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Study on comprehensive performance evaluation for condensation heat transfer inside the micro-fin tube

To develop a comprehensive performance evaluation model of heat transfer tube, the flow condensation heat transfer experiment of R1234yf inside the tube was operated. In this article, the effect of mass flux, condensation temperature, and fin structural parameters on the heat transfer characteristics was studied, and then corrections of heat transfer coefficient and pressure drop predictive effect were checked. Results show that the heat transfer coefficient and pressure drop increase with increasing mass flux and condensation temperature, and the heat transfer enhanced ratio is 2.53∼3.67 while the pressure drop deterioration ratio was 1.95∼2.49 for the micro-fin tube; the Yu and Koyama correlation has a best predictive effect for the heat transfer coefficient with the average and mean deviation of 0.77% and 10.84%, and the Han et al. correction shows the best predictive effect for the pressure drop with the average and mean deviation of 1.82% and 6.23%. Finally, the heat transfer coefficient per unit pressure drop was selected as evaluation index of heat exchanger comprehensive performance, a model was developed based on the Yu and Koyama correlation, and it can predict the heat transfer coefficient per unit pressure drop with a mean absolute prediction error of −1.65%.