Relationship between chevron angle and heat transfer performance of plate heat exchangers

The chevron angle (beta) of a plate heat exchanger significantly affects its heat transfer performance. This study aims to quantify the relation between heat transfer performance and chevron angle. Large eddy simulations of fully developed flow and heat transfer within the heat exchanger channels were conducted to determine heat transfer coefficients, covering a wide range of Reynolds numbers (10 <= Re <= 6000) and chevron angles (18 degrees <=beta <= 72 degrees). Correlations between the Nusselt number, pressure drop, Reynolds number, and friction factor were established, providing two approaches to predict the heat transfer coefficient across laminar and turbulent flow regimes. The results show that at low Reynolds numbers, increasing beta markedly enhances heat transfer, while at high Reynolds numbers, the enhancement is more moderate. Additionally, high- resolution maps of the local heat transfer coefficient on the corrugated surface offer deeper insights into the heat transfer characteristics within the exchanger. The study also examines the validity of the heat-mass transfer analogy, revealing significant discrepancies between heat and mass transfer coefficients, suggesting they should not be used interchangeably.