Please use this identifier to cite or link to this item: https://scholarbank.nus.edu.sg/handle/10635/182942
Title: FREON-WATER HEAT TRANSFER IN PLATE HEAT EXCHANGERS
Authors: BELINDA YAP SWEE LI
Issue Date: 1999
Citation: BELINDA YAP SWEE LI (1999). FREON-WATER HEAT TRANSFER IN PLATE HEAT EXCHANGERS. ScholarBank@NUS Repository.
Abstract: An experimental study on single and two phase heat transfer and friction characteristics for R-123 inside a plate heat exchanger (PRE) was conducted. Single phase heat transfer and friction factor correlations were obtained for upflow and downflow conditions. There is no apparent distinction in heat transfer coefficient between the two configurations as seen from the heat transfer correlations derived for the PHE under study: for upflow, Nu = 0.111 Re 0.8026 Pr 0.333 and for downflow, Nu = 0.0938 Re 0.8374 Pr 0.333 However, the friction factor during single phase downflow in a PHE is considerably higher than that for upflow due to effects of gravitational acceleration. The single phase friction factor correlations derived for the PHE under study are: for upflow, f = 8.049 Re -0.1038 and for downflow, f = 771.43 Re -0.6371 In evaporation and condensation processes, the heat transfer coefficient correlations have been established in a wide range of operating conditions of mass flux, vapor quality, heat flux and saturation pressure. The evaporation process was found to b substantially more efficient than condensation. The heat transfer coefficient fo evaporation was correlated using the dimensionless parameters of Ruquid, Martinell parameter and Boiling number. The correlation derived is: Ruquid = 0.0034 Xtt.Bo -0.8492 In condensation, the dimensionless parameters applied are Rliquid and Martinelli parameter only and the correlation derived is: R liquid = O.9704 Xtt.-0.5224 The results obtained from this study show that the performance of the PHE with the new refrigerant, R123, can be ascertained with correlations used to predict its performance with other existing fluids. This is very encouraging in view of the increasing demand for new environmental-friendly refrigerants which will replace the older ones, soon to be phased out.
URI: https://scholarbank.nus.edu.sg/handle/10635/182942
Appears in Collections:Master's Theses (Restricted)

Show full item record
Files in This Item:
File Description SizeFormatAccess SettingsVersion 
b21439369.pdf4.43 MBAdobe PDF

RESTRICTED

NoneLog In

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.