太阳能-土壤耦合热泵长年蓄热土壤热平衡分析

ANALYSIS ON SOIL HEAT BALANCE IN A SOLAR-GROUND COUPLED HEAT PUMP SYSTEM WITH SEASONAL STORAGE ALL THE YEAR ROUND

以严寒地区季节性蓄热太阳能-土壤耦合热泵系统为研究对象,通过数值模拟的方法,对该系统在长年蓄、取热情况下土壤的热平衡状况进行分析并对系统模型进行实验验证。研究结果表明:系统在相同控制条件下运行,蓄热量大于取热量,土壤温度得到有效提升,但由于连续多年蓄热土壤中出现热堆积现象,蓄热量逐年下降并趋于平稳;土壤温度的逐年升高使热泵COP保持在较高水平,但每年提升的幅度不大,可在土壤平均温度趋于稳定时减少蓄热量,使土壤热量达到平衡。

The solar-ground coupled heat pump system with seasonal heat storage in severe cold area was taken as the research object. The numerical simulation method was used to analyze the soil heat balance situation in the case of annual heat storage and extraction. The numerical models of system were verified by experiment. The simulation results showed that when the system ran under the same controlled conditions and the heat storage capacity was made over the heat extraction capacity, the soil temperature was raised effectively, but because of the annually heat storage, the hot stack appeared in the soil, which made the heat storage capacity descend year by year and tend to be stable ; the heat pump＇ s COP was maintained at a higher level because of the increasing of the soil temperature year by year, but the annual increased range was small, so the heat storage capacity could be decreased when the average soil temperature tends to be stable to make the heat in the soil balanced.