Investigation of Geometrical Parameters on Heat Transfer Performance in Pillow Plate Heat Exchangers Across Varied Reynolds Numbers

Abstract

This numerical simulation study investigates a pillow plate heat exchanger, exploring the influence of changes in pillow channel height, longitudinal, and transverse distances of welding points on Nusselt number, friction factor, and thermal performance across a range of Reynolds numbers from 1000 to 7000. The fluid inlet temperature is held constant at 298 K, with a heat flux of 5000 W/m² applied to both upper and lower plates in all simulations, providing a consistent basis for comparison. Firstly, the analysis delves into the effects of varying pillow channel height on heat transfer efficiency and fluid flow dynamics within the heat exchanger. Transitioning from a Reynolds number of 1000 to 7000, the friction factor is decreased by 43.2%, 45.7%, and 41.9% for channel heights of 3 mm, 5 mm, and 7 mm, respectively. Secondly, the study examines the impact of different longitudinal distances of welding points on key performance indicators such as Nusselt number, friction factor, and thermal performance. According to the acquired data, the Nusselt numbers for the highest Reynolds number are 175.439, 163.3, and 154.579 for models with longitudinal distances of the welding points ranging from 50 to 70 mm, respectively. Lastly, the research investigates how alterations in the transverse distances of welding points affect Nusselt number, friction factor, and overall thermal performance of the heat exchanger.