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.