Condensation Heat Transfer of Mixed Refrigerants inside a Horizontal Tube.

An Experimental Investigation of Convective Boiling Heat Transfer Using Alternative and Natural Refrigerants Inside Horizontal Microchannels

In present study, the two phase flow boiling heat transfer coefficient and pressure drop of R410A, R32 and R290 in microchannels are demonstrated. The experimental data were conducted in horizontal stainless steel tubes with the inner diameter of 0.3 mm and 1.5 mm. The testing conditions were performed with the mass fluxes range from 200 to 500 kg/m2s, the heat fluxes from 10 to 20 kW/m2, the s...

Experimental and Theoretical Study on Condensation Heat Transfer of Nonazeotropic Refrigerant Mixtures R1234yf/R32 Inside a Horizontal Smooth Tube

The condensation heat transfer characteristics of nonazeotropic mixtures R1234yf and R32 (mass fractions of 0.52:0.48 and 0.77:0.23, respectively) inside a horizontal smooth tube (inner diameter 4 mm) were experimentally studied at mass fluxes ranging from 100 to 300 kg/m s. A prediction model for the forced convective condensation heat transfer characteristics of nonazeotropic refrigerant mixt...

Condensation Heat Transfer of Pure Refrigerants in Microfin Tubes

Condensation Heat Transfer Coefficients of HFC245fa on a Horizontal Plain Tube

In this study, condensation heat transfer coefficients (HTCs) of HCFC22, HCFC123, HFC134a and HFC245fa are measured on a horizontal plain tube 19.0 mm outside diameter. All data are taken at the vapor temperature of 39 with a wall subcooling temperature 3-8 . Test results show the HTCs of newly developed alternative low vapor pressure refrigerant, HFC245fa, on a smooth tube are 9.5% higher than...

Convective Heat Transfer of Oil Based Nanofluid Flow Inside a Circular Tube

Abstract   An empirical investigation was carried out to study convective heat transfer of nanofluid flow inside an inclined copper tube under uniform heat flux condition. Required data are acquired for laminar and hydrodynamically fully developed flow inside round tube. The stable CuO-base oil nanofluid with different nanoparticle weight fractions of 0.5%, 1% and 2% was produced by means of ul...