Heat transfer mechanism of horizontal shell-and-tube latent thermal energy storage units

Taking the horizontal shell-and-tube latent thermal energy storage unit as the research object, establishes a mathematical model of coupled flow and heat transfer considering phase change, and studies the heat transfer mechanism of the melting/solidification process of the unit. The results show that the heat transfer mechanism in the melting process is from heat conduction to natural convection and then to heat conduction again, while in the solidification process, the heat transfer mechanism is dominated by heat conduction throughout the whole process. Natural convection has a great influence on the melting process, can strengthen heat transfer and reduce the total melting time, but has little influence on the solidification process. Due to the enhanced heat transfer effect of natural convection, the heat storage rate in the melting process will experience a process from rapid declining to rising and then to slowly falling until the end of the melting process. The heat release rate in the solidification process first rapidly decreases and then slowly decreases until the end of the solidification process. The absorption and release of heat during melting and solidification processes are dominated by latent heat.