二氧化碳（CO2）通常与温室效应和环境破坏有关，可用于对抗臭氧消耗。CO2（R744）是现有氟碳基制冷剂的实际替代品。尽管R744的全球变暖潜能（GWP）为1，但它比大多数其他常用制冷剂的GWP低1000-3000倍。本文采用热力学第一定律，即性能系数（COP），从理论上比较了R744与其他天然制冷剂的性能。它显示了R744压缩机的优化压力图，并概述了压缩机性能对制冷系统COP的影响。单位:SICitation:ASHRAE Transactions，第115卷，pt。 2、路易斯维尔2009

Carbon Dioxide (CO2), which is generally associated with green house effect and damage to the environment, can be used in the fight against ozone depletion. CO2(R744) is a practical replacement to existing fluoro-carbon based refrigerants. Although R744 has a global warming potential (GWP) of 1, it is about 1000-3000 times lower than the GWP of most other commonly used refrigerants. This paper follows a theoretic approach to compare the performance of R744 with other natural refrigerants, employing the first law of thermodynamics, i.e., using coefficient of performance (COP). It shows the optimized pressure plots of a R744 compressor and sketches the effect of compressor performance on the COP of the refrigeration system.Units: SI