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TWO-PHASE FRICTIONAL PRESSURE DROP AND FLOW BOILING HEAT TRANSFER FOR R245fa IN A 1.1 MM TUBE

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Author(s):
Da Silva, J. D. ; Tibirica, C. B. ; Ribatski, G. ; INT INST REFRIGERAT
Total Authors: 4
Document type: Journal article
Source: 23RD IIR INTERNATIONAL CONGRESS OF REFRIGERATION; v. 23, p. 3-pg., 2011-01-01.
Abstract

Experimental two-phase frictional pressure drop and flow boiling heat transfer results are presented for a horizontal 1.1 mm 1.D stainless steel tube using R245fa as working fluid. The frictional pressure drop data was obtained under adiabatic conditions. Experiments were performed for mass velocities ranging from 100 to 700 kg/m(2)s, heat flux from 0 to 95 kW/m(2), exit saturation temperatures of 31 and 41 degrees C, and vapor qualities up to 0.97. Pressures drop gradients and heat transfer coefficients ranging from 30 to 170 kPa/m and from 1 to 8 kW/m(2)K were measured. It was found that the heat transfer coefficient is a strong function of the heat flux, mass velocity and vapor quality. Five frictional pressure drop predictive methods were compared against the experimental database. Lockhart and Martinelli (1949) method predicted the adiabatic flow boiling experimental data with a mean absolute error around 12%. Four flow boiling heat transfer predictive methods were also compared against the present database and Saitoh et al. (2007) method predicted the experimental flow boiling heat transfer data with a mean absolute error around 20%. (AU)

FAPESP's process: 07/53950-5 - A theoretical and experimental study on flow boiling heat transfer and critical heat flux in microchannels
Grantee:Cristiano Bigonha Tibirica
Support Opportunities: Scholarships in Brazil - Doctorate