Evaporation heat transfer characteristics of R290 in a chevron type plate heat exchanger under various operating conditions

R290 has emerged as a promising alternative for R410A and R32 due to its excellent thermodynamic properties and low environmental impact. However, studies on the evaporation heat transfer characteristics of R290 in chevron-type plate heat exchangers (PHEs) remain limited. This study investigates the evaporation heat transfer performance of R290 in a chevron-type PHE under various operating conditions and compares the results with those of R410A and R32. Experiments are conducted by varying mass flux, heat flux, and saturation temperature, respectively. The average heat transfer coefficient of R290 was 4.54 kW·m⁻²·K⁻¹, which was 24.3% and 12.6% higher than that of R410A and R32, respectively, due to its larger specific volume. However, the average frictional pressure drop of R290 was 112% and 64.1% higher than that of R410A and R32, respectively, owing to the greater difference in saturated specific volumes. New correlations for the Nusselt number and friction factor of R290, R410A, and R32 in chevron-type PHEs are developed by incorporating the two-phase Reynolds number, Prandtl number, and thermophysical refrigerant properties, with deviations within ±15%. Despite its higher pressure drop, R290 remains a compelling alternative to R410A and R32 due to its superior heat transfer performance and reduced environmental impact.