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 CO.sub.2 refrigerant; and a refrigerant circuit for permitting the cooled and liquefied CO.sub.2 refrigerant to circulate to the heat exchanger pipe. The defrost system includes a bypass pipe of the heat exchanger pipe to form a CO.sub.2 circulation path; an on-off valve in the heat exchanger pipe to be closed during defrosting so that the CO.sub.2 circulation path is a closed circuit; a pressure adjusting unit for adjusting pressure of the CO.sub.2 refrigerant during defrosting; and a brine circuit as a first heating medium, in which the defrost system permits the CO.sub.2 refrigerant to naturally circulate in the closed circuit during defrosting by a thermosiphon effect.

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 CO.sub.2 refrigerant; and a refrigerant circuit for permitting the cooled and liquefied CO.sub.2 refrigerant to circulate to the heat exchanger pipe. The defrost system includes a bypass pipe of the heat exchanger pipe to form a CO.sub.2 circulation path; an on-off valve in the heat exchanger pipe to be closed during defrosting so that the CO.sub.2 circulation path is a closed circuit; a pressure adjusting unit for adjusting pressure of the CO.sub.2 refrigerant during defrosting; and a brine circuit as a first heating medium, in which the defrost system permits the CO.sub.2 refrigerant to naturally circulate in the closed circuit during defrosting by a thermosiphon effect.

A packaged, pumped liquid, recirculating refrigeration system with charges of 10 lbs or less of refrigerant per ton of refrigeration capacity. The compressor and related components are situated in a pre-packaged modular machine room, and in which the condenser is mounted on the machine room and the evaporator is close coupled to the pre-packaged modular machine room. Prior art large receiver vessels may be replaced with a single or dual phase cyclonic separator also housed in the pre-packaged modular machine room.

A packaged, pumped liquid, recirculating refrigeration system with charges of 10 lbs or less of refrigerant per ton of refrigeration capacity. The compressor and related components are situated in a pre-packaged modular machine room, and in which the condenser is mounted on the machine room and the evaporator is close coupled to the pre-packaged modular machine room. Prior art large receiver vessels may be replaced with a single or dual phase cyclonic separator also housed in the pre-packaged modular machine room.

A freezing and refrigerating device comprises a box body and a door body. An air supply path supplying cooling air flow to a storage compartment, an air return path enabling the air flow from the storage compartment to pass, a cooling chamber and an air discharging path are defined in the box body, wherein the cooling chamber communicates with the air supply path and the air return path, and contains an evaporator, a blower and a defrosting heater, and the air discharging path communicates with the cooling chamber and an ambient space. The air supply path and the air discharging path are respectively provided with an air supply door and an air discharging door for selectively connecting or blocking the air supply path and the air return path. The present invention further provides a defrosting control method of the freezing and refrigerating device.

An apparatus and a method of defrosting frozen items, is provided. The apparatus and method utilizes a fluid flow system and method, such as a fluid-push/pull system in which generally an entire volume of fluid is pushed or pulled through a cavity in which frozen items are located and/or a continuous motion system in which fluid is circulated within a fluid tank of the system.

A method for thawing of a transport transporting bulk material includes providing water vapor, introducing water vapor into a thawing chamber. The transport transporting bulk material and to be thawed is at least partially located in the thawing chamber. Air loaded with the water vapor and having a preset dew point temperature T.sub.T is generated in the thawing chamber, and the dew point temperature T.sub.T is adapted to the transport transporting bulk material.

Provided are a refrigerator and a control method thereof. The refrigerator according to the embodiment includes a compressor configured to compress a refrigerant; a condenser configured to condense the refrigerant compressed by the compressor; a flow control part disposed at an exit side of the condenser to switch a flow direction of the refrigerant condensed by the condenser; a plurality of branch pipes configured to extend from the flow control part; an expander installed at the plurality of the branch pipes to depressurize the refrigerant; a plurality of evaporators connected to the plurality of branch pipes; and a bypass pipe configured to extend from an exit side of one of the plurality of evaporators to an entrance side of the other evaporator and having a bypass expander installed thereat to depressurize the refrigerant.

Provided are a refrigerator and a control method thereof. The refrigerator according to the embodiment includes a compressor configured to compress a refrigerant; a condenser configured to condense the refrigerant compressed by the compressor; a flow control part disposed at an exit side of the condenser to switch a flow direction of the refrigerant condensed by the condenser; a plurality of branch pipes configured to extend from the flow control part; an expander installed at the plurality of the branch pipes to depressurize the refrigerant; a plurality of evaporators connected to the plurality of branch pipes; and a bypass pipe configured to extend from an exit side of one of the plurality of evaporators to an entrance side of the other evaporator and having a bypass expander installed thereat to depressurize the refrigerant.

A refrigerator is provided that includes a cabinet having a refrigerating compartment cooled by a refrigerating compartment evaporator and a refrigerating compartment fan, and a freezing compartment cooled by a freezing compartment evaporator and a freezing compartment fan. A filler is provided on one of pair of doors to shield a gap between the pair of doors when the pair of doors are closed, a filler heater is provided inside the filler, and a controller is configured to control operations of the refrigerating compartment fan, the freezing compartment fan, the filler heater, and a compressor. When the refrigerating compartment evaporator performs a defrosting operation, the controller turns on the refrigerating compartment fan and the filler heater in state in that the compressor turns off so that heated air inside the refrigerating compartment is circulated to pass through the refrigerating compartment evaporator.