Study on the heating system combined subway exhaust heat with geothermal source heat pump

The reasons and regularities of heat yielded by subway were analyzed, and the exhaust heat in winter which could be reclaimed was calculated. According to the peculiarity of the exhaust heat yielded by subway, the tests were carried out by a set of experimental devices, and then the best combine way and operating control mode of system were chosen. The experimental results are obtained as following: Only operating air source heat pump could supply heat when subway exhaust heat could satisfy the heating load of building, the average COP of this system is 4.91; Operating geothermal-source heat pump could alone supply heat to building when subway could not provide any exhaust heat, the average COP of this system is 3.82; The average COP of the combine system of subway exhaust heat-geothermal source heat pump is 3.31 during supply heat.