U型管换热性能影响因素研究

Study on Influence Factor of Heat Transfer Performance of the U-tube

建立了钻井单位井深换热量与钻井深度、流量变化关系的计算模型.通过实例计算,分析了在流量不变时钻井的单位井深换热量随钻井深度的变化以及50 m,100 m,150m和200 m钻井单位井深换热量随流量的变化.得出在设计地源热泵地下换热器时,需要合理的选择钻井深度、U型管内的流体流量来保证钻井的换热经济性.最后提出单位井深换热成本指数作为U型管换热经济性评价指标.

A mathematic model for the relationship between the rate of heat transfer per meter borehole and the depth of borehole as well as the flow rate was built.The change of the rate of heat transfer per meter borehole according to the depth of borehole was analyzed.The change of the rate of the heat transfer according to the flow as the borehole depth being 50 meters,100 meters,150 meters and 200 meters was also analyzed.Thus,when designing the geothermal heat exchanger,the depth of borehole and the flow rate and the inlet water temperature of U-tube should be reasonably chosen to guarantee the economy of heat transfer of the borehole.Finally,the cost of the transfer heat rate per unit borehole depth was proposed as the economic evaluation standard of U-tube heat transfer.