Power plant

A power plant comprising:

• a vaporizer configured to exchange heat between a medium having a lower boiling point than water and a geothermal heat source to generate a medium gas;
• a turbine configured to receive a pressure of the medium gas supplied from the vaporizer to rotate;
• an electric generator configured to be connected to the turbine;
• a condenser configured to cool the medium gas discharged from the turbine, a cooling source of the condenser being the atmosphere;
• a circulation pump configured to supply the medium discharged from the condenser to the vaporizer;
• a medium flow path configured to pass through the vaporizer, the turbine, the condenser, and the circulation pump;
• and
• an air removing device configured to remove air intruding into the medium, the air removing device comprising:
• a gas retaining portion provided on an outlet side of the condenser and configured to retain a gas in the medium,
• a pressure gauge configured to measure a pressure in the gas retaining portion,
• a thermometer configured to measure a temperature in the gas retaining portion,
• a controller configured to calculate a pressure threshold value based on a saturated vapor pressure value of the medium calculated using the temperature of the thermometer, and compare a pressure value of the pressure gauge and the pressure threshold value to determine whether or not the air has intruded into the medium, and
• a releaser configured to release the gas in the gas retaining portion when it is determined that the air has intruded, the releaser including
• a first chamber to which the gas retained in the gas retaining portion is transferred when the controller determines that the air has intruded,
• a medium supplier configured to supply a liquid medium to the first chamber to compress the gas, the gas remaining in the first chamber being released after the medium is supplied, the medium supplier including
• a liquid medium tank configured to store the liquid medium, and
• a liquid medium feed pump configured to supply the liquid medium from the liquid medium tank to an inside of the first chamber,
• a first valve provided in a pipe connecting the gas retaining portion and a lower portion of the first chamber,
• a second valve provided in a pipe connecting the liquid medium feed pump and the first chamber,
• a third valve provided in a pipe connecting an upper portion of the first chamber to a second chamber,
• a fourth valve configured to release the gas from the second chamber, and
• a fifth valve provided in a pipe connecting the gas retaining portion to the upper portion of the first chamber.