Experimental study of R410A and its low GWP alternative R452B flow boiling in a multiport microchannel tube

This study investigated the flow boiling performance of the refrigerants R410A and its low Global Warming Potential (GWP) alternative R452B in a multiport microchannel tube. Heat transfer coefficient (HTC) and pressure gradient (dP/dz) for the two refrigerants were measured. The experiments covered a range of mass flux from 100 to 250 kg m⁻²s⁻¹, heat flux from 2 to 8 kW m⁻², and inlet temperatures from 0 to 20 °C. This study analyzed the effect of vapor quality, mass flux, heat flux, and saturation pressure on HTC and dP/dz. Additionally, the study also employed a Pearson correlation coefficient analysis to reveal the influence of these conditions on refrigerant performance. The Pearson method provided insights into the nonlinear relationships between the tested parameters and their impact on the heat transfer and flow characteristics. Experimental results were compared with predictive models to validate their applicability in practical scenarios. The comparison led to a recommendation of models. Kim and Mudawar and Bertsch et al. models for predicting the pressure gradient and heat transfer coefficient, respectively, were highlighted for their predictive accuracy.