汽车空调平流式冷凝器性能仿真分析

为分析汽车空调平流式冷凝器的换热、流动性能,假设制冷剂沿管长方向做一维流动,空气侧流动视为零维流动,忽略制冷剂加速压降,对制冷剂两相区采用均相模型.使用AMESim建立平流式冷凝器仿真模型,并通过与试验对比验证模型的准确性.改变冷凝器结构参数,分析对冷凝器的性能影响,发现合理的制冷剂回路流程布置可以改善平流式冷凝器性能;增加流程数可以增加换热量,但是压降也会增大;制冷剂侧总横截面积相等时,微通道数目增加,换热量增加;空气速度较小时,减小翅片间距可以增加换热量.

Simulation and analysis on performance of parallel flow type condenser of automotive air conditioner

To analyze flow and heat transfer performance of parallel flow type condenser of automotive air conditioner, refrigerant flow is supposed to be 1D type along tube direction, air flow is treated as zero dimension type, the refrigerant pressure drop due to acceleration is ignored, and the homogenous phase model is used in the two phase flow of refrigerant. A parallel flow type condenser model is built by AMESim, and the accuracy of the model is verified by comparing with experimental results. The structural parameters of the condenser are changed to simulate and analyze its performance. The result is that the performance could be improved with reasonable refrigerant circuit configuration. With the increase of refrigerant circuit number, heat transfer rate increases, however, the pressure drop increases too. When the total cross sectional area of refrigerant side is constant, heat transfer rate increases with the increase of micro channel number. When the air velocity is slow, heat transfer rate increases with the decrease of fin pitch.