Heat transfer during evaporation of R1234ze(E), R32, R410A and a mixture of R1234ze(E) and R32 inside a horizontal smooth tube

This experimental study measured and compared the heat transfer coefficients during in-tube evaporation of R1234ze(E), R32, the nearly azeotropic HFC refrigerant blend R410A and a zeotropic mixture R1234ze(E)/R32 (55/45 mass %) inside a water heated double tube heat exchanger. The experiment has been carried out under the conditions of mass flux varying from 150 to 445 kg m−2 s−1, the saturation temperatures are 5 and 10 °C, over the vapor quality range 0.0–1.0. The effect of vapor quality, mass flux and saturation temperature on heat transfer coefficients have been analyzed. It is found that the experimental heat transfer coefficients of R1234ze(E) are lower than R1234ze(E)/R32 (55/45mass%), R410A and R32 by 11%, 56% and 83%, respectively, at about 0.48 vapor quality and 300 kg m−2 s−1 mass velocity. Experimental results have been compared with some well-known correlations.

► We have measured evaporation heat transfer coefficient of R1234ze(E) and R1234ze(E)/R32.
► The experimental results were compared with conventional refrigerants R32 and R410A.
► Heat transfer coefficients have been predicted by some well-known correlations.