某地源热泵示范工程土壤热平衡研究

Study on soil thermal balance of a ground source heat pump system

地源热泵作为清洁能源在中国发展迅速并主要用于大型公用建筑,若大规模开发利用使得土壤发生冷热堆积现象,会对系统效率产生影响。本文以山东省章丘市某地源热泵示范工程为例,利用两个供暖期、一个制冷期的监测数据,分析不同深度不同地层在工程运行过程中对土壤温度场产生的影响。研究结果显示,以砂岩、泥岩为主要岩性的地层,在地埋管间距为3.5m、冬季负荷大于夏季负荷的情况下,管群中心地带较外围冷负荷堆积情况严重,系统运行效率降低。建议冬季启用太阳能供暖系统并采用间歇运行的方式,解决取放热不平衡的问题。

As a renewable clean energy, the ground source heat pump （GSHP） system has been developed rapidly and mainly applied in the large communal buildings in China. If the large-scale development and utilization of the ground heat, cold and heat accumulation in the soil will be caused, and the system efficiency will be affected. One GSHP system located in Zhangqiu has been continuously monitored during two heating periods and one cooling period, and the influence of soil temperature under heating and cooling performance of the GSHP system is analyzed both considering different depth and different soils. The study results show that in case of the unevenly distributed load with heating load greater than cooling load and U-pipe intervals at 3.5m in sandstone or mudstones, cold accumulation in central of the underground is worse than the surrounding, and energy efficiency is reduced. Solar heating system is suggested with intermittent operation in winter in order to keep soil thermal balance.