Heat transfer during condensation of refrigerants in tubular minichannels

Condensation Heat Transfer of Pure Refrigerants in Microfin Tubes

Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate Heat Exchanger

Average Nusselt numbers were measured for R22, R290, R290/600a, and R32/152a undergoing evaporation and condensation in a brazed plate heat exchanger. The refrigerants experienced wavy, stratified flow at low heat and mass fluxes, 1.3 kW/m2 to 8.3 kW/m2 and 1.6 kg/m2 s to 19 kg/m 2 s, respectively. Heat transfer correlations from the literature for in-tube and channel flow of refrigerants with ...

Condensation Heat Transfer of New Refrigerants: Advantages of High Pressure Fluids

Heat transfer condensation tests inside a 8 mm ID tube for R-134a, R-410A and R-125 are reported at an average saturation temperature of 40°C, at mass velocities ranging from 65 to 750 kg/(m s), over the entire vapour quality range. After comparing the experimental data against a model able to predict both shear force and gravity driven condensation, a comparison among these fluids has been car...

Boiling local heat transfer enhancement in minichannels using nanofluids

This paper reports an experimental study on nanofluid convective boiling heat transfer in parallel rectangular minichannels of 800 μm hydraulic diameter. Experiments are conducted with pure water and silver nanoparticles suspended in water base fluid. Two small volume fractions of silver nanoparticles suspended in water are tested: 0.000237% and 0.000475%. The experimental results show that the...

simulation of the convection heat transfer in tubular heat exchanger

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