微管换热器流动与传热的实验研究

An Experimental Study on Heat Transfer and Fluid Flow in a Microtube Heat Exchanger

本文对自制微管换热器的流动与传热性能进行了实验研究。提出了微细圆管换热器管内单相强制对流换热努摩尔数准则式,并与已有相关文献提出的关联式做了对比,结果表明:微管管内换热系数比常规尺度计算公式预测值要高,同时本文分析了微细管内的压力降、摩擦阻力系数f随雷诺数的关系。研究表明微管管内压降、摩擦系数都比常规尺度预测值要高。

A micro-sized shell and tube heat exchanger （MTHE） was fabricated, and its performance in heat transfer and fluid flow was experimentally studied. The single-phase forced convection heat transfer correlation in the tube side of the MTHE was proposed. An assessment of the experimental results was performed by comparing the obtained experimental data with the others in the previous literature. It is shown that the averaged Nusselt number is much higher than that of the conventional sized heat exchanger. In the Reynolds number range of this study, the pressure drop and friction coettleients were found to be considerably higher than those predicted by the conventional correlations.