小通道钎焊板式冷凝器性能仿真与实验研究

Simulation and Experimental Study on Performance of a Mini-channel Brazed Plate Condenser

本文针对当量直径为1.5 mm的小通道钎焊板式冷凝器的换热和压降特性进行了仿真和实验研究。采用有限体积法建立了一维稳态分布参数模型,对R134a和R1234yf两种制冷剂在板间冷凝换热的性能进行仿真模拟,并对模型进行了实验验证。实验结果表明:本文所建立的仿真模型精度较高,换热性能平均误差为4%,压降平均误差为16%,可用于分析换热器的整体性能。最后用此模型仿真对比了R134a和R1234yf在小通道钎焊板式换热器内的冷凝换热特性,结果显示,在相同工况下,用R1234yf替代R134a,传热系数平均下降9%,压降平均下降8%。

Nowadays,miniaturization is a feasible course of action in the development of brazed plate heat exchangers.In this study,a mini-channel brazed plate condenser with an equivalent diameter of 1.5 mm was studied.The heat transfer and pressure drop characteristics were analyzed.First,a one-dimensional steady-state distribution parameter model was established by the finite volume method to compute the condensation performance of R134a and R1234yf.Second,an experiment was conducted to confirm the reliability of the simulation model.According to the experimental results,the simulation model has high precision.The average error of the heat transfer performance predicted by the model is 4%,and the average error of pressure drop predicted by the model is 16%.Finally,the simulation model was used to calculate the condensation heat transfer characteristics of R134a and R1234yf in the mini-channel brazed plate heat exchanger.The simulation results show that the heat transfer performance and pressure drop of R1234yf are 9%and 8%lower than that of R134a under the same condensation conditions.