R32 partial condensation inside a brazed plate heat exchanger

Abstract

This paper presents recent measurements of heat transfer coefficient obtained during condensation of R32 inside a commercial brazed plate heat exchanger (BPHE). The experimental data show the effect of refrigerant mass velocity, vapor quality, temperature difference (saturation-to-wall) and inlet vapor superheating. In particular, the specific mass velocity is varied between 15 and 40 kg m−2 s−1 and the outlet vapor quality between 0.0 and 0.65, while inlet vapor superheating goes from 5 to 25 K. The saturation temperature is kept constant at around 36.5°C, which can be considered a usual temperature level for water cooled heat pump applications. The present authors provide a numerical procedure to calculate the condensation heat transfer in the BPHE, accounting also for the superheating effect. This model is assessed by comparisons with the experimental measurements relative to R32, R410A, and R744

Refrigerant R32 as lower GWP working fluid in residential air conditioning systems in Europe and the USA

“…In all tests, the HTC of R32 was higher than the R410A values (higher thermal conductivity), but the pressure drop was up to 25% higher under a high-quality vapour (lower density, which implies a higher velocity). Mancin et al [47] presented an accurate model for R32 condensation for brazed plate heat exchangers and compared the results with a prototype. Considering a Tsat of 309.7 K; SH of 5, 10, 15, and 25 K; G between 15 and 40 kg m −2 s −1 ; and outlet x between 0 and 0.65, the relative deviation was 1.2% and the AAD was 4.7%.…”

A new computational procedure for refrigerant condensation inside herringbone-type Brazed Plate Heat Exchangers

“…Three different plate geometries were tested: Low (30°/30°), Medium (30°/63°), High (63°/63°). -HFC410A and HFC32 super-heated vapour condensation data by Mancin et al [7,23,24]: 61 data points for HFC410A and 103 data points for HFC32. Two different plate geometries were tested: type B and C with refrigerant mass flux from 13 to 37 kg m À2 s À1 .…”

HFC32, a low GWP substitute for HFC410A in medium size chillers and heat pumps

“…%)). Mancin et al (2013) presented HFC32 super-heated vapour condensation data inside a BPHE with refrigerant mass flux from 13 to 37 kg m À2 s À1 finding heat transfer coefficients higher than those of HFC410A and HFC407C.…”