地源热泵地埋管换热器传热研究（3）：变热流边界条件下单U形地埋管换热器的非稳态传热特性
Heat transfer of ground heat exchanger for GSHP（3）：transient heat transfer characteristic of U-type ground heat exchanger with variable heat flow boundary
摘要：
采取数值计算与解析计算相结合的方法，研究变热流边界条件下单U形地埋管换热器的非稳态传热特性。以钻孔壁为边界，将计算区域分为两个部分，钻孔内区域采用稳态解析计算模型，钻孔外土壤区域采用有限容积法。研究了埋管出口流体温度、钻孔瞬时平均壁温、单位长度吸热量以及距钻孔一定距离处土壤温度分布随运行时间的变化规律。计算结果为地源热泵系统的动态模拟、优化设计及改进提供了参考。
Abstract：
Studies the transient heat transfer characteristic with numerical calculation method and analytic solution. Divides the calculation area into two parts based on the boundary of borehole wall, the calculation method is steady analytic solution for the area in the borehole, and the finite volume method for the soil area. Obtains the variety patterns of outlet water temperature, transient borehole wall temperature, heat exchange capacity per length and temperature distribution in certain distances from the pipe. The result can be used as a reference for the dynamic simulation, optimum design and improvement of GSHP.
Keywords:ground-sourceheatpump,U-typeburiedpipe,variableheatflowboundary,transientheattransfer,analyticsolution,numericalcalculation