汽车空调管带式蒸发器模型参数数值模拟分析

Simulation Analysis on Distributed Parameter of Serpentine Evaporator in Automobile Air-conditioner With Mathematical Model

在湿工况下对管带式蒸发器进行了制冷剂侧和空气侧性能实验,还利用模型进行了管带式蒸发器性能的研究.制冷剂侧的研究表明:管带式蒸发器管内参数分布极不均匀,采用传统的集中参数模型计算很不合理.空气侧通过研究百叶窗角度对换热和压降的影响,改进了原有的翅片结构.相比原翅片,改进后的翅片空气侧表面传热系数提高在21%以上,但压降仅增大不到4.5%.该模型不仅合理可靠,而且具有较高的准确度.研究结果对汽车空调厂商在设计同类型产品时具有一定参考价值.

A new distributed parameter model of control volume scheme has been developed for different phase regions of the in-tube refrigerant flow, and the mathematical model was tested under changeable air flow rate in wet condition on refrigerant-side and air-side. Finally the model was used to analyze the performance of serpentine evaporator. The research on refrigerant-side shows that the parameters, including coefficient of heat transfer, temperature and pressure, change strongly in flow direction in non-uniform condition. By analyzing the effect of louver and angle on air-side heat transfer and pressure drop, a new type of louver fin is designed with an approximately 21% increase in heat transfer coefficient and only 4.5% increase in pressure drop compared with the present louver fin. It testifies that the model is not only reasonable and reliable, but also upper veracity.