Heat pump apparatus

A heat pump apparatus comprising:

• a plurality of indoor units;
• at least one outdoor unit having a cooling capacity (kW) of 10 kW or more and less than 40 kW;
• a refrigerant circulating between the plurality of indoor units and the at least one outdoor unit, the refrigerant being a mixed refrigerant of HFO-1123 and an HFC refrigerant other than HFO-1123;
• a main gas pipe communicating between the plurality of indoor units and the at least one outdoor unit;
• and
• a main liquid pipe communicating between the plurality of indoor units and the at least one outdoor unit,
• the main gas pipe and the at least one outdoor unit being configured to satisfy the following formula (1), and the liquid pipe and the at least one outdoor unit being configured to satisfy the following formula (2):
• 0.40≦an outer diameter φ(mm) of the main gas pipe/the cooling capacity (kW) of the at least one outdoor unit≦3.49 (1)
• 0.16≦an outer diameter φ(mm) of the main liquid pipe/the cooling capacity (kW) of the at least one outdoor unit≦1.91 (2)

A heat pump apparatus comprising:

• a plurality of indoor units;
• at least two outdoor units, the at least two outdoor units having a total cooling capacity (kW) of 40 kW or more and less than 70 kW;
• a refrigerant circulating between the plurality of indoor units and the at least two outdoor units, the refrigerant being a mixed refrigerant of HFO-1123 and an HFC refrigerant other than HFO-1123;
• a main gas pipe communicating between the plurality of indoor units and the at least two outdoor units;
• and
• a main liquid pipe communicating between the plurality of indoor units and the at least two outdoor units,
• the main gas pipe and the at least two outdoor units being configured to satisfy the following formula (1), and the main liquid pipe and the at least two outdoor units being configured to satisfy the following formula (2):
• 0.32≦an outer diameter φ(mm) of the main gas pipe/the total cooling capacity (kW) of the at least two outdoor units≦1.11 (1)
• 0.14≦an outer diameter φ(mm) of the main liquid pipe/the total cooling capacity (kW) of the at least two outdoor units≦0.56 (2)

A heat pump apparatus comprising:

• a plurality of indoor units;
• at least three outdoor units having a total cooling capacity (kW) of 70 kW or more and less than 100 kW;
• a refrigerant circulating between the plurality of indoor units and the at least three outdoor units, the refrigerant being a mixed refrigerant of HFO-1123 and an HFC refrigerant other than HFO-1123;
• a main gas pipe communicating between the plurality of indoor units and the at least three outdoor units;
• and
• a liquid pipe communicating between the plurality of indoor units and the at least three outdoor units,
• the main gas pipe and the at least three outdoor units being configured to satisfy the following formula (1), and the liquid pipe and the at least three outdoor units being confiugured to satisfy the following formula (2):
• 0.25≦an outer diameter φ(mm) of the main gas pipe/the total cooling capacity (kW) of the plurality of indoor units≦0.73 (1)
• 0.13≦an outer diameter φ(mm) of the liquid pipe/the total cooling capacity (kW) of the plurality of indoor units≦0.36 (2)