Abstract: A refrigerant heat exchanger is provided and includes: a hollow container having a cylindrical shape; a plate stack disposed on an inner lower side of the hollow container, including plates each having a front side and a back side with a plurality of concavo-convex portions formed thereon which are stacked to form a first heat exchange flow passage through which a first refrigerant flows and a second heat exchange flow passage through which a second refrigerant flows; a supply pipe disposed in an interior space of the hollow container above the plate stack and configured to supply the first refrigerant to the plate stack; and a discharge pipe configured to exchange heat between the first refrigerant supplied from the supply pipe and the second refrigerant flowing through the plate stack and to discharge the first refrigerant.

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 refrigerant heat exchanger is provided and includes: a hollow container having a cylindrical shape; a plate stack disposed on an inner lower side of the hollow container, including plates each having a front side and a back side with a plurality of concavo-convex portions formed thereon which are stacked to form a first heat exchange flow passage through which a first refrigerant flows and a second heat exchange flow passage through which a second refrigerant flows; a supply pipe disposed in an interior space of the hollow container above the plate stack and configured to supply the first refrigerant to the plate stack; and a discharge pipe configured to exchange heat between the first refrigerant supplied from the supply pipe and the second refrigerant flowing through the plate stack and to discharge the first refrigerant.

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: An ammonia/CO2 refrigeration system is provided in which the ammonia cycle and CO2 brine cycle can be combined without problems even when refrigeration load such as refrigerating showcase, etc. is located at any place in accordance with circumstances of customer's convenience. The system comprises apparatuses working on an ammonia refrigerating cycle, a brine cooler for cooling and condensing CO2 by utilizing the latent heat of vaporization of the ammonia, and a liquid pump provided in a supply line for supplying the cooled and liquefied CO2 to a refrigeration load side cooler, wherein said liquid pump is a variable-discharge pump for allowing CO2 to be circulated forcibly, and the forced circulation flow is determined so that CO2 is recovered from the outlet of the cooler of the refrigeration load side in a liquid or liquid/gas mixed state.

Abstract: An ammonia/CO2 refrigerating system having a liquid pump for feeding the liquid CO2 cooled in a brine cooler by the utilization of the vaporization latent heat of ammonia in an ammonia refrigeration cycle to a cooler, which comprises a liquid receiving vessel 4 for receiving a CO2 brine cooled in a brine cooler 3, a liquid pump 5 capable of changing the rate of the feed of a liquid, a rising piping 90 provided between the liquid pump 5 and a cooler 6, and a communication pipe 100 for communicating the top of the riser pipe 90 with the CO2 gas phase in the liquid receiving vessel 4, wherein the discharge pressure of the liquid pump 5 is set so as for the CO2 recovered form the cooler 3 or the liquid receiver 4 in the state of a liquid or a gas-liquid mixture, and the level of the rise in the rising piping 90 is set at a level being the same as or higher than the highest storage level for the CO2 brine in the liquid receiving vessel 4.

Abstract: An ammonia/CO2 refrigerating system having a liquid pump for feeding the liquid CO2 cooled in a brine cooler by the utilization of the vaporization latent heat of ammonia in an ammonia refrigeration cycle to a cooler, which comprises a liquid receiving vessel 4 for receiving a CO2 brine cooled in a brine cooler 3, a liquid pump 5 capable of changing the rate of the feed of a liquid, a rising piping 90 provided between the liquid pump 5 and a cooler 6, and a communication pipe 100 for communicating the top of the riser pipe 90 with the CO2 gas phase in the liquid receiving vessel 4, wherein the discharge pressure of the liquid pump 5 is set so as for the CO2 recovered form the cooler 3 or the liquid receiver 4 in the state of a liquid or a gas-liquid mixture, and the level of the rise in the rising piping 90 is set at a level being the same as or higher than the highest storage level for the CO2 brine in the liquid receiving vessel 4.

Abstract: The object of the invention is to provide an ammonia/CO2 refrigeration system in which the ammonia cycle and CO2 brine cycle can be combined without problems even when refrigeration load such as refrigerating showcase, etc. is located at any place in accordance with circumstances of customer's convenience. The system comprises apparatuses working on an ammonia refrigerating cycle, a brine cooler for cooling and condensing CO2 by utilizing the latent heat of vaporization of the ammonia, and a liquid pump provided in a supply line for supplying the cooled and liquefied CO2 to a refrigeration load side cooler, wherein said liquid pump is a variable-discharge pump for allowing CO2 to be circulated forcibly, and the forced circulation flow is determined so that CO2 is recovered from the outlet of the cooler of the refrigeration load side in a liquid or liquid/gas mixed state.