Decoupling mechanical stress and heat transfer in a tubular compression chamber for barocaloric refrigeration

Barocaloric refrigeration is a promising solid-state cooling technology for carbon-neutral refrigeration, whose performance strongly depends on the structural design of the compression chamber. In this study, a tubular compression chamber is proposed to physically separate the barocaloric material from the heat-transfer fluid, enabling decoupled cold generation and heat extraction. Two pressurization modes, external and internal, are investigated through mechanical and fluid-solid heat transfer simulations. Under a pressure of 500 MPa, the external pressurization mode requires a smaller tube wall thickness (1.2 mm) than the internal mode (1.63 mm) to keep the maximum stress below the yield strength of H13 steel. For the same barocaloric material mass (10 g), the external mode also significantly improves heat extraction, reducing the cooling time to 290 K from 77.4 s to 29.3 s. These results demonstrate that external pressurization simultaneously enhances structural reliability and heat transfer performance, providing a practical design strategy for high-performance barocaloric refrigeration systems.