Cooling device, exposure device, and industrial equipment

A cooling device comprising:

• a first refrigeration cycle including a compressor configured to compress a refrigerant, a condenser configured to cool and condense the refrigerant compressed by the compressor, a first decompressor, a first evaporator, and an evaporation pressure regulating valve, and in which the refrigerant decompressed by the first decompressor flows to the first evaporator to cool a first cooling target;
• a second refrigeration cycle including the compressor, the condenser, a second decompressor, and a second evaporator, and in which a refrigerant having a flow rate larger than a flow rate of the first evaporator flows to the second evaporator to cool a second cooling target;
• and
• a control unit,
• wherein
• the first refrigeration cycle includes a common flow path in which the compressor and the condenser are connected sequentially and a first flow path in which the first decompressor, the first evaporator, and the evaporation pressure regulating valve are connected sequentially as viewed in a refrigerant flow direction,
• the second refrigeration cycle includes the common flow path, a second flow path in which the second decompressor and the second evaporator are connected sequentially, and a hot gas bypass that branches from the common flow path between the compressor and the condenser and is connected to the second flow path between the second decompressor and the second evaporator via a control valve as viewed in a refrigerant flow direction,
• the common flow path branches into the first flow path and the second flow path at a branch point positioned downstream of the condenser,
• the first flow path positioned downstream of the evaporation pressure regulating valve and the second flow path positioned downstream of the second evaporator merge at a junction and are connected to the common flow path positioned upstream of the compressor, and
• the control unit is configured to:
• control an opening/closing degree of the control valve of the hot gas bypass based on a temperature of the second cooling target cooled by the second evaporator,
• acquire a first degree of superheat, which is a degree of superheat of the refrigerant, from a temperature and/or a pressure of the refrigerant at a position downstream of the first evaporator in the first flow path, and control an opening/closing degree of the first decompressor based on the first degree of superheat,
• acquire a second degree of superheat, which is a degree of superheat of the refrigerant, from a temperature and/or a pressure of the refrigerant at a position downstream of the second evaporator in the second flow path, and control an opening/closing degree of the second decompressor based on the second degree of superheat, and
• control an opening/closing degree of the evaporation pressure regulating valve based on a target pressure of the refrigerant at a position downstream of the evaporation pressure regulating valve.