Library Subscription: Guest
Home Archives Thermal Letter Officers Future meetings Assembly for International Heat Transfer Conferences
International Heat Transfer Conference 15

ISSN: 2377-424X (online)
ISSN: 2377-4371 (flashdrive)

Flow Boiling Heat Transfer in Small Cross Section Area Tubes with R134a and R32

Francisco Ramirez-Rivera
Technical University of Cartagena. Thermal and Fluids Engineering

Francisco Vera-Garcia
Department of Thermal and Fluids Engineering, Technical University of Cartagena, Doctor Fleming s/n, 30202 Cartagena, Spain

Jose Ramon Garcia-Cascales
Department of Thermal and Fluids Engineering, Technical University of Cartagena, Doctor Fleming s/n, 30202 Cartagena, Spain

Fernando Illan-Gomez
Technical University of Cartagena. Thermal and Fluids Engineering

DOI: 10.1615/IHTC15.tpb.008958
pages 8315-8330


KEY WORDS: Two-phase/Multiphase flow, Boiling and evaporation, compact heat exchanger, mini-channels, R32, R134a

Abstract

In this study, the characteristics of local heat transfer coefficient (HTC) and pressure drop are experimentally investigated in a multiport aluminium tube at low vapour qualities. The tube consists in 18 parallel triangular channels and hydraulic diameter of 0.715 mm. Two refrigerants of medium (R134a) and high (R32) reduced pressure are used as working fluids. The experimental ranges studied include: mass velocity [275−1230] kg·m−2s−1, heat flux [0.98−9.30] kWm−2, saturation temperature [285.65, 280.65, 278.15] K and vapour quality [0−0.55]. The flow boiling results indicated that the local HTC is strongly influenced by heat flux, and it is slightly affected by saturation temperature. Experimental HTC data are compared with six well-known micro/mini-channel predicting models; the comparisons show that "three zone flow boiling model" proposed by Thome et al. estimates quite well the experimental local HTC data of R134a, but none of the evaluated models estimate the flow boiling data of R32 with reasonable accuracy.

Purchase $25.00 Check subscription Publication Ethics and Malpractice Recommend to my Librarian Bookmark this Page