土壤源热泵竖直U型埋管换热器冬季性能测试

Performance Test of Vertical Buried U-tube Heat Exchanger for Ground-source Heat Pump in Winter

对土壤源热泵竖直 U 型埋管换热器进行了冬季性能测试。循环水质量流量分别取4.0、3.5、3.0 t/h 各运行5 d,测量与埋管井不同距离的3口测温井的土壤温度。在以埋管井为圆心的作用半径中,距埋管井较近的测温井土壤温度受到埋管井温度变化的影响较大;反之,受埋管井温度变化的影响较小。随着室外温度下降,虽然埋管换热器循环水质量流量减小,但土壤温度还是有所下降。热泵机组平均制热性能系数、单位井深热流量随着埋管换热器循环水质量流量的下降有所下降。

The performance test of vertical buried U-tube heat exchanger for ground-source heat pump is conducted in winter. The mass flow rates of circulating water are selected respectively as 4.0, 3.5 and 3.0 t/h during five-day operation. The soil temperatures in three temperature measurement wells with different distances from buried tube wells are measured. At the action radius where the buried tube well is the circle center, the soil temperature in the temperature measurement well closer to the buried tube well is more influenced by the temperature change of the buried tube well; on the contrary, it is less influenced by the temperature change of the buried tube well. When the outdoor temperature is reduced, though the mass flow rate of circulating water of buried tube heat exchanger is decreased, the soil temperature is still reduced. The average heating performance coefficient of heat pump unit and the heat flow rate per unit well depth are reduced with the decrease of the mass flow rate of circulating water of buried tube heat exchanger.