the tunnel walls has the characteristic of reducing temperature; considering the modification of the fan temperature rise, COP in winter is greater than that in summer. The energy-saving effect is more significant in winter.