小型叠板式换热器传热与流阻特性实验

Experimental investigation on heat transfer and flow resistance of miniature laminate-plate heat exchanger

研究了一种小型叠板式换热器,它由多块紫铜薄板叠合而成,薄板表面加工有2个分布腔和微通道阵列,微通道采用精密铣削加工。通过实验研究不同流速下微通道深度、分布腔形状以及换热器放置方式对传热、流阻和综合性能的影响。结果表明,传热体积是决定单位体积传热系数大小的首要因素,在传热体积相等情况下,单位体积换热面积是决定单位体积传热系数大小的主要因素。在3种影响因素中,微通道深度对换热性能影响较大,微通道深度为1 mm的换热器传热性能比深度为2 mm的提高了30%～60%;换热器放置方式对流阻和综合性能影响较大,换热器入口放置在下端时压力损失比放置在上端时下降约26%,综合性能则提高了约30%。

A miniature laminate-plate heat exchanger was developed. The heat exchanger included multiple red copper plates, with two distribution chambers and microchannel array on the surface. Microchannels were machined by precise milling. The influences of microchannel depth, chamber shape and the orientation of heat exchanger on the heat transfer, flow resistance and comprehensive performance of heat exchanger were investigated by experiments. The result indicated that the magnitude of heat transfer-volume dominated the magnitude of heat transfer coefficient per unit volume, and the magnitude of heat transfer area per unit volume determined the magnitude of heat transfer coefficient per unit volume with the same magnitude of heat transfer volume. The microchannel depth showed more influence on the heat transfer performance, and the heat transfer performance of heat exchanger with I mm deep microchannels was improved by about 30%-60% than that of the heat exchanger with 2 mm deep microchannels. The orientation of heat exchanger greatly influenced flow resistance and comprehensive performance. Pressure drop decreased by about 26% and the comprehensive performance was improved by about 30% when the inlet of the heat exchanger was placed below.