摘要：

在压力为0.5～1.7 MPa，质量流量为381～2291 kg·m^-2·s^-1，干度为0～1.0的工况范围内试验研究微尺度通道内低沸点混合工质R32/R134a的流动沸腾压降性能，同时对两相流流型进行可视化观察。微尺度通道内径为1.92 mm,0.86 mm和0.5 mm

关键词: 微通道, 低沸点, 流动沸腾, 压降

Abstract:

An experiment was conducted to investigate the pressure drop characteristics during flow boiling in micro-channel with low boiling point〖JP〗 non-azeotropic refrigerant mixtures of R32/R134a.The experimental conditions are chosen as follows: inlet pressure is 0.5—1.7 MPa, mass flow is 381—2291 kg·m^-2·s^-1 and vapor quality is 0—1.0.At the same time, flow pattern in the exit of micro-channel were observed by a high speed camera.The diameter of three microtubes is 1.92 mm, 0.86 mm and 0.5 mm respectively.The experimental results reveal that two-phase pressure drop rises with increasing mass flow rate.At low heat flux, two-phase pressure drop increases with increasing heat flux.The trend was different that when heat flux q>150 kW·m^-2, pressure drop kept unchanged with increasing heat flux.The diameter of micro-channel has significant effect on the two-phase pressure drop in micro-channel.There were some pressure drop fluctuations when flow pattern transited from slug to annular.Pressure drop increased slowly when flow pattern was slug and was stable when flow pattern was annular.

Key words: 微通道, 低沸点, 流动沸腾, 压降