Pool Boiling of R514A, R1224yd(Z), and R1336mzz(E) on a Reentrant Cavity Surface; Extensive Measurement and Analysis

Abstract

This paper quantifies the pool boiling performance of R514A, R1224yd(Z), and R1336mzz(E) on a flattened, horizontal Turbo-ESP surface for airconditioning applications for heat fluxes between roughly 10 kWm-2 and 100 kWm-2. R514A, R1224yd(Z), and R1336mzz(E) are replacements for R123 and R245fa. All of these replacement refrigerants had measured boiling heat fluxes that were larger than that for R123 for most heat fluxes. For example, for heat fluxes between 10 kWm-2 and 80 kWm-2 , R514A, R1224yd(Z), and R1336mzz(E) exhibited average heat fluxes that were 30 %, 57 %, and 13 % larger than that for R123 for a saturation temperature of 277.6 K. For the same comparison done at a saturation temperature of 298.2 K, the average heat flux for R514A was roughly 43 % larger than that for R123. A pool boiling model, that was previously developed for pure and mixed refrigerants on the Turbo-ESP surface, was compared to the measured boiling performance. The model predicted the measured superheats of the mixed refrigerants and the single component refrigerants to within ± 0.7 K and ± 0.45 K, respectively.