In this paper

a boiling heat transfer test unit was designed and built

while the characteristics of boiling heat transfer of refrigerant in a single microtube was researched. The wall temperature of microtube was measured by TH5104 infrared thermography. The test piece was a single stainless circular tube whose external diameter (do) was 1.22mm

internal diameter (di) was 0.86mm

and length was 200mm. The infrared photography tested and recorded the wall temperature of the microtube with heat flux ranging from 65kW/m2 to 231kW/m2 at different mass flux from 1726kg/m2.s to 8635kg/m2.s. Experimental results were analyzed and discussed. The wall temperature distribution along the axial direction varies obviously. For the flow boiling in horizontal microtube

there was a large temperature difference along the whole tube during the evaporation of fluid in micro tube. Whether the difference of wall temperature is positive or negative is relative to the heat flux. And the variation of the wall temperature was affected by the heat flux

flow patterns of working fluid and heat transfer model. The more complex the flow pattern is

the more severely the wall temperature varies.