| 摘要: |
| 实验选用表面传热系数为评价指标，对外径为6.35 mm微肋管内R134a两相流动冷凝换热特性进行研究，除了分析水力工况、测试管结构参数等对管内表面传热系数的影响进行外，实验还选用Cavallini et al.关联式、Miyara et al.关联式和Oliver et al.关联式对微肋管内表面传热系数进行预测，发现Cavallini et al.关联式对微肋管内换热性能的预测能力最好，关联式预测值与实验值的平均误差、标准误差分别为﹣21.47%和21.94%；虽然Miyara et al.关联式预测值与实验值的平均误差、标准误差分别为16.21%、30.65%，但两者之间的误差范围为﹣47.12%~82.32%，说明在部分工况下Miyara et al.关联式对管内换热性能的预测仍存在较大误差；三个关联式中，Oliver et al.关联式的预测能力最差，预测值与实验值之间平均误差高达-54.93%，因此，实验根据现有实验数据对Oliver et al.关联式进行了修正，修正Oliver et al.关联式对管内换热性能的预测能力大大提高，预测值与实验值的平均误差、标准误差分别为﹣2.37%和10.77%。 |
| 关键词: 微肋管 R134a 流动冷凝换热 表面传热系数 压降 修正关联式 |
| DOI： |
| Received:February 08, 2018Revised:March 19, 2018 |
| 基金项目:上海市动力工程多相流动与传热重点实验室 (13DZ2260900) 项目资助。 |
|
| Improvement of Computational Correlation of R134a Flow Condensation Heat Transfer Characteristics inside a Micro-fin Tube |
|
Li Qingpu, Tao Leren, Wu Shengli, Mao Shushi, Zhang Danting
|
| (School of Energy and Power Engineering, University of Shanghai for Science and Technology) |
| Abstract: |
| In this study, the surface heat transfer coefficient was selected as the evaluation index and the two-phase flow condensation heat transfer characteristics of R134a inside a horizontal micro-fin tube with 6.35 mm outer diameter were studied. The effects of the test conditions and structural parameters of the micro-fin tube on the surface heat transfer coefficient were analyzed. Correlations of Cavallini et al., Miyara et al., and Oliver et al. were also applied to predict the surface heat transfer coefficient inside the micro-fin tube. We found that the correlation of Cavallini et al. was the most effective at predicting the heat transfer characteristics, where the average and mean deviations of predicted and experimental values were ﹣21.47% and 21.94%, respectively. Although the average and mean deviations of the predicted and experimental values of the correlation of Miyara et al. were 16.21% and 30.65%, respectively, the margin of deviation was ﹣47.12% to 82.32%, which indicates that a greater deviation still exists between the predicted and experimental values under certain conditions for the correlation of Miyara et al.. The predictive ability of the correlation of Oliver et al. was the worst of the three correlations, where the average deviation of the predicted and experimental values was ﹣54.93%. The correlation of Oliver et al. was thus modified based on the experimental data, and its predictive ability was improved greatly, where the average and mean deviations of the predicted and experimental values were ﹣2.37% and 10.77%, respectively. |
| Key words: micro-fin tube R134a flow condensation heat transfer surface heat transfer coefficient pressure drop modified correlation |
