纳米制冷剂在微通道内两相摩擦压降实验研究

Experimental study of two-phase fractional pressure drop of nanorefrigerant through microchannels

分别以质量分数为0.2%、0.5%、0.8%的Al2O3-R141b纳米制冷剂与纯制冷剂R141b为实验工质,在截面尺寸为1 mm×2 mm的矩形微通道内进行实验,研究流动沸腾过程中两相摩擦压降。将两相摩擦压降的实验值与5种分相模型预测值进行对比,Qu-Mudawar模型预测值和实验值最为吻合,平均绝对误差为21.4%,Chishiolm模型预测效果最差,平均绝对误差为42.5%。结合实验数据在Qu-Mudawar模型基础上进行修正,得到的修正关联式能较好的预测实验两相摩擦压降,平均绝对误差降为11.3%。

Two phase frictional pressure drop of flow boiling in rectangular microchannels with a cross section dimensions of lmm x 2mm was experimentally investigated. The working fluids were pure refrigerant R141 b and A1203-R141b nanorefrigerant （mass fraction = 0.2% ,0.5% ,0.8% ）. The experimental calcu- late values were compared with predicted values of five different separated flow models＇ correlations respec- tively. Qu-Mudawar＇ s correlation had the best predict ability, the mean absolute error was 21.4%. Mean- while, Chishiolm＇ s correlation had the worst performance, the mean absolute error was 42.5%. Based on Qu-Mudawar＇ s correlation and experiment data, a modified correlation was got and had a better predict a- bility, the mean absolute error decreased to 11.3%.