PURPOSE: To achieve higher efficiency by providing a control valve on bypass piping for bypassing compressed air to an port of an air compressor to decrease an Nox generation quantity while wasting no heat value.
CONSTITUTION: After the removal of dust with a ceramic filter 7, a high temperature and high pressure gas generated by a pressurized fluidized bed boiler 2 turns a gas turbine 3 to convert heat energy to mechanical energy and the gas with the pressure thereof approaching atmospheric pressure and with the temperature lowered undergoes a heat exchange with water and a steam system by a stack gas cooler 5 to be discharged from a stack 12. The air pressurized at an outlet of an air compressor 4 is recirculated to an inlet or an outlet of an air filter 15 to mix through an air control valve 13 and pressurized with the air compressor 4 via an IGV. Thus, the temperature of the air introduced into the compressor passing through the IGV rises to allow reduction in the mass of the air to be supplied to the pressurized fluidized bed boiler thereby enabling the supplying of the amount of air to match a load by recirculation.
SHINODA KATSUHIKO
KOGA TSUTOMU
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