| 摘要 |
<p>A refrigeration apparatus 2 in which at high ambient conditions the apparatus operates as a primary and secondary cascade refrigeration system with a carbon dioxide refrigeration circuit 3 providing the secondary refrigeration circuit, and at low ambient conditions the carbon dioxide refrigeration circuit operates in a subcritical mode and provides the primary refrigeration circuit. The refrigeration apparatus adapts between the high ambient temperature condition and the low ambient temperature condition by use of a converter to convert between the single stage subcritical CO2 refrigeration system and the multistage/cascade primary and secondary cascade refrigeration system, and the converter may be a switch to switch off the second stage of the apparatus or may be a flow diverter to divert the carbon dioxide flow. When in cascade mode, the primary refrigeration system 5 may use propane as the refrigerant, and the circuit may include a compressor 14, a condenser 16, an expansion device 18 and an evaporator 20, and the secondary refrigeration system has the CO2 refrigerant and includes a compressor 4, a condenser 6, an expansion device 8, an evaporator 10 and a cooler 12.</p> |
