Patent attributes
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. The above ammonia/CO2 refrigerating system allows a refrigeration cycle of a combination of an ammonia cycle and a CO2 cycle to be formed with no care, even when a refrigerating showcase, which is the cooler side of the CO2 cycle, is installed at an arbitrary place.
