О возможности взрыва при применении экологически безопасных хладагентов в холодильном оборудовании

Abstract

Today, the most common domestic electric equipment is a household refrigerator. The use of flammable substances as refrigerants for refrigerators can lead to severe consequences. As the production of hydrofluorocarbon class refrigerants for refrigeration equipment was restricted by the Kigali amendment to the Montreal Protocol, refrigeration technologies have been transferred from using hydrofluorocarbon class refrigerants to natural refrigerants (propane, butane, isobutane). The replacement of hydrofluorocarbon class refrigerants with natural refrigerants is already noticeable since in many cases isobutane (R-600a) is used as a refrigerant for refrigeration equipment. Isobutane is a combustible substance with a wide explosion limit (1.8–9.5 % vol.); hence, it is classified as an A2 refrigerant class of hazard (combustible substances). As R-600a is classified as an A2 class of fire hazard, its use in refrigeration technologies is limited with the refrigerant mass; therefore, the use of R-600a for refrigeration equipment is considered safe. According to international and Russian data, however, some accidents involving the use of flammable refrigerants in refrigeration equipment were registered. In the US, two explosions of serviceable household refrigerators were registered; in the Russian Federation, one explosion of refrigeration equipment during repair jobs was registered. According to the parameters of refrigeration equipment explosion, R-600а was used as a refrigerant. This study provides a calculation of excess pressure of explosion in case of leakage of R-600a from a refrigerator in the volume of a living accommodation (kitchen) in order to estimate the fire safety of combustible refrigerants. Based on the results of calculations, it has been concluded that the existing norms of the use of combustible refrigerants are insufficient and cannot ensure fire-explosion and fire safety for a person and refrigeration equipment.