Experimental study on flow boiling heat transfer and pressure drop in a horizontal tube for R1234ze(E) versus R600a

摘要

Highlights?Flow patterns of R1234ze(E) were recorded and analyzed.?The effects of parameters on heat transfer and pressure drop were studied.?Prediction models of heat transfer coefficient and pressure drop were evaluated.?New Prediction model for heat transfer of R1234ze(E) was developed.AbstractThis study presents flow boiling heat transfer and pressure drop characteristics of R1234ze(E) in a smooth horizontal tube with an inner diameter of 6?mm. The experiments were conducted at saturation pressures from 0.215 to 0.415?MPa, mass fluxes from 130 to 258?kg?m?2?s?1and heat fluxes from 10.6 to 74.8 kW m?2. The influences of saturation pressure, mass flux and heat flux were analyzed. Furthermore, the performance of R1234ze(E) was compared with R600a. The results show that heat transfer coefficient and pressure drop of R600a are larger than R1234ze(E). Several well-known correlations were evaluated and the results indicate that the correlation of Fang (2013) and Yang et?al. (2017) give the best fit to the heat transfer coefficient and pressure drop respectively. Finally, a new heat transfer correlation was proposed and it makes great progress in the prediction accuracy.]]>