一种泡沫金属通道两相压降新型关联式

A New Two-Phase Pressure Drop Correlation for Metal Foam Channels

泡沫金属填充于换热器通道内能有效提高换热器两相传热性能,具有较好的应用前景,伹要求对泡沫金属通道内两相压降能够进行准确的预测,以满足工程应用中设备和系统的设计要求。本文使用了6篇文献的泡沫金属通道内两相压降实验数据,实验条件包括:泡沫金属PPI为5~40,孔隙率为0.87~95;通道水力直径为4.36~13.8 mm;质流密度为0~350 kg/(m^(2)·s);干度为0~0.8。分析了两相流因子和Lockhart-Martinelli参数的分布规律,发现两相流因子随泡沫金属孔径与通道水力直径之比减小而增大,随干度的增大而增大;当径比从0.179变为0.31时,两相流因子提升了1.37~1.52倍;当干度从0变为0.8时,两相流因子最大提升了3.41倍。同时基于Lockhart-Martinelli关联式开发了一种新型泡沫金属通道两相压降预测关联式,结果表明:新的关联式的预测值与实验数据的绝对平均误差为22%,该关联式能准确预测泡沫金属通道的两相压降。

The metal foam used for filling a heat exchanger channel can effectively improve two-phase heat transfer performance and has good application prospects.Accurate prediction of the two-phase pressure drops in the metal foam channel is required for equipment and system designs in engineering applications.It is necessary to develop a suitable method for predicting the two-phase pressure drop in metal foam channels under a wide range of conditions.The two-phase pressure drop experimental data in the metal foam channels of six references were used.The experimental conditions included metal foam pores per inch(PPI)of 5-40,porosity of 0.87-95,channel hydraulic diameter of 4.36-13.8 mm,mass flux of 0-350 kg/(m^(2)·s),and quality of 0-0.8.The distribution of the two-phase multiplier and the Lockhart-Martinelli parameter was analyzed,and it was found that the two-phase multiplier increased with a decrease in the ratio of the metal foam pore diameter to the channel hydraulic diameter and increased with an increase in the quality;when the diameter ratio changes from 0.31 to 0179,the two-phase multiplier increases by 1.37 to 1.52;and when the quality changes from 0 to 0.8,the two-phase multiplier increases by a factor of 3.41.A new correlation was developed based on the Lockhart-Martinelli correlation.The results show that the absolute average error between the predicted values and experimental data is 22%,which indicates that the new correlation can provide an accurate prediction.