In the paper, the main results of thermodynamic analysis and optimization of the hybrid two–stage carbon dioxide (СО₂) transcritical mechanical compression–ejector cooling cycle are presented. The proposed hybrid cooling cycle contains a two–stage CO₂ transcritical mechanical compression refrigeration machine and an ejector cooling machine using refrigerants R245ca, R601b, and R1233zd(E). The operation of the ejector cooling cycle is ensured by using some part of the heat rejected from the compressed superheated CO₂ vapor of the mechanical compression refrigeration cycle. The cold obtained in the ejector cooling machine is used for subcooling the high–pressure CO₂ vapor after the gas cooler. In addition, the intermediate cooling of the CO₂ vapor after the low–pressure stage of the mechanical compression refrigeration cycle is realized by preheating and boiling the refrigerant of the ejector cooling cycle in the additional generator–precooler before entering the main generator–precooler. This paper presents a method for determination of the optimal design parameters and performance of the proposed hybrid cooling cycle. The results showed an increase in efficiency of the two–stage CO₂ transcritical mechanical compression refrigeration machine in the proposed cooling system of up to 32.7% compared to the conventional system at transcritical operating conditions with high an environmental temperature.

本文介绍了混合两级二氧化碳 (СО ₂ ) 跨临界机械压缩-喷射器冷却循环的热力学分析和优化的主要结果。提议的混合冷却循环包含一个两级 CO ₂跨临界机械压缩制冷机和一个使用制冷剂 R245ca、R601b 和 R1233zd(E) 的喷射器冷却机。通过使用从机械压缩制冷循环的压缩过热CO ₂蒸汽排出的部分热量来确保喷射器冷却循环的运行。在喷射冷却机中获得的冷量用于过冷高压 CO ₂气体冷却器后的蒸汽。此外，机械压缩制冷循环低压阶段后的CO ₂蒸汽的中间冷却是通过在进入主发生器-预冷器之前在附加发电机-预冷器中预热和沸腾喷射冷却循环的制冷剂来实现的。本文提出了一种确定所提出的混合冷却循环的最佳设计参数和性能的方法。结果表明，在高环境温度的跨临界操作条件下，与传统系统相比，所提出的冷却系统中两级 CO ₂跨临界机械压缩制冷机的效率提高了 32.7%。