微尺度换热器的研究及相关问题的探讨

本文对微风度换热器产生的背景、研究现状及存在的问题进行了综述和初步分析。对在微小槽道内流体的流动和传热与常规尺度下的差异的原因和机理进行了简单分析。发现有些用气体所做的实验研究，很有可能是处于有速度滑移和温度跳跃的滑流区。速度滑移和温度跳跃致使阻力系数减小、传热减弱。对微小槽道和多孔介质对传热的强化效果进行厂比较。多孔介质对传热的强化效果更好，但同时压力损失也更大。

MICRO HEAT EXCHANGER AND RELEVANT PROBLEMS

A preliminary summary analysis of the development background ,present research state and existing problems of micro heat exchangers is reported in this paper. A preliminaryanalysis is presented to explain the causes and mechanisms that result in different fluid flowand heat transfer characteristics in micro channels as compared to ordinary size channels.It is found that some experimental research on convective heat transfer using gases was probably in the regime having velocity slip and temperature jump, which cause the frictionfactor and heat transfer coefficient to decrease. Comparison of the enhancement effect ofheat transfer using micro channels or porous media shows that porous structures are moreeffective, but with much larger pressure drop. Efficient micro heat exchanger can be madeusing porous media.