Performance analysis of a vapor injection linear compressor in a dual-temperature zone refrigerator

Abstract

The vapor injection linear compressor exhibits a distinctive mass flowrate distribution characteristic compared to other vapor injection compressors, making it promising for application in dual-temperature zones refrigerating systems. In this study, a novel system of dual-temperature zone refrigerators featuring two parallel evaporators is proposed, and numerical models of the vapor injection linear compressor and its system are established, and then validated by experimental results. Theoretical analysis is conducted to explore the cooling performance and capacity-modulating characteristics of the system. Compared to traditional refrigeration systems, the vapor injection of medium-pressure refrigerant enhances the cooling capacity and performance at a large piston stroke while deteriorating the freezing capacity at a small piston stroke. This system offers the flexibility of adjusting the cooling ratio by modulating supply voltage and driving frequency to meet the cooling requirements. Correspondingly, special control strategies for this kind of system for the best performance are proposed in this study. Additionally, the structural parameters significantly influence the cooling performance: a larger injection area and a smaller distance to the top death center prove to be more advantageous for overall cooling performance. This research provides valuable insights for optimizing the structural parameters and control strategies, serving as a beneficial reference for future innovative refrigeration technologies.