小尺度流道换热器换热特性的实验研究

An experimental study of heat transfer characteristics in heat exchanger with miniscale channels

在单相强迫对流情况下，以当量直径为0．55mm、0．91mm、1．38mm，槽道截面形状为矩形和三角形的小尺度流道换热器为实验段，以水和乙二醇溶液为换热介质，进行实验研究，实验的威数范围为300～2500，结果表明：雷诺数相同的情况下，对流换热舰数随当量直径de的增大而增大，Pr数大的乙二醇水溶液的Nu数大于水的舰数，槽道形状对换热器的换热效果有显著影响，三角形槽道的Nu数大于矩形槽道的Nu数，小尺度流道内流体流动的临界雷诺数胁。在700～1200之间。

The experimental study of heat transfer characteristics is conducted for water and ethylene eglycol solution flowing in the heat exchanger with rectangular or triangular mini-channels with equivalent diameter of 0.55mm, 0.91mm and 1.38mm. In the experiments, the Reynolds numbers range from 300 to 2500.The experimental results show that at a fixed Reynolds number, the Nusselt number increases with the rising equivalent diameter; and the Nusselt number for ethylene glycol solution with larger Prandtl number is greater than that for water; what＇s more, the geometrical configuration of the mini-channels exerts a significant influence on the heat transfer. The critical Reynolds number from laminar flow to turbulent flow ranges from 700 to1200.