流速对垂直双U形地埋管换热器热交换的影响

The effect of fluid velocity on heat transfer of vertical double U-tube heat exchanger

针对设计地源热泵室外侧换热器时钻孔间距过大会浪费土地资源,过小又会导致土壤温度持续变化、降低换热效果的问题,通过建立系统运行费用函数,研究了系统连续运行30 d时模拟流速对热力半径的影响.结果显示,0.4 m/s时,热力半径达到0.95 m,随着流速的增大,热力半径增大,在流速>0.6 m/s时,热力半径增幅明显减少.

It is necessary to determine a reasonable bore distance when we design the outdoors heat exchanger of the ground-coupled heat pump. The larger distance will cause the waste of ground source, on the contrary, it will change the soil temparature and reduce the efficiency of heat exchanger. So, the effect of fluid velocity on thermal radius was simulated through builting the system runing cost function when sys- tem had worked 30 d. The computational results showed that thermal radius is 0.95 m when fluid velocity is 0.4 m/s, which increases with increasing fluid velocity. But the thermal radius range is obviously slight when fluid velocity is more than 0.6 m/s.