R245fa有机工质在Turbo-EHP管外流动沸腾换热实验研究

发布时间：2018-04-28 03:40

  本文选题：Rfa有机工质 + Turbo-EHP型管　； 参考：《太阳能学报》2017年05期

【摘要】：结合沸腾传热问题,通过凝练并设计实验系统,研究有机工质R245fa在高效蒸发换热管Turbo-EHP管外流动沸腾传热的性能,分析有"孔穴"结构的表面强化管的强化机理。实验中通过改变热源流量、温度以及工质流量等参数,研究其与局部以及平均沸腾换热系数之间的关系。实验结果表明,Turbo-EHP型管前、中、末3段的强化效果不同,在前段气泡热阻对换热性能有一定的影响,中段换热效果达到最优,末段由核态沸腾转为气与壁面的对流换热,换热效果减弱;且随着工质流量的增大,沸腾性能显著增强。
[Abstract]:Based on the boiling heat transfer problem, the boiling heat transfer performance of organic working fluid R245fa outside the Turbo-EHP tube was studied by condensing and designing an experimental system, and the strengthening mechanism of the surface strengthened tube with "hole" structure was analyzed. In the experiment, the relationship between the heat source flux, temperature and working fluid flow rate and the local and average boiling heat transfer coefficient was studied. The experimental results show that in the front of Turbo-EHP tube, the enhancement effect is different in the middle and the last three sections. In the front section, the bubble thermal resistance has a certain influence on the heat transfer performance, the heat transfer effect in the middle section reaches the optimum, and the final stage changes from nucleate boiling to convection heat transfer between gas and wall. The heat transfer efficiency is weakened, and the boiling performance is enhanced with the increase of the working fluid flow rate.
【作者单位】： 中低温热能高效利用教育部重点实验室天津大学机械工程学院;
【基金】：国家高技术研究发展(863)计划(2012AA053001)
【分类号】：TB64;TK124
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本文编号：1813607