HFO1234yf vaporisation inside a brazed plate heat exchanger

This paper presents the experimental heat transfer coefficients measured during HFO1234yf vaporisation inside a small brazed plate heat exchanger (BPHE): the effects of heat flux, saturation temperature (pressure) and outlet conditions are investigated. The experimental tests have been carried out at three different saturation temperatures (10, 15 and 20°C) and four different evaporator outlet conditions (vapour quality around 0.80 and 1.00, vapour super-heating around 5 and 10°C. The heat transfer coefficients show great sensitivity to heat flux and outlet conditions and weak sensitivity to saturation temperature (pressure). The saturated boiling experimental heat transfer coefficients are compared with two well-known equations for nucleate boiling, Cooper (1984) and Gorenflo (1993): the mean absolute percentage deviation between calculated and experimental data is 8.6 and 12.9% for Cooper and Gorenflo correlation respectively. HFO1234yf heat transfer coefficients are similar to those of HFC134a measured during vaporisation inside the same BPHE under the same operating conditions.