22 May 2002
A middle-sized Geo-Heat Gradient Utilization System with heat pumps for Space heating was built up in the Campus of Beijing Polytechnic University since 2000. Geothermal hot water was from the production well with 1600 m deep & temperature of 52 ºC. Heat has been supplied from the aquifer hot water to the space heating system with heat pumps for 2000 m2. building area. A Plate Heat Exchanger has been used between the Geo-thermal hot water and the cycled hot water. Cycled water will be supplied to heating system. Heat Pumps which can stand 30-35ºC of Entering Source Water Temperature (ESWT) were installed in system. Fan-coil units with low entering water temperature were installed underneath the windows for low temperature heating. Sensors for measuring the temperature, water flow rate, pressure, power etc have been fixed in the system for technical and economical analysis. Geothermal hot water could be utilized fully until 10–20 ºC then returning to re-injection well. Cooling was supplied in summer by reversed cycle of heat pump. Total Efficiency?and Utilization Factor of Geo-fluid ? will be used for rating this system . A special test told us the data will be ?around 5-7,?around 0.8.