水平单管传热性能试验台设计与试验研究

基于测量单管换热性能的目的,设计一个以R134a为制冷剂,用于进行满液蒸发、管外冷凝与降膜蒸发试验研究的水平单管换热性能测试试验台,并介绍其系统原理和流程。通过光管蒸发、光管冷凝的验证性试验和重复性试验,进行管内和管外换热系数测试值与理论计算值的误差分析,并研究降膜蒸发工况制冷剂流量对换热系数的影响。试验结果表明:测试值与理论计算值的偏差均在要求范围内,试验台可以为试验研究提供准确、可靠的数据。

Design of test stand for heat transfer performance of horizontal single-tube and its experimental study

In order to measure the heat transfer efficiency of the single-tube, a test stand is designed for experimental study on flooded evaporation, tube condensing and falling-film evaporation using R134a. The system principle and experimental process are also introduced. Through the verification tests and repeating tests on the smooth tube evaporation and condensation, the deviations between test values and theoretical calculation values of heat transfer coefficient both inside and outside the tube are analyzed. The influences of refrigerant flow on the heat transfer coefficient at falling-film evaporative condition are also studied. The test results show that the deviations between the test values and the theo- retical calculation values are within the required scope. It means the test stand can provide accurate and reliable data for experimental research.