CO2 COOLING AND HEATING APPARATUS AND METHOD HAVING MULTIPLE REFRIGERATING CYCLE CIRCUITS

摘要

A CO₂ cooling and heating apparatus and method permit simultaneous production of high-temperature heat source and low-temperature heat source having a temperature difference therebetween. The apparatus/method uses CO₂ (carbon dioxide) as a refrigerant, and has a first refrigerating cycle circuit where the refrigerant is compressed to a supercritical zone and then decompressed via an expansion device to a pressure/temperature level of the CO₂ triple point or below to thereby attain evaporation. The apparatus can include multistage compressors, intermediate cooler disposed in a first refrigerant flow path between a condenser and the expansion device. A second refrigerating cycle circuit having a second refrigerant flow path, which can branch off from the first refrigerant flow path or provided in an independent closed circuit, can be provided to carry out absorption of evaporation latent heat with the first refrigerant flow path to thereby maintain the pressure/temperature level of the CO₂ triple point (Ptr) or above. A third refrigerating cycle circuit having a third refrigerant flow path also can be provided to carry out heat exchange with the second refrigerant flow path.