Refrigeration system

A refrigeration system comprising:

• a turbo machine including:
• a rotating shaft;
• a compressor impeller attached to one side of the rotating shaft;
• a turbine wheel attached to the other side of the rotating shaft;
• an electric motor attached to the rotating shaft between the compressor impeller and the turbine wheel, the electric motor being configured to generate a rotational force to rotate the rotating shaft;
• and
• a casing configured to accommodate the rotating shaft, the compressor impeller, the turbine wheel, and the electric motor;
• a compressed fluid line for guiding a fluid compressed by the compressor impeller to the turbine wheel;
• a cooler provided in the compressed fluid line, the cooler being configured to perform heat exchange between the fluid flowing through the compressed fluid line and a cooling liquid;
• a cooling liquid circulation line for circulating the cooling liquid, the cooling liquid circulation line being provided with a cooling device for cooling the cooling liquid;
• and
• a cooling liquid introduction line for extracting the cooling liquid from the cooling liquid circulation line and introducing the cooling liquid into the casing, wherein
• the casing includes a motor compartment housing the electric motor,
• the refrigeration system further comprises:
• a cooling medium supply line having one end connected to the compressed fluid line downstream of the cooler, the cooling medium supply line being configured to extract the fluid from the compressed fluid line and supply the fluid into the motor compartment as a cooling medium for cooling the electric motor;
• and
• a cooling medium return line for returning the fluid supplied into the motor compartment through the cooling medium supply line to a fluid introduction line for guiding the fluid to the compressor impeller, and
• a minimum area of a flow path through which the cooling medium flows in the cooling medium return line is smaller than a minimum area of a flow path through which the cooling medium flows in the cooling medium supply line.

A refrigeration system comprising:

• a turbo machine including:
• a rotating shaft;
• a compressor impeller attached to one side of the rotating shaft;
• a turbine wheel attached to the other side of the rotating shaft;
• an electric motor attached to the rotating shaft between the compressor impeller and the turbine wheel, the electric motor being configured to generate a rotational force to rotate the rotating shaft;
• and
• a casing configured to accommodate the rotating shaft, the compressor impeller, the turbine wheel, and the electric motor;
• a compressed fluid line for guiding a fluid compressed by the compressor impeller to the turbine wheel;
• a cooler provided in the compressed fluid line, the cooler being configured to perform heat exchange between the fluid flowing through the compressed fluid line and a cooling liquid;
• a cooling liquid circulation line for circulating the cooling liquid, the cooling liquid circulation line being provided with a cooling device for cooling the cooling liquid, and
• a cooling liquid introduction line for extracting the cooling liquid from the cooling liquid circulation line and introducing the cooling liquid into the casing, wherein
• the casing includes a motor compartment housing the electric motor,
• the refrigeration system further comprises:
• a cooling medium supply line having one end connected to the compressed fluid line downstream of the cooler, the cooling medium supply line being configured to extract the fluid from the compressed fluid line and supply the fluid into the motor compartment as a cooling medium for cooling the electric motor;
• and
• a cooling medium return line for returning the fluid supplied into the motor compartment through the cooling medium supply line to a fluid introduction line for guiding the fluid to the compressor impeller,
• the casing is provided with a compressor-side communication hole allowing communication between a motor compartment housing the electric motor and a compressor-side storage space housing the compressor impeller, the rotating shaft being inserted through the compressor-side communication hole,
• the refrigeration system further comprises:
• a compressor-side bearing disposed in the compressor-side communication hole and configured to rotatably support the rotating shaft;
• and
• a compressor-side sealing portion configured to seal between the compressor-side communication hole and the rotating shaft on a side of the compressor-side communication hole closer to the compressor-side storage space than the compressor-side bearing,
• the cooling medium return line has a cooling medium intake port for drawing the cooling medium supplied into the motor compartment into the cooling medium return line, and
• the cooling medium intake port is formed between the compressor-side bearing and the compressor-side sealing portion in the compressor-side communication hole.