Heat transfer and pressure drop during condensation of R152a in circular and square microchannels
Heat transfer and pressure drop during condensation of R152a in circular and square microchannels
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DOI：
10.1016/j.expthermflusci.2013.01.002
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发表时间：
2013-05
影响因子：
3.2
通讯作者：
Na Liu;Junming Li;Jie Sun;Hua Sheng Wang
中科院分区：
文献类型：
--
作者：
Na Liu;Junming Li;Jie Sun;Hua Sheng Wang
本文报道了R152 a在水力直径分别为1.152mm和0.952mm的圆形和方形微通道内凝结换热和压降的实验数据。饱和温度为40°C和50°C，质量通量为200至800 kg/m2 s，蒸汽质量质量为0.1至0.9。研究了质量流量、蒸汽干度和通道几何形状对传热和压降的影响。结果表明，传热系数和压降均随质量流量和干度的增大而增大，随饱和温度的增大而减小。在低质量流量下，通道几何形状对换热影响较大，而对压降影响不大。目前的数据进行了比较，早期的经验相关性和理论解决方案。圆形和方形微通道的传热系数在实验误差范围内与几个相关性和理论解一致。一个压降相关性低估了两个微通道的数据，而另一个压降相关性高估了方形微通道的数据。
The paper reports experimental data for heat transfer and pressure drop during condensation of R152a in circular and square microchannels with hydraulic diameters of 1.152mm and 0.952mm, respectively. Saturation temperatures are 40°C and 50°C with mass fluxes varying from 200 to 800kg/m2s and vapor mass qualities from 0.1 to 0.9. Effects of mass flux, vapor mass quality and channel geometry on heat transfer and pressure drop were investigated. The results show that heat-transfer coefficients and pressure drop both increase with increasing mass flux and vapor mass quality while decrease with increasing saturation temperature. Channel geometry has much effect on heat transfer at low mass fluxes while has little effect on pressure drop. The present data were compared with earlier empirical correlations and a theoretical solution. Heat transfer coefficients agree within experimental error with several correlations and a theoretical solution for both circular and square microchannels. One pressure drop correlation underestimates the data for the two microchannels while another pressure drop correlation overestimates the data for the square microchannel.