Powder supply hopper pressurizing apparatus, gasifier unit, integrated gasification combined cycle and control method of powder supply hopper pressurizing apparatus

A control method of a powder supply hopper pressurizing apparatus comprising:

• a first buffer tank in which pressurizing gas to be supplied to a powder supply hopper that supplies pressurized powder fuel is configured to be accumulated at a predetermined pressure,
• a second buffer tank that is provided in parallel with the first buffer tank and in which the pressurizing gas to be supplied to the powder supply hopper is configured to be accumulated at a predetermined pressure,
• a gas supply system connected to the powder supply hopper, configured to supply the pressurizing gas toward the powder fuel stored in the powder supply hopper when supplying the pressurized powder fuel,
• a pressurizing gas manufacturing device that is configured to supply the pressurizing gas to the first buffer tank, the second buffer tank and the gas supply system,
• a first buffer tank inlet valve provided on a pressurizing gas manufacturing device side of the first buffer tank,
• a first buffer tank outlet valve provided on a powder supply hopper side of the first buffer tank,
• a second buffer tank inlet valve provided on a pressurizing gas manufacturing device side of the second buffer tank, and
• a second buffer tank outlet valve provided on a powder supply hopper side of the second buffer tank,
• the control method of the powder supply hopper pressurizing apparatus, comprising:
• controlling the first buffer tank to pressurize the powder supply hopper to a first pressure, and then controlling the second buffer tank to pressurize the powder supply hopper to a second pressure, and
• in a case where it is determined that the powder supply hopper cannot be pressurized to the first pressure by use of the pressurizing gas accumulated in the first buffer tank, pressurizing the powder supply hopper to the second pressure by use of the second buffer tank and the gas supply system, and
• in a case where it is determined that the powder supply hopper cannot be pressurized to the second pressure by use of the pressurizing gas accumulated in the second buffer tank, pressurizing the powder supply hopper to the second pressure by use of the first buffer tank and the gas supply system,
• determining that the first buffer tank is non-usable when the first buffer tank inlet valve or the first buffer tank outlet valve becomes out of order, indicates an abnormality, and does not operate, and
• determining that the second buffer tank is non-usable when the second buffer tank inlet valve or the second buffer tank outlet valve becomes out of order, indicates an abnormality, and does not operate.