The invention relates to the technical field of refrigerating systems, and discloses a single-
machine double-
system type hot
fluorine defrosting refrigerating
system which comprises a main
machine refrigerating
system, an auxiliary
machine refrigerating system and two gas-liquid separators, the main machine refrigerating system comprises a first-stage compressor, a first-stage condenser, a first-stage expansion valve and a first-stage
evaporator, and the auxiliary machine refrigerating system comprises a second-stage compressor, a second-stage condenser, a second-stage expansion valve and a second-stage
evaporator; the auxiliary machine
refrigeration system comprises a second-stage compressor, a second-stage condenser, a second-stage expansion valve, a second-stage
evaporator, a third-stage condenser, a third-stage expansion valve and a third-stage evaporator. According to the technical scheme, the double
refrigeration circulation paths are introduced into the
refrigeration system, during refrigeration, the main machine refrigeration system is responsible for refrigeration, the auxiliary machine refrigeration system supplies liquid to the main machine refrigeration system for undercooling, the
heat load is relieved, and the unit refrigeration capacity is improved; in the
defrosting process, the auxiliary machine refrigeration system is adopted for generating high-temperature and high-pressure hot
fluorine for
defrosting, the
energy consumption of hot defrosting is reduced, fire hazards caused by aging of
electric heating elements are avoided, and the
safety coefficient of system operation is improved.