地埋管管群换热器温度场影响因素的模拟研究

Ground-Coupled GroupHeat Exchanger Factors Affecting Temperature Simulation

目的研究不同影响因素下地埋管管群换热后土壤温度场的变化,为实际工程地埋管设计提供理论依据.方法通过Gambit建立地埋管管群模型,在Fluent中设置不同的参数,模拟地源热泵运行一年土壤温度变化情况.结果回填材料的导热系数分别为1.6 W/(m·K)、2.0 W/(m·K)、2.4 W/(m·K)时,一年后土壤温度的加权平值分别为15.114℃、15.137℃、15.134℃;顺排和叉排排列方式下,一年后土壤温度加权平均值分别为15.13℃和15.12℃;渗流速度分别为1.0×10-6m/s、2.0×10-6m/s、3.0×10-6m/s时,一年后土壤温度的加权平均值分别为15.900℃、15.988℃、15.993℃;孔隙率分别为0.232、0.332、0.432时,一年后土壤温度的加权平均值分别为15.017℃、15.027℃、15.08℃.结论回填材料的导热系数不宜大于土壤的导热系数,叉排方式下的换热效果优于顺排,地下水渗流速度越大,越利于土壤温度的恢复,孔隙率较大时,土壤温度变化波动较小.

To study the change of soil temperature field after heat transfer from ground-coupled group under different influencing factors,which provides theoretical basis for practical engineering design of buried pipe. The model of ground-coupled group was established by Gambit and different parameters were set up in Fluent to simulate the variation of ground temperature in ground source heat pump（GSHP） for one year. When the respectively thermal conductivity of backfill materials are 1. 6 W/（m·K）,2. 0 W/（m·K）,2. 4 W/（m·K）,the weighted average values of soil temperature after one year are as follows： 15. 114 ℃,15. 137 ℃,15. 134 ℃; Under the cross management and the series management,the weighted average values of soil temperature after one year are asfollows： 15. 13 ℃ and 15. 12 ℃; When seepage velocity are 1. 0 × 10-6 m/s、2. 0 × 10-6 m/s、3. 0 × 10-6 m/s,respectively,the weighted average value of soil temperature after one year are as follows： 15. 900 ℃,15. 988 ℃,15. 993 ℃; When the soil porosity are 0. 232,0. 332 and 0. 432,respectively,the weighted average values of soil temperature after one year are as follows：15. 017 ℃,15. 027 ℃ and 15. 08 ℃. The thermal conductivity of backfill material should not be greater than that of soil,and the heat transfer efficiency of cross arrangement is better than that of series arrangement. The larger seepage velocity of groundwater is,the more favorable of soil temperature recovers. When the soil porosity is larger,the fluctuation of soil temperature becomes smaller.