Patent ID: 8261529

Claim:
A combustor comprising: two upstream parts of fuel supply system for supplying gaseous fuels of two types having different heating values from each other; a three-way fuel transfer valve for merging the two upstream parts of fuel supply system with each other; a plurality of gaseous fuel supply subsystems for supplying a combustion chamber with the gaseous fuels supplied through the three-way fuel transfer valve; a plurality of burners for injecting, corresponding to each of the gaseous fuel supply subsystems, the gaseous fuel supplied from the gaseous fuel supply subsystem into the combustion chamber; and a low Btu gas-exclusive subsystem disposed in parallel with the gaseous fuel supply subsystems, wherein: the low Btu gas-exclusive subsystem includes: a gaseous fuel flow control valve for adiusting the flow rate of the low Btu gas; a gas shutoff valve disposed upstream of the gaseous fuel flow control valve; and a purge subsystem disposed downstream of the gaseous fuel flow control valve.