微通道换热器不同风速下换热及其流动特性研究

Study on heat transfer and flow characteristics of microchannel heat exchanger under different wind speed

以微通道换热器为研究对象,搭建微通道换热器性能测试实验台,利用控制变量法研究分析不同入口风速对出口空气温度、湿度、压降、凝水生成量等参数的变化规律,计算换热器表面凝水生成速率、凝水排除速率、换热量和空气侧传热系数,从而分析表面凝排水特性及其对换热性能的影响。实验结果表明,风速对微通道换热和流动特性影响显著。出口空气温度和空气侧压降均随风速的提高而增加,压降增幅随风速的增加有所减缓。风速为2.5m/s时,换热量和空气侧传热系数最佳。

Taking microchannel heat exchanger as the research object,the performance test bench of microchannel heat exchanger was established. The influence of the inlet wind speed on outlet air temperature,humidity,pressure drop,condensate generation were studied,and surface condensate generation rate,condensate removal rate,heat transfer rate and air side heat transfer coefficient were calculated by using control variable method. Surface condensation and drainage characteristics and their effects on heat transfer performance were analyzed. The experimental results show that the influence of wind speed on the heat transfer and flow characteristics of microchannels is significant. The outlet air temperature and air side pressure drop increase with the increase of wind speed,and the increase of pressure drop decreases with the increase of wind speed. When the wind speed is 2.5 m/s,the heat transfer capacity and air side heat transfer coefficient are the best.