Numerical simulation of a foam regenerator for elastocaloric cooling

Abstract

The severe consequences of global warming lead to increased demand for environment-friendly cooling technologies. Elastocaloric cooling technology is one of the most promising alternatives to vapor-compression refrigeration technology because of its high energy efficiency and zero global warming potential (GWP). However, the commercialization of this technology is still hindered by its limited specific cooling power (SCP). To overcome this obstacle, this paper proposes a new regenerator design using shape-memory alloy (SMA) foams. A numerical simulation model was used to demonstrate that the SCP of the system with foam regenerators is 3.55 and 0.71 times greater than that of the baseline system with parallel-plate regenerators and tube regenerators. The performance of the system with a pair of foam regenerators is investigated in terms of operating frequency, fluid velocity, and geometric parameters. The theoretical SCP of the elastocaloric cooling system with foam regenerators is up to 80Wg-1, which far exceeds experimental and simulation results found in previous literature. Considering the compromise between cooling performance and power consumption, structural parameters with a porosity of 0.9 and a cell diameter of 2 mm and operating parameters with a fluid velocity of 2.2ms-1 and a frequency of 5 Hz are recommended.