| 摘要 |
In a main circuit (12) of refrigerant circuitry (11), a liquid-side shutoff valve (23) is provided between a liquid receiver (19) and an indoor heat exchanger (20). Downstream of the liquid-side shutoff valve (23), a refrigerant charging section (40A) including a refrigerant charge valve (40) connectable with a refrigerant cylinder (31) is provided. The refrigerant circuitry (11) includes a pressure relieving circuit (SVP) for conducting refrigerant in a high-pressure-side line of the refrigerant circuitry (11) to a low-pressure-side line thereof in additional refrigerant charging operation executed by operating compressors (15, 22) with the liquid-side shutoff valve (23) closed. The refrigerant circuitry (11) further includes an injection circuit (SVT) for lowering the temperature of refrigerant discharged from the compressors (15, 22) by supplying low-temperature refrigerant flowing downstream of an outdoor electronic expansion valve (18) to the compressors (15, 22) when the superheating degree of the discharged refrigerant is larger than a first predetermined temperature. <IMAGE> |
