为实现土壤源热泵系统的合理设计和科学应用,避免系统常年运行后由于土壤吸放热量不一致导致土壤温度变化,通过对该系统所利用浅层土壤蓄热能资源量进行计算分析,明确了可利用土壤蓄热能资源量估算方法.利用地下埋管换热器热渗耦合数学模型,对土壤源热泵系统冬夏季土壤释吸热量相等即按照可利用土壤蓄热能资源量来设计系统,以及冬夏季土壤释吸热量不相等2种情况进行了理论模拟和分析.结果表明:当按照可利用资源量来设计系统时全年运行后土壤温度恢复至初温;而当夏季吸热量高于冬季释热量25%时,土壤平均温度升高了0.32℃,有利于下一年冬季运行但不利于下一年夏季运行.进行可利用浅层土壤蓄热能资源量分析,综合全年的冷热释取来设计土壤源热泵系统的容量,有利于保证土壤温度的回归和系统常年高效运行.在实际土壤源热泵系统应用设计时,对于夏季负荷占优地区,要综合考虑土壤经过冬季放热及过渡季散失之后夏季可供取出的冷量来估算资源量;反之亦然.
The soil temperature change year by year has a bad impact on the operation efficiency of ground source heat pump system (GSHP) which is caused by unreasonable design. Therefore it is necessary to make analysis for utilizable shallow thermal energy stored in the soil in order to realize the good design and application of GSHP system. With a coupled heat conduction and heat advection numerical model for ground heat exchanger, the theoretical calculations are done to make sure the impact of equal thermal energy injection into soil and extraction from soil which is in accordance with utilizable soil thermal energy method, and unequal case. The results show that the soil temperature almost goes back to the original state after one year for the case under utilizable soil thermal energy method. While for the other case with 25% more thermal energy gain in summer, the mean soil temperature is higher than the initial one by 0. 32℃ which is better for the opera- tion in winter time but not for summer time. Therefore, for the cooling load dominated area, the utilizable cool energy amount in summer should be estimated after considering the heat gain of soil in winter and heat loss in intermediate season. It is true for the converse too.