Experimental investigation on saturated critical heat flux of refrigerant R134a at high saturation temperatures

This article presents saturated critical heat flux results in an aluminium heat sink at high saturation temperatures. The test section is made up of seven rectangular mini-channels that are 1.0 mm deep and 2.0 mm wide, with a heated length of 25 mm. R134a has been used as the working fluid. The effect of mass flux G (ranging from 150 up to 330 kg/m2 s) has been investigated. All tests have been performed at medium to high saturation temperatures, ranging from 25 °C up to 70 °C. The experimental results showed that the saturation temperature had only a mild influence on the CHF, at each mass flux imposed. On the contrary, when increasing the mass flux at a given saturation temperature, the critical heat flux was observed to increase significantly. Finally, the prediction capability of a well-known critical heat flux correlation has also been tested.