Experimental analysis of condensation heat transfer and frictional pressure drop in a horizontal circular mini channel

Abstract

The present study aims to investigate the effect of working fluid, mass flux, vapour quality and saturation temperature on local condensation Heat Transfer Coefficient (HTC) and local Frictional Pressure Drop (FPD) in a horizontal circular mini-channel. The refrigerants HFO-1234yf and HFC-R134a have been used as a working fluids. The mass flux was varied from 200 to 800 kg/m2 s whereas two distinct saturation temperatures were used: 35 °C and 40 °C. The experimental analysis was carried out using horizontal circular single port mini-channel of hydraulic diameter 1 mm. During experiment, inlet condition of refrigerant was maintained to be saturated vapour. The results show that HTC and FPD increases with increase in vapour quality and mass flux whereas decreases with increase in saturation temperature. The experiment results of present study and previously published results are compared with various predictive models. Models which show minimum deviation from experimental results were used to develop new modified model to predict HTC with MARD of ± 15 % and FPD with MARD of ± 10 %.