涡旋膨胀机研究进展及展望

With the proposal of the "carbon peaking and carbon neutrality" target, the scroll expander has garnered attention as a mechanical device for the recovery of low-grade energy. An overview of the theoretical research achievements of scroll expanders in recent years are provided, mainly including profile theory, thermodynamics, and computational fluid dynamics (CFD) simulation. Subsequently, the application of scroll expanders in organic Rankine cycles (ORC) is summarized. The application research results of scroll expanders in transcritical CO₂ refrigeration cycles are collated. Lastly, the future research directions for scroll expanders are projected. The findings indicate that the variable wall thickness scroll expander, which can increase the volumetric ratio without lengthening the leakage path, will become the main direction for future profile optimization; CFD simulation has emerged as a significant research tool; lubricant is a key factor affecting the performance of scroll expanders, where increasing the viscosity of the lubricant can enhance efficiency, while an excess of lubricant will reduce the performance, working pressure is the most critical factor affecting the performance of scroll expanders, with phenomena such as over-expansion, under-expansion, and leakage leading to decreased performance. Moreover, the integrated scroll compression-expansion unit, which combines the expander and compressor into one casing, significantly simplifies the system structure and improves energy recovery efficiency, proving to be an effective way to enhance the performance of CO₂ heat pump air-conditioning systems for new energy vehicles. Based on current research achievements and industry demands, future development of scroll expanders should continue to delve into and optimize profile design? reduce leakage, and optimize working pressure, to meet the growing needs for energy recovery and environmental protection.