scholarly journals Experimental Study on Evaporation Heat Transfer Characteristicsof R32 in A Plate Heat Exchanger

2021 ◽  
Author(s):  
Jaewan Yang ◽  
DongChan Lee ◽  
Yongchan Kim
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Exchanger ◽  
Plate Heat Exchanger ◽  
Plate Heat ◽  
Evaporation Heat ◽  
Evaporation Heat Transfer

Evaporation Heat Transfer and Pressure Drop of Refrigerant R-134a in a Plate Heat Exchanger

1999 ◽  
Vol 121 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Y.-Y. Yan ◽  
T.-F. Lin
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Plate Heat Exchanger ◽  
Vapor Quality ◽  
Plate Heat ◽  
Evaporation Heat ◽  
Evaporation Heat Transfer ◽  
R 134A

The evaporation heat transfer coefficient and pressure drop for refrigerant R-134a flowing in a plate heat exchanger were investigated experimentally in this study. Two vertical counterflow channels were formed in the exchanger by three plates of commercial geometry with a corrugated sine shape of a chevron angle of 60 deg. Upflow boiling of refrigerant R-134a in one channel receives heat from the hot downflow of water in the other channel. The effects of the mean vapor quality, mass flux, heat flux, and pressure of R-134a on the evaporation heat transfer and pressure drop were explored. The quality change of R-134a between the inlet and outlet of the refrigerant channel ranges from 0.09 to 0.18. Even at a very low Reynolds number, the present flow visualization of evaporation in a plate heat exchanger with the transparent outer plate showed that the flow in the plate heat exchanger remains turbulent. It is found that the evaporation heat transfer coefficient of R-134a in the plates is much higher than that in circular pipes and shows a very different variation with the vapor quality from that in circular pipes, particularly in the convective evaporation dominated regime at high vapor quality. Relatively intense evaporation on the corrugated surface was seen from the flow visualization. Moreover, the present data showed that both the evaporation heat transfer coefficient and pressure drop increase with the vapor quality. At a higher mass flux the pressure drop is higher for the entire range of the vapor quality but the evaporation heat transfer is clearly better only at the high quality. Raising the imposed wall heat flux was found to slightly improve the heat transfer, while at a higher refrigerant pressure, both the heat transfer and pressure drop are slightly lower. Based on the present data, empirical correlations for the evaporation heat transfer coefficient and friction factor were proposed.

scholarly journals Evaporation Heat Transfer and Pressure Drop of Refrigerant R134a in a Plate Heat Exchanger

1997 ◽  
Author(s):  
Yi-Yie Yan ◽  
Tsing-Fa Lin ◽  
Bing-Chwen Yang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Plate Heat Exchanger ◽  
Vapor Quality ◽  
Plate Heat ◽  
Evaporation Heat ◽  
Evaporation Heat Transfer

The characteristics of evaporation heat transfer and pressure drop for refrigerant R134a flowing in a plate heat exchanger were investigated experimentally in this study. Two vertical counter flow channels were formed in the exchanger by three plates of commercialized geometry with a corrugated sine shape of a chevron angle of 60°. Upflow boiling of refrigerant R134a in one channel receives heat from the hot downflow of water in the other channel. The effects of the heat flux, mass flux, quality and pressure of R134a on the evaporation heat transfer and pressure drop were explored. The preliminary measured data for the water to water single phase convection showed that the heat transfer coefficient in the plate heat exchanger is about 9 times of that in a circular pipe at the same Reynolds number. Even at a very low Reynolds number, the present flow visualization in a plate heat exchanger with the transparent outer plate showed that the flow in the plate heat exchanger remains turbulent. Data for the pressure drop were also examined in detail. It is found that the evaporation heat transfer coefficient of R134a in the plates is quite different from that in circular pipe, particularly in the convective evaporation dominated regime at high vapor quality. Relatively intense boiling on the corrugated surface was seen from the flow visualization. More specifically, the present data showed that both the evaporation heat transfer coefficient and pressure drop increase with the vapor quality. At a higher mass flux the pressure drop is higher for the entire range of the vapor quality but the heat transfer is only better at high quality. Raising the imposed wall heat flux was found to slightly improve the heat transfer. While at a higher system pressure the heat transfer and pressure drop are both slightly lower.

Evaporation Heat Transfer and Pressure Drop of Refrigerant R-410A Flow in a Vertical Plate Heat Exchanger

2003 ◽  
Vol 125 (5) ◽  
pp. 852-857 ◽  
Author(s):  
Y. Y. Hsieh ◽  
T. F. Lin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Exchanger ◽  
Vertical Plate ◽  
Plate Heat Exchanger ◽  
Vapor Quality ◽  
Plate Heat ◽  
Evaporation Heat ◽  
The Mean ◽  
Evaporation Heat Transfer

Experiments are carried out here to measure the evaporation heat transfer coefficient hr and associated frictional pressure drop ΔPf in a vertical plate heat exchanger for refrigerant R-410A. The heat exchanger consists of two vertical counterflow channels which are formed by three plates whose surface corrugations have a sine shape and a chevron angle of 60 deg. Upflow boiling of refrigerant R-410A receives heat from the hot downflow of water. In the experiments, the mean vapor quality in the refrigerant channel is varied from 0.10 to 0.80, the mass flux from 50 to 100 kg/m2s, and the imposed heat flux from 10 to 20 kW/m2 for the system pressure fixed at 1.08 and 1.25 MPa. The measured data indicate that both hr and ΔPr increase with the refrigerant mass flux except at low vapor quality. In addition, raising the imposed heat flux is found to significantly improve hr for the entire range of the mean vapor quality. However, the corresponding friction factor ftp is insensitive to the imposed heat flux and refrigerant pressure. Based on the present data, empirical correlations are provided for hr and ftp, for R-410A in the plate heat exchanger.

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