This paper provides a theoretical assessment of the thermal performance of a new CO₂ vapour-compression system for refrigerated transport applications. Three different configurations are investigated: the standard back-pressure with low pressure receiver lay-out and two arrangements integrating a two-phase ejector. In particular, the use of an auxiliary evaporator in the outlet line of the ejector is considered, to extend the ejector operating range. A numerical model of the system is developed and its theoretical performance is discussed for different values of internal space temperature and external ambient temperature. Simulations’ results show that the ejector cycle configuration is convenient when the system is operating in a hot climate with a maximum COP increase (compared to the traditional configuration) equal to 15.9%, at 42°C ambient temperature and -5°C internal space temperature. The use of an auxiliary evaporator can extend the operating range of the ejector to lower values of ambient temperature, with a maximum COP improvement (over the traditional configuration) equal to 21.0% at 25°C ambient temperature and 5°C internal cargo space.

本文对新型CO ₂的热性能进行了理论评估用于冷藏运输应用的蒸汽压缩系统。研究了三种不同的配置：具有低压接收器布局的标准背压以及集成了两相喷射器的两种配置。特别地，考虑在喷射器的出口管线中使用辅助蒸发器，以扩大喷射器的工作范围。建立了该系统的数值模型，并针对内部空间温度和外部环境温度的不同值讨论了其理论性能。仿真结果表明，当系统在炎热气候下运行时，喷射器循环配置很方便，COP最大值增加（与传统配置相比）为1​​5.9％，为42°C环境温度和-5内部空间温度。使用辅助蒸发器可以将喷射器的工作范围扩展到较低的环境温度值，在25°C时，最大COP改进（相对于传统配置）为21.0％°C环境温度和5°C内部货物处所。