| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: composition contains: 7.0-9.0 wt % difluoromethane; 39.0-50.0 wt % pentafluoroethane; 39.0-50.0 wt % 1,1,1,2-tetrafluoroethane; 1.9-2.5 wt % hydrocarbon consisting of 1.5-1.8 wt % n-butane and 0.4-0.7 wt % isopentane or 0.4-0.7 wt % n-pantane, and perfluoropolyether. The invention also relates to a heat-transfer system, a cooling system or an air conditioning system, all elements of which are linked with each other by a fluid medium and contain a heat-transfer composition which contains: 7.0-9.0 wt % difluoromethane; 39.0-50.0 wt % pentafluoroethane; 39.0-50.0 wt % 1,1,1,2-tetrafluoroethane; 1.9-2.5 wt % said hydrocarbon. The invention also relates to a method of modifying a heat-exchange system containing chlorodifluoromethane. The method involves removing chlorodifluoromethane from the condenser-evaporator loop of the system and filling the condenser-evaporator loop of the system with a multi-component heat-transfer composition. The described compositions have usable potential from the view point of global warming, have low toxicity and have good cooling capacity. ^ EFFECT: compositions can serve as chlorodifluoromethane coolant substitutes with minimal changes to equipment. ^ 62 cl, 11 dwg, 5 tbl, 12 ex |
