Development of Automobile Air Conditioning System Using CO_2 as Working Fluid

摘要

To help prevent global warming, the refrigerant HFC134a currently used in automobile air-conditioners has been slated for eventual elimination. CO_2, a natural refrigerant, has attracted attention as an alternative. We developed high-pressure control to improve evaporator, gas-cooler, intercooler, and compressor efficiency and to maximize COP (Coefficient Of Performance) in automobile air-conditioning using a supercritical refrigeration cycle with CO_2 as the refrigerant. An evaluation of the system verified that these improved components provide equal or better COP than systems using HFC134a.