Numerical simulation of heat transfer processes in shell and tube phase change heat exchangers for recovering industrial waste heat

Abstract This article combines phase change energy storage technology with shell and tube heat storage and exchange devices to establish a three-dimensional numerical model of the shell and tube phase change heat storage and exchange device. The hexahedral structured grid division is used to make the simulation results more accurate. Combined with the computational fluid dynamics software Fluent and the related principles of phase change heat transfer, the effects of different heat transfer fluid temperatures and flow rates on the phase change process of phase change materials and the fluid outlet temperature in the phase change heat exchanger were numerically simulated. The results show that under the set parameters, when the inlet water temperature increases from 70 °C to 90 °C, the time required for the outlet temperature to increase from 20 °C to 60 °C is shortened by 23%, while when the temperature is constant, the inlet temperature of heat transfer fluid is shortened by 69%. Analysis shows that the influence of the inlet temperature of the heat transfer fluid on the heat storage and release of phase change materials is significantly greater than the inlet flow rate.