竖直地埋管换热器钻孔外换热解析模型研究现状
Review of analytical models for heat transfer outside borehole of vertical ground heat exchangers
摘要：
根据对热源形状假定的不同，将竖直地埋管换热器钻孔外换热解析模型分为线热源、面热源、体热源3大类，对这3类模型进行了比较分析。结果表明，实际工程中3类模型设计结果几乎没有差别；有限长和无限长热源模型需要很长的时间计算结果才会有明显差异，在满足冷热负荷平衡条件下可以不考虑换热器长度的影响；在不考虑渗流影响情况下，当冷热负荷大致平衡时应采用计算较为方便的无限长线热源模型；在有渗流情况下，当渗流速度达到10-6 m/s时应考虑其影响。
Abstract：
Based on the assumed shapes of heat source, divides the analytical models for heat transfer outside borehole into three types such as line heat source model, surface heat source model and solid heat source model. Compares and analyses the three types of models. The results show that for practical design they are almost the same. The comparison between the infinite and finite heat source models indicates that obvious difference between the two types of models can be observed only after a long time of heat transfer process , and the influence of the heat exchanger’s length can be neglected with a balance of thermal load. Without the seepage in the ground, if the thermal load is kept balanced, the infinite line heat source model should be applied in practical design because it is simple. If the seepage velocity reaches 10-6 m/s, its effect should be considered.
Keywords:verticalgroundheatexchanger,heattransferoutsideborehole,analyticalmodel,lineheatsource,surfaceheatsource,solidheatsource,lengthofheatexchanger,seepagevelocity