Experimental study on condensation of heat pump plate-fin heat exchangers for new energy vehicles

This study experimentally investigates the condensation heat transfer performance of R134a in four plate-fin heat exchangers designed for electric vehicle battery thermal management, with particular attention to the effects of fin pitch, fin type ( Z -shaped versus H-shaped), saturation pressure, and coolant flow rate. The results reveal that at a saturation pressure of 1.318 MPa, the Z -shaped fin configuration achieves a condensation heat transfer coefficient approximately 9% higher than that of the H-shaped configuration, while at 1.492 MPa the H-shaped fin heat exchanger exhibits an average pressure drop roughly 130% greater than its Z -shaped counterpart. The heat transfer coefficient is found to increase with higher refrigerant mass flow rates and larger fin pitches, yet decreases as saturation pressure rises. Pressure drop increases with mass flow rate and is consistently greater for H-shaped fins, whereas it declines with larger fin pitches and higher saturation pressures. Collectively, these findings provide quantitative guidance for the design of compact, energy-efficient heat exchangers in electric vehicle thermal management systems.