Investigation Of Heat Transfer Performance Of Phase Change Thermal/Cold Storage Heat Exchanger

Latent thermal energy storage(LTES) is a special heat exchanger, which can solve the mismatch between energy supply and demand effectively. Numerous studies show that the LTES have low heat transfer rate and uneven temperature distribution. So the focus of the current study is to strengthen the heat transfer of LTES. In this paper, the heat transfer characteristics of three kinds of LTES are analyzed and optimized. The main contents and conclusions are as follows:Firstly, two kinds of optimal models are proposed in order to solve problems that the low rate of solidification/melting process and uneven temperature field distribution within the general shell-and-tube LTES. The results show that: In the exothermic process, the average heat transfer rates of model II and III are about 1.87 and 1.79 times of model I(original model); In the regenerative process, the average heat transfer rates of model II and III are about 1.87 and 1.92 times of model I(original model).Secondly, according to the character of triple-sleeve LTES exchangers, T-shaped fins are proposed to strengthen the heat transfer, and the impacts of fins and natural convection on the solidification/melting process are studied by numerical simulation. The results show that: the mixing structure of straight fin and T-shaped fin can save 74% time in solidification process and 61% of the time used in melting process than that of not reinforced; The impacts of natural convection to heat transfer in melting process is bigger than that of in solidification process.Finally, in order to improve the cabinet temperature distribution, optimal methods are proposed. Computational results that: adding fins can improve the cool storage efficiency and uniformity of temperature distribution of the cool storage shelf. Shorting the distance between heat pipes among the cool storage shelf can be further optimized the heat transfer.