Pulverized-fuel supply unit and method, and integrated gasification combined cycle

A pulverized-fuel supply unit comprising:

• a hopper having a hollow shape to store therein pulverized fuel;
• a plurality of first nozzles provided to the hopper;
• a plurality of second nozzles provided to a vertically lower part of the hopper below the plurality of first nozzles;
• a pressurizing-gas supply device configured to supply pressurizing gas to increase internal pressure of the hopper;
• a fluidization-gas supply device configured to supply fluidization gas to fluidize the pulverized fuel in the hopper;
• and
• a pulverized-fuel supply line provided to a vertically lower part of the hopper, wherein
• the pressurizing-gas supply device supplies pressurizing gas to the plurality of first nozzles and the plurality of second nozzles,
• the fluidization-gas supply device supplies fluidization gas to the plurality of first nozzles and the plurality of second nozzles, and
• the pulverized-fuel supply unit includes
• a controller configured to cause the fluidization-gas supply device to stop injection of fluidization gas from the plurality of first nozzles when the amount of the pulverized fuel in the hopper decreases below a predetermined lower limit during conveyance of pulverized fuel from the hopper.

A pulverized-fuel supplying method performed in a pulverized-fuel supply unit that, includes a hopper having a hollow shape to store therein pulverized fuel;

• a plurality of first nozzles provided to the hopper;
• a plurality of second nozzles provided to a vertically lower part of the hopper below the plurality of first nozzles;
• a pressurizing-gas supply device configured to supply pressurizing gas to increase internal pressure of the hopper;
• a fluidization-gas supply device configured to supply fluidization gas to fluidize the pulverized fuel in the hopper;
• and a pulverized-fuel supply line provided to a vertically lower part of the hopper, the pressurizing-gas supply device supplying pressurizing gas to the first nozzles and the second nozzles, the fluidization-gas supply device supplying fluidization gas to the second nozzles, the method comprising:
• activating the pressurizing-gas supply device when pressure is applied into the hopper;
• and
• activating the fluidization-gas supply device when the pulverized fuel is conveyed from the hopper.