含润滑油R134a在微通道内沸腾-空化耦合实验研究

Cavitation-Boiling Coupling Phenomenon Experimental Investigation of R134a Mixed With Lubricating Oil Flow in Microchannel

混入了矿物润滑油的制冷剂R134a,流经带有空化结构的微通道,发生了沸腾-空化耦合相变现象。无氧铜铜板上刻有长150 mm宽0.8 m深1 mm的微通道,微通道内置有长4 mm宽0.2mm的矩形空化结构。铜板上面覆盖有玻璃片。观察测量不同流量及不同加热量下通道内的流形及通道背面温度。实验结果表明:润滑油抑制了相变现象的发生,降低了换热效率;工作介质为混入润滑油的制冷剂时,通道背面温度远高于工作介质为纯净制冷剂时的通道背面温度。

R134a mixed with lubricating oil and pure R134a flow in micro-channel was experimentally investigated.The cavitation structure,a rectangular micro-orifice 0.2 mm wide and 4 mm long, entrenched in a micro-channel 0.8 mm wide and 1 mm deep and 150 mm long,which was engraved on an oxygen-free copper plate covered with quartz glass.Flow pattern is observed and the wall temperature along channel is measured on different mass flux and different heat flux.In the experiment,a phenomenon was observed that,to compare with pure R134a.lubricating oil inhibits the occurrence of phase transitions,and heat transfer efficiency is reduced.While the medium is mixed with the oil, temperature of the channel back wall is much higher than temperature while the medium is pure R134a.