Research on flow and heat transfer characteristics of printed circuit plate heat exchangers in lubricating oil-water heat exchange

This study investigated the flow and heat transfer characteristics of the straight channel printed circuit heat exchanger (PCHE) in the heat exchange between lubricating oil (No. 68) and cooling water through numerical simulation, and compared and analyzed the effects of upstream and downstream arrangements and oil inlet flow velocity. The results indicate that the temperature of the lubricating oil varies approximately linearly along the axial direction (due to the significant gradient of the inlet effect in the inlet region); under both arrangements, the pressure drop increases linearly with the oil velocity; the increase in oil outlet temperature slows down with the increase of flow rate, and the outlet temperature is lower when arranged in reverse flow; the Nusselt number and convective heat transfer coefficient increase with increasing Reynolds number, while the Fanning friction factor continues to decrease with increasing flow velocity. Overall, it is shown that the PCHE with countercurrent arrangement has better heat transfer efficiency within the flow velocity range of 1-6 m/s, providing a theoretical basis for the optimization design of the oil-water heat exchange system.