结霜工况下微通道蒸发器制冷剂分布特性

为研究结霜对微通道蒸发器内制冷剂分布特性的影响,本文提出了一种制冷剂分布参数(RDP)的评定方法。采用红外热成像及数字图像处理技术,测量结霜工况下微通道蒸发器内制冷剂分布。结果表明:随着蒸发器表面霜层厚度的增加,蒸发器内过热区逐渐缩小,两相区制冷剂分布更加均匀。实验180 min时比实验60 min时制冷剂过热区缩小22.7%,RDP提高17.2%,换热量降低2.34%。研究结果为结霜工况下微通道蒸发器制冷剂分布特性提供了定量测量方法。

Distribution Characteristics of Refrigerant in Micro-channel Evaporator under Frosting Conditions

A refrigerant distribution parameter (RDP) evaluation method is proposed to investigate the influence of frost formation on the distribution of refrigerant in micro-channel evaporators. The distribution of refrigerant under frosting conditions was measured by infrared thermal imaging and digital image processing. Experimental results showed that with an increase in thickness of the surface frost layer of the evaporator, the overheating zone in the evaporator decreased gradually and the distribution of the refrigerant in the two-phase zone was more uniform. In a 180 min experiment conducted in this study, the refrigerant overheat area decreased by 22.7%, the RDP increased by 17.2%, and the heat exchange rate decreased by 2.34%. These results provide a quantitative method to examine the distribution characteristics of micro-channel evaporator refrigerant under frosting conditions.