A new environment-friendly refrigerant

CFCs and HCFCs, widely used in refrigeration and air-conditioning equipment, have been or will be phased out according to the revisions of the Montreal Protocol because they deplete the ozone layer. Many substitutes have been proposed, but no one has perfectly replaced the CFC and HCFC refrigerants. New generation alternatives are being investigated worldwide. According to the industrial and environmental requirements, many factors should be considered in the screening and evaluation of refrigerant alternatives. A new method is proposed using the soft algebra method-fuzzy multiple evaluation. The weights for different factors are determined mathematically and criteria values for all the objects are made dimensionless to quantitatively compare the different alternatives. A new long-term drop-in mixture alternative THR02 is developed and evaluated in a series of theoretical and experimental evaluations. THR02 is proved to be an environment-friendly, nontoxic, inflammable, drop-in alternative to CFC-12 and HFC-134a. The thermal performance of the compressors and refrigerators with THR02 as a drop-in is equal to or higher than with CFC-12 and HFC-134a. The compressor and refrigerator using THR02 perform reliably after long-period running.