在热流密度3.54 W.cm-2到40.7 W.cm-2,雷诺数由278到6502,出口干度0到1的工况范围内对R134a在微尺度单通道和多通道内流动沸腾压降特性进行了可视化实验研究.在相同工况时,单通道压降小于多通道压降;随热流密度和出口干度的增加,多通道压降增长范围小于单通道压降增长范围.通过可视观察,多通道内流动沸腾不稳定流动现象较单通道更为明显,并且多通道平均压降和实时压降波动范围更大.结合可视实验观察,多通道内压降高于单通道压降的主要原因为不稳定流动现象造成,并对产生不稳定流动的因素和造成压降升高的原因进行了分析.“,”The pressure drop characteristics of R134a flow boiling in micro scale single and multi-channels were investigated.The heat flux ranged from 3.54 W·cm-2 to 40.7 W·cm-2,Reynolds number varied from 278 to 6502,and vapor quality in outlet was at the range of 0 to 1.At the same experimental conditions,pressure drop in single channel was lower than that in multi-channels.With the increase of heat flux and mass flux rate,the pressure drop range in multichannel was lower than that in the single channel.With visual observation,flow instability was the main reason for higher pressure drop in multichannels.The reasons for flow instability and high pressure drop were analyzed.