热泵热水器螺旋套管冷凝器中R22的凝结换热性能

西安科技大学 能源学院,陕西 西安 710054

螺旋环形空间; 凝结换热; 换热系数

Condensation heat transfer performance for R22 flowing in spiral tube-in-tube condenser of heat pump water heater
ZHANG Xiao-yan,HONG Shan-hu

(College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

spiral annular space; condensation heat transfer; heat transfer coefficient

DOI: 10.13800/j.cnki.xakjdxxb.2015.0510

备注

螺旋套管换热器因其优越的结构特性和高效的换热效率在热泵系统中得到了广泛应用,本文通过实验方法对螺旋套管冷凝器中R22的凝结换热性能随制冷剂干度、进水温度、进水流量的变化情况进行了测试,得到R22的凝结换热系数随制冷剂干度、进水温度、进水流量的变化关系。结果 表明:R22的凝结换热系数随干度的减小而增大。R22的凝结换热系数随进水温度的升高而减小,进水流量为0.4 m3/h时,当进水温度由17 ℃上升至34 ℃,R22的凝结换热系数由3 346 W·m-2·k-1减小至3 002 W·m-2·k-1.R22的凝结换热系数随进水流量的增大而增大。当进水温度为17 ℃时,进水流量由0.4 m3/h增至0.53 m3/h,R22的凝结换热系数由3 346 W·m-2·k-1增至4 168 W·m-2·k-1.通过对文献中制冷剂在相似流动通道内换热关系式进行合理修正,计算得到R22在螺旋环形通道内的凝结换热系数,并与实验结果进行比较。

Because of their superior structure property and high heat exchange efficiency, spiral tube-in-tube heat exchanger are widely used in heat pump system.The variation of heat transfer coefficient with refrigerant dryness,inlet water temperature,water flow rate for R22 condensing in spiral tube-in-tube condenser was experimentally tested, and the relationship of heat transfer coefficient with refrigerant dryness,inlet water temperature,water flow rate was obtained. The results indicate:the condensation heat transfer coefficient of R22 increases with the decrease of the dryness.Condensation heat transfer coefficient of R22 decreases with the increase of inlet water temperature, when water flow rate is 0.4 m3/h, Condensation heat transfer coefficient of R22 decreases from 3 346 W·m-2·k-1 to 3 002 W·m-2·k-1 with inlet water temperature increasing from 17 ℃ to 34 ℃. Condensation heat transfer coefficient of R22 increases with the increase of water flow rate, when inlet water temperature is 17 ℃,condensation heat transfer coefficient of R22 increases from 3 346 W·m-2·k-1 to 4 168 W·m-2·k-1 with water flow rate increasing from 0.4 m3/h to 0.53 m3/h. And condensation heat transfer coefficient of R22 in spiral annular space was calculated by correlation for similar passage in literature,which was modified according to the actual condition in this study, the calculations were compared with the experimental results.