부산대학교 도서관

Documents such as the Lisbon Protocol and the EU Green Pact call for the development of environmentally friendly processes and technologies to drastically reduce greenhouse gas emissions (carbon dioxide, freons, etc.) and limit the devastating consequences of climate change. Today, most industrial refrigeration, air conditioning and personal comfort processes are carried out using equipment that uses freons (chlorofluorocarbons) as the working medium. However, the widespread use of all types of freon is questioned because of the destruction of the ozone layer in the stratosphere and the accumulation of large amounts of ultraviolet radiation on Earth, as well as the trapping of upward thermal radiation in the Earth's atmosphere, which causes the well-known greenhouse effect. This paper presents cooling and airconditioning processes that produce artificial cold by using air as a working medium, an inexhaustible ecological resource that exists everywhere in space and time. Using compressed air as the working medium, three types of thermodynamic processes are presented theoretically and experimentally: free flow in the tube, free expansion in a centrifugal field as a proprietary solution, and expansion in a centrifugal field and energy separation/Ranque-Hilsch effect. The paper concludes by summarising the findings and making recommendations for further research. [ABSTRACT FROM AUTHOR]