Abstract: To provide a defrost system capable of preferable defrosting and prevention of generation of icicles on a casing without installing a brine circuit. A defrost system includes a thermosiphon defrost circuit that is provided by being branched from a circulation line, in which, at the time of defrosting, a CO2 refrigerant staying inside a fin-tube heat exchanger repeats a two-phase change of a gaseous form and reliquefaction, and which forms a CO2 circulation path together with the fin-tube heat exchanger; electromagnetic opening/closing valves that are closed at the time of defrosting and set the CO2 circulation path to a closed circuit; and a first electric heater arranged above the thermosiphon defrost circuit so as to be adjacent to the thermosiphon defrost circuit, and naturally circulates the CO2 refrigerant in the closed circuit at the time of defrosting.

Abstract: To provide a defrost system capable of preferable defrosting and prevention of generation of icicles on a casing without installing a brine circuit. A defrost system includes a thermosiphon defrost circuit that is provided by being branched from a circulation line, in which, at the time of defrosting, a CO2 refrigerant staying inside a fin-tube heat exchanger repeats a two-phase change of a gaseous form and reliquefaction, and which forms a CO2 circulation path together with the fin-tube heat exchanger; electromagnetic opening/closing valves and that are closed at the time of defrosting and set the CO2 circulation path to a closed circuit; and a first electric heater arranged above the thermosiphon defrost circuit so as to be adjacent to the thermosiphon defrost circuit, and naturally circulates the CO2 refrigerant in the closed circuit at the time of defrosting.

Abstract: A defrost system is disclosed that includes a cooling device disposed in a freezer, a heat exchanger pipe leading into a casing, a drain receiver unit; a refrigerating device for cooling and liquefying CO2 refrigerant; a refrigerant circuit for permitting the CO2 refrigerant to circulate to the heat exchanger pipe; a defrost circuit branched from the heat exchanger pipe forming a CO2 circulation path with the heat exchanger pipe; an on-off valve so that the CO2 circulation path becomes a closed circuit; a pressure adjusting unit for adjusting the pressure of the CO2 refrigerant; and a first heat exchanger unit for heating the CO2 refrigerant circulating with brine, disposed below the cooling device to which the defrost circuit and a first brine circuit in which brine, a first heating medium, circulates, are led, in which the CO2 refrigerant naturally circulates in the closed circuit when defrosting by a thermosiphon effect.

Abstract: A defrost system includes: a cooling device in a freezer, and includes a casing, a heat exchanger pipe with a difference in elevation in the casing, and a drain receiver unit below the heat exchanger pipe; a refrigerating device to cool and liquefy CO2 refrigerant; and a refrigerant circuit for permitting the cooled and liquefied CO2 refrigerant to circulate to the heat exchanger pipe. The defrost system includes a bypass pipe of the heat exchanger pipe to form a CO2 circulation path; an on-off valve in the heat exchanger pipe to be closed during defrosting so that the CO2 circulation path is a closed circuit; a pressure adjusting unit for adjusting pressure of the CO2 refrigerant during defrosting; and a brine circuit as a first heating medium, in which the defrost system permits the CO2 refrigerant to naturally circulate in the closed circuit during defrosting by a thermosiphon effect.

Abstract: A defrost system includes: a cooling device in a freezer, and includes a casing, a heat exchanger pipe with a difference in elevation in the casing, and a drain receiver unit below the heat exchanger pipe; a refrigerating device to cool and liquefy CO2 refrigerant; and a refrigerant circuit for permitting the cooled and liquefied CO2 refrigerant to circulate to the heat exchanger pipe. The defrost system includes a bypass pipe of the heat exchanger pipe to form a CO2 circulation path; an on-off valve in the heat exchanger pipe to be closed during defrosting so that the CO2 circulation path is a closed circuit; a pressure adjusting unit for adjusting pressure of the CO2 refrigerant during defrosting; and a brine circuit as a first heating medium, in which the defrost system permits the CO2 refrigerant to naturally circulate in the closed circuit during defrosting by a thermosiphon effect.

Abstract: A defrost system is disclosed that includes a cooling device disposed in a freezer, a heat exchanger pipe leading into a casing, a drain receiver unit; a refrigerating device for cooling and liquefying CO2 refrigerant; a refrigerant circuit for permitting the CO2 refrigerant to circulate to the heat exchanger pipe; a defrost circuit branched from the heat exchanger pipe forming a CO2 circulation path with the heat exchanger pipe; an on-off valve so that the CO2 circulation path becomes a closed circuit; a pressure adjusting unit for adjusting the pressure of the CO2 refrigerant; and a first heat exchanger unit for heating the CO2 refrigerant circulating with brine, disposed below the cooling device to which the defrost circuit and a first brine circuit in which brine, a first heating medium, circulates, are led, in which the CO2 refrigerant naturally circulates in the closed circuit when defrosting by a thermosiphon effect.