Details
| Original language | English |
|---|---|
| Article number | 117404 |
| Journal | Applied thermal engineering |
| Volume | 197 |
| Early online date | 1 Aug 2021 |
| Publication status | Published - Oct 2021 |
Abstract
Plate heat exchangers with an enhanced surface are attracting continuous attention as a smart option to acquire a more efficient heat transfer performance. Despite of a large number of research dedicated to the two-phase heat transfer, the understanding of condensation heat transfer mechanisms is still defective. In this paper, the experimental results of the quasi-local heat transfer coefficient and the two-phase frictional pressure drop during condensation of R1234ze(E) and R134a are reported in a micro-structured plate heat exchanger with mixed plates showing a chevron angle of 27°/63° and a hydraulic diameter of 5.5 mm. The measurements were carried out with 110 groups of data for pure R1234ze(E) and 163 groups of data for pure R134a respectively. The mass flux and saturation temperature range from 34.08 to 70.64 kg/m2s, 22.51 to 40.84 °C (corresponding to psat = 4.62–7.84 bar, pr = 0.13–0.22) for R1234ze(E), and 46.39 to 77.9 kg/m2s, 24.93 to 38.03 °C (psat = 6.64–9.64 bar, pr = 0.16 – 0.24) for R134a. The effect of mass flux and saturation pressure is discussed, the experimental results indicate that the condensation in the micro-structured plate heat exchanger is shear-controlled, the transition from partial film flow to full film flow occurs at x ≈ 0.35–0.45. The characteristics of the two-phase frictional pressure drop for the mixed 27°/63° plates is similar to soft plates. Based on existing correlations, the experimental results are compared with predictive results by existing empirical correlations, and new correlations with better accuracies are developed by taking the influence of different parameters into consideration.
Keywords
- Condensation, Correlation, Frictional pressure drop, Micro-structured plate, Quasi-local heat transfer
ASJC Scopus subject areas
- Energy(all)
- Energy Engineering and Power Technology
- Engineering(all)
- Industrial and Manufacturing Engineering
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In: Applied thermal engineering, Vol. 197, 117404, 10.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Condensation quasi-local heat transfer and frictional pressure drop of R1234ze(E) and R134a in a micro-structured plate heat exchanger
AU - Wang, Ru
AU - Kabelac, Stephan
N1 - Funding Information: The author acknowledge the financial support from the China Scholarship Council (CSC) under contract No. 201708330250 .
PY - 2021/10
Y1 - 2021/10
N2 - Plate heat exchangers with an enhanced surface are attracting continuous attention as a smart option to acquire a more efficient heat transfer performance. Despite of a large number of research dedicated to the two-phase heat transfer, the understanding of condensation heat transfer mechanisms is still defective. In this paper, the experimental results of the quasi-local heat transfer coefficient and the two-phase frictional pressure drop during condensation of R1234ze(E) and R134a are reported in a micro-structured plate heat exchanger with mixed plates showing a chevron angle of 27°/63° and a hydraulic diameter of 5.5 mm. The measurements were carried out with 110 groups of data for pure R1234ze(E) and 163 groups of data for pure R134a respectively. The mass flux and saturation temperature range from 34.08 to 70.64 kg/m2s, 22.51 to 40.84 °C (corresponding to psat = 4.62–7.84 bar, pr = 0.13–0.22) for R1234ze(E), and 46.39 to 77.9 kg/m2s, 24.93 to 38.03 °C (psat = 6.64–9.64 bar, pr = 0.16 – 0.24) for R134a. The effect of mass flux and saturation pressure is discussed, the experimental results indicate that the condensation in the micro-structured plate heat exchanger is shear-controlled, the transition from partial film flow to full film flow occurs at x ≈ 0.35–0.45. The characteristics of the two-phase frictional pressure drop for the mixed 27°/63° plates is similar to soft plates. Based on existing correlations, the experimental results are compared with predictive results by existing empirical correlations, and new correlations with better accuracies are developed by taking the influence of different parameters into consideration.
AB - Plate heat exchangers with an enhanced surface are attracting continuous attention as a smart option to acquire a more efficient heat transfer performance. Despite of a large number of research dedicated to the two-phase heat transfer, the understanding of condensation heat transfer mechanisms is still defective. In this paper, the experimental results of the quasi-local heat transfer coefficient and the two-phase frictional pressure drop during condensation of R1234ze(E) and R134a are reported in a micro-structured plate heat exchanger with mixed plates showing a chevron angle of 27°/63° and a hydraulic diameter of 5.5 mm. The measurements were carried out with 110 groups of data for pure R1234ze(E) and 163 groups of data for pure R134a respectively. The mass flux and saturation temperature range from 34.08 to 70.64 kg/m2s, 22.51 to 40.84 °C (corresponding to psat = 4.62–7.84 bar, pr = 0.13–0.22) for R1234ze(E), and 46.39 to 77.9 kg/m2s, 24.93 to 38.03 °C (psat = 6.64–9.64 bar, pr = 0.16 – 0.24) for R134a. The effect of mass flux and saturation pressure is discussed, the experimental results indicate that the condensation in the micro-structured plate heat exchanger is shear-controlled, the transition from partial film flow to full film flow occurs at x ≈ 0.35–0.45. The characteristics of the two-phase frictional pressure drop for the mixed 27°/63° plates is similar to soft plates. Based on existing correlations, the experimental results are compared with predictive results by existing empirical correlations, and new correlations with better accuracies are developed by taking the influence of different parameters into consideration.
KW - Condensation
KW - Correlation
KW - Frictional pressure drop
KW - Micro-structured plate
KW - Quasi-local heat transfer
UR - http://www.scopus.com/inward/record.url?scp=85112054374&partnerID=8YFLogxK
U2 - 10.1016/j.applthermaleng.2021.117404
DO - 10.1016/j.applthermaleng.2021.117404
M3 - Article
AN - SCOPUS:85112054374
VL - 197
JO - Applied thermal engineering
JF - Applied thermal engineering
SN - 1359-4311
M1 - 117404
ER -