A numerical study of elastocaloric regenerators of tubular structures

Abstract

Solid-state elastocaloric cooling is increasingly recognized as preferred cooling technology to conventional vapor compressions without using coolants that are volatile atmospheric pollutants or greenhouse gases with global warming potential. However, the specific cooling power (SCP) of current prototypes has yet to be improved in meeting practical requirements. In this work, tubular nickel-titanium (NiTi) elastocaloric regenerators with enhanced heat transfer structures were proposed in order to increase cooling performance in compression-loaded regenerative systems. A numerical model was developed to evaluate this cooling performance. Using a nondimensional analysis of the governing equations, the model simplifies the investigation of the design and operation parameters and greatly reduces the computation complexity of the regenerative elastocaloric cooling systems. As a demonstration, the design principles have been applied to yield an elastocaloric regenerator of spiral-shaped tubular structures, which improves the maximum SCP and maximum temperature span by 186% and 146% respectively, compared to a plain tube design, proving that the numerical model provides a promising pathway for developing energy-efficient elastocaloric cooling systems.