Experimental Investigation on Flow Boiling Heat Transfer and Pressure Drop of a Low-GWP Refrigerant R1234ze(E) in a Horizontal Minichannel

To protect the environment, a new low-GWP refrigerant R1234ze(E) was created to substitute R134a. However, its flow boiling performances have not received sufficient attention so far, which hinders popularization some extent. In view of this, an experimental investigation carried out in 1.88 mm horizontal circular minichannel. The saturation pressures were maintained at 0.6 and 0.7 MPa, accompanied by mass flux within 540–870 kg/m2 s heat 25–65 kW/m2. For nucleate boiling, larger brings about transfer coefficient (HTC), while for convective vapor quality appear take lead role. threshold different mechanisms is around 0.4. Additionally, pressure results large HTC. As frictional drop (FPD), it positively influenced quality, negatively affected pressure, influence negligible. Furthermore, with measured data, several existing correlations are compared. indicate that Saitoh et al. (2007) Müller-Steinhagen Heck (1986) perform best on HTC FPD mean absolute deviations 5.4% 10.9%.