مواد سرمازا و وضعيت مبردها در قرن بيست ويكم

Refrigerants and the Situation of Its Industry in 21St Century

Recent evidence indicates that much of the damage to the atmospheric ozone layer is the result of decomposition of chlorofluoro carbon (CFC) chemicals. An international agreements known as the Montreal Protocol took effect in 1989 and a new Clean Air Act was signed into law in 1990 to limit the production and regulate the use and disposal of chlorofluoro carbons. The cholorofluoro carbons that cause ozone-layer depletion have been designated as CFC-type materials. Other refrigerants that are chlorofluoro carbons but cause little or no ozone destruction are designated as hydrochlorofluoro carbon (HCFC) or hydrofluoro carbon (HFC) refrigerants. Several terms are used to specify the relative destructiveness of chlorofluorocarbon refrigerants to the ozone layer, and other effects on the environments. The ozone depletion potential (ODP) is the ozone-destroying power of a substance measured relative to Refrigerants 11 (CFC-11) (R-11). The global warming potential (GWP) is a relative measure of the ability of a substance to cause an increase in the temperature of the atmosphere by absorbing solar and earth radiation that is relative to the effect of Refrigerant 11. Scientists designed and make new systems and instruments with the optimum use of energy. They and chemical engineers should discover safe and without any peril with the respect of environment.