蛇形微通道内绝热和沸腾流动气液两相压降的实验研究

Adiabatic and Boiling Liquid-vapor Flow Pressure Drop in a Serpentine Microchannel

蛇形微通道因结构紧凑和换热能力强的特点在高新技术领域中具有较大的研究价值,目前对微细尺度蛇形通道内全流型演变过程中的压降研究分析相对较少。通过实验的方法研究了当量直径为0.65 mm和弯管段曲率半径为1.2、1.8、2.4 mm的蛇形微通道内绝热流动和沸腾流动气液两相压降变化规律。根据实验计算了质量流速为600 kg/(m^(2)·s)时压降的占比情况,分析了质量流速为600、1200、1800、2400 kg/(m^(2)·s)时压降的变化情况,并与文献中压降经验关联式进行对比,发现文献中大部分已有关联式并不适用于蛇形微通道内气液两相流型的预测。

Serpentine microchannel heat exchangers have extensive application potential owing to their compact structures and high heat-transfer coefficients.Existing studies on two-phase flow in serpentine channels have mostly used conventionally sized channels and focused on their curved sections.The analysis of the two-phase-flow pressure drop in serpentine microchannels cannot provide a complete theoretical explanation for practical applications.In this study,two-phase pressure drop in a serpentine microchannel with a hydraulic diameter of 0.65 mm and curvature radii of 1.2 mm,1.8 mm,and 2.4 mm is experimentally investigated.Based on the experimental results,the proportion of pressure drop is calculated when the mass flow rate is 600 kg/(m^(2)·s).The pressure drop changes were analyzed at mass flow rates of 600 kg/(m^(2)·s),1200 kg/(m^(2)·s),1800 kg/(m^(2)·s),and 2400 kg/(m^(2)·s).Experimental data were compared with existing empirical two-phase-flow pressure-drop correlations;however,they showed poor agreement.