Study of Turbulent Flow Characteristics in Plate Heat Exchangers with Diffuser Channels

Numerical simulation of the flow and heat transfer in a unit of a counter-flow heat exchanger is carried out using a three-parameter differential RANS turbulence model supplemented by a transfer equation for a turbulent heat flow. The adjacent channels of the unit are flat, continuous diffusers with a smooth surface. The physical properties and thickness of the wall between the channels are taken into account. The analysis of the influence of the opening angle of the diffusers on the local and integral characteristics of the flow of hot and cold fluids, as well as heat exchange, shows that the intensity of turbulence and shear stress increase with an increase in the angle of inclination of the heat-transfer wall of the diffuser channel.