摘要
Channel structure has a significant effect on the heat transfer performance of PCHE.In this study,a set of rectangular straight channel PCHEs with different cross-section aspect ratios had been tested on S-CO_(2) heat transfer experimental platform,the effect of mass flow rate in both cold and heat sides,as well as the cross-section aspect ratio of the rectangular straight channel,on the heat transfer performance of PCHE was investigated.The results show that the comprehensive heat transfer performance of the rectangular cross-section is better than that of the semicircular cross-section;increasing the aspect ratio can improve the comprehensive heat transfer performance of PCHE,but the strengthening effect diminishes as the aspect ratio increases.Increasing the mass flow rate on both sides not only enhances the pre-cooler's cooling capacity and heat transfer,but also raises the pressure drop.In addition,an improved heat transfer correlation for rectangular cross-section PCHE was proposed,considering the effects of cross-sectional aspect ratio and pseudo-critical temperature is proposed in the range of Re from 3169 to 48474 and Pr from 0.98 to 12.5,the fited results better predict the local Nu and f magnitudes and trends in the pre-cooler under different cooling conditions,outperforming the simulated data and Gnielinski and Blasius correlation.
基金
supported by the National Natural Science Foundation of China(52276150).
