Pool Boiling of Low-Global Warming Potential Replacements for R134a on a Reentrant Cavity Surface

Abstract

This paper quantifies the pool boiling performance of R134a, R1234yf, R513A, and R450A on a flattened, horizontal reentrant cavity surface. The study showed that the boiling performance of R134a on the Turbo-ESP exceeded that of the replacement refrigerants for heat fluxes greater than 20 kWm−2. On average, the heat flux for R1234yf and R513A was 16 % and 19 % less than that for R134a, respectively, for R134a heat fluxes between 20 kWm−2 and 110 kWm−2. The heat flux for R450A was on average 57 % less than that of R134a for heat fluxes between 30 kWm−2 and 110 kWm−2. A model was developed to predict both single-component and multi-component pool boiling of the test refrigerants on the Turbo-ESP surface. The model accounts for viscosity effects on bubble population and uses the Fritz (1935) equation to account for increased vapor production with increasing superheat. Both loss of available superheat and mass transfer resistance effects were modeled for the refrigerant mixtures. For most heat fluxes, the model predicted the measured superheat to within ± 0.31 K.

Effect of IF-WS2 nanolubricant on R134a boiling on a reentrant cavity surface:

“…4. The Kedzierski et al (2018) data are within 10 % of most of the present measurements. The Gorgy (2016) measured heat flux is roughly 30 % less than the present measurements.…”

“…From the confidence intervals, the expanded uncertainty of the estimated mean wall superheat was, on average, 0.05 K. Table 5 provides the average magnitude of the 95 % multi-use confidence interval for the fitted wall superheat for all of the test data. The R134a pool boiling measurements of Gorgy (2016) and Kedzierski et al (2018) for the Turbo-ESP surface are shown as dashed lines on Fig. 4.…”

Pool boiling of HFO-1336mzz(Z) on a reentrant cavity surface; extensive measurement and analysis

“…The following describes an improvement to the pool boiling model for the Turbo-ESP surface that was developed in Kedzierski et al (2018). The improvement was mainly achieved by including the present boiling measurements along with the Kedzierski et al (2018) measurements to expand the validity of the model. The original model includes an adjustment for refrigerant mixtures that is not modified here because it a multiplicative correction factor that is expected to remain valid.…”

“…The boiling heat transfer for R1233zd(E) was 19% greater than that for R123. Kedzierski et al (2018) quantified the pool boiling performance of R134a, R1234yf, R513A, and R450A on a flattened, horizontal Turbo-ESP surface. Their study showed that the boiling performance of R134a on the Turbo-ESP exceeded that of the replacement refrigerants for heat fluxes greater than 20 kWm -2 .…”

“…Because of the relatively recent introduction of R1336mzz(Z), the availability of measured pool boiling heat transfer data given in the literature is limited for this refrigerant. Only two studies for the Turbo-ESP surface (Gorgy (2016) and Kedzierski et al, 2018), which did not include the performance of R1336mzz(Z), exist in the literature. Consequently, the present study provides pool boiling heat transfer measurements for R123, and R1336mzz(Z) on the horizontal, flat, copper, Turbo-ESP-finned surface for test conditions that are applicable for air-conditioning applications.…”