Booster system

A booster system for increasing pressure of an object gas to pressure equal to or higher than target pressure that is higher than critical pressure, comprising:

• a first compression unit that:
• has a multistage configuration in which a plurality of impellers are interlocked with one another, and
• compresses the object gas to intermediate pressure equal to or higher than the critical pressure and lower than the target pressure and generates an intermediate supercritical fluid;
• a heat exchanger that cools the intermediate supercritical fluid with a cooling medium and generates an intermediate supercritical pressure liquid;
• a liquid extracting and pressure reducing unit that extracts a part of the intermediate supercritical pressure liquid;
• a first flow regulating valve that regulates a flow rate of the extracted part of the intermediate supercritical pressure liquid when supplied into the heat exchanger, wherein the extracted part of the intermediate supercritical pressure liquid serves as the cooling medium;
• a second flow regulating valve that regulates a suction flow rate of the object gas sucked into one of the impellers of the first compression unit;
• a second compression unit that increases pressure of the rest of the intermediate supercritical pressure liquid to be equal to or higher than the target pressure;
• a first pressure sensor that detects pressure of the intermediate supercritical pressure liquid on an inlet side of the second compression unit;
• and
• a second pressure sensor that detects pressure on an outlet side of the second compression unit,
• wherein the object gas is carbon dioxide,
• wherein an opening degree of the first flow regulating valve is regulated based on a detection result of the first pressure sensor, and
• wherein an opening degree of the second flow regulating valve is regulated based on a detection result of the second pressure sensor.