Selection of optimal fluid for refrigeration cycles

Refrigeration and air-conditioning play an important role in our life and industrial applications. They have great impact on our life. They have also contributed to the world’s major environmental issues like ozone layer depletion and global warming. Common refrigerants such as CFCs and HCFCs which are working as fluid in refrigeration cycles have unfavorable environmental impacts and this has brought about concerns and regulations prohibiting their production and use as refrigerants by the year 2030. The development of different refrigerants over time took place based on safety and environmental impact issues. This paper, presents the selection of optimal working fluids for Vapor-Compression Refrigeration Cycle (VCRs) based on computer aided molecular design (CAMD) and process optimization techniques. The resulting methodology utilizes from CAMD for the generation of optimum working fluid candidates. Candidates were evaluated as alternative refrigerants for the R134a refrigerating system through simulation using Aspen Hysys V8.0, with restricted by priority coefficient of performance COP, environmental and safety criteria. Ethyl trifluoromethyl ether 1,1,1-TrifluoroButane (new refrigerant) shows a good environmental and toxicity data also have high COP, 4.5, 2.7 respectively and were favored amongst the studied refrigerants as the choice alternative refrigerants to replace R134a. The methodology systematically identified conventional molecular structures that enable optimum VCRs process performance.