A loop thermoacoustic refrigeration system using flexible resonance tubes. Part I: Inner diameter variation and simulation analysis

In order to promote the engineering application of heat-driven thermoacoustic refrigeration technology, this paper proposes a loop thermoacoustic refrigeration system using flexible resonance tubes. While reducing the difficulty of design and assembly, it can be applied to different installation scenarios. A flexible tube radial deformation testing platform was built to explore the influence of working pressure changes on the inner diameter variations of flexible resonance tube. The effects of inner diameter, length, and position of flexible resonance tube on the system performance were theoretically analyzed. The two-stage loop thermoacoustic system using flexible resonance tubes was optimized and compared with traditional thermoacoustic system. The results show that the inner diameter of a flexible tube with an initial inner diameter of 25 mm increases by 11.47% at 8 MPa, and the higher the working pressure, the slower the inner diameter of flexible tube varies. The two-stage loop acoustic field is more sensitive to the inner diameter variations of resonance tube near the low-temperature end of refrigerator. Flexible tube cannot be used for its entire length, while the other resonance tube can use flexible tube for the entire length. The optimized two-stage loop thermoacoustic system ultimately achieved a relative Carnot total efficiency of 14.17% and a cooling capacity of 5.19 kW. Its performance exceeded that of the thermoacoustic system using stainless steel resonance tubes, and has the potential for engineering applications.