Overview and analysis of the properties of environmentally friendly freons — working fluids in an air source heat pump

Abstract

The growing popularity of the use of heat generators based on renewable sources - air source heat pumps is accompanied by an increase in the urgency of the issue of their modernization in order to increase efficiency. In this case, an important role is played by the working medium of the internal circuit of the heat pump - the refrigerant (freon). The Montreal Protocol imposes restrictions on the choice of freon, according to which the use of substances that destroy the ozone layer is prohibited. When choosing a refrigerant, it is necessary to take into account all the qualities and factors that characterize the possibilities in their working conditions. Based on information from domestic and international regulatory documents, it is possible to form groups of requirements for choosing a refrigerant for an air source heat pump, which are optimal according to various criteria. In particular, with regard to harmlessness to humans, a group of requirements for freons can also be distinguished: the practical limit of the refrigerant concentration and the maximum permissible concentration. Today, it is extremely important to evaluate and take into account the indicators of environmental safety of refrigerants. This article provides an assessment of the environmental safety indicators of a selected group of freons, selected according to the criterion of frequency of use. Assessing the indicators of environmental safety of the analyzed refrigerants, the selected priority indicators were compiled into one generalizing (integral) indicator, by the value of which it becomes possible to judge the environmental safety of refrigerants. For this, we consider the largest and best values. The results of the study are presented in the form of an infographic model.