中文摘要：

本文对PAG、POE、PAO和AB四种润滑油特性进行了分析，结果表明PAG具有较好的综合性能。又从PAG／CO2混合物的溶解性和粘温特性证明了PAG比较适合CO2跨临界循环。最后对工质CO2夹带的微量PAG对压缩机、膨胀机、气体冷却器和蒸发器的性能影响分别进行了分析，并提出了超临界换热分析模型。结果表明润滑油虽然有助于改善压缩机、膨胀机性能，但造成了换热器性能的严重下降。

英文摘要：

The characteristic of synthetic lubricant PAG, POE, PAO and AB had been analyzed, and was verified that PAG with better over-all properties. Both solubility and viscosity-temperature properties of PAG/CO2 mixtures also showed that PAG suited system of carbon dioxide transcritical cycle. The effects of little of lubricant in CO2 on the performance of compressor, expander gas-cooler and evaporator were analyzed, and the model of supercritical heat transfer was also proposed. It found that PAG is favorable to improve performances of compressor and expander, but reduce heavily performance of heat exchanger.