GAS TURBINE COMBUSTION MACHINE AND OPERATION THEREOF

PURPOSE:To provide a structure of a combustion machine and its operating method in which a pre-mixing combustion technology for a high temperature of a gas turbine combustion device and low NOx can be developed and in particular a stable pre-mixing combustion in a gas turbine operating range and a lean gas combustion for getting a low NOx can be stably carried out. CONSTITUTION:A combustion device is comprised of a pre-mixing burner 4 at a head part of a combustion chamber 29, an auxiliary burner 5 at its central axis and a bypassing mechanism cooperating with an inner flow rate adjusting ring 21 to cause air at the pre-mixing burner to be variable. During a period ranging from a starting of ignition to non-loading state, a partial dispersing combustion condition is carried out with excessive fuel for an amount of air at the auxiliary burner 5, a fuel control is carried out to perform an instantaneous lean pre-mixing combustion at the time of feeding fuel to the pre-mixing burner 4 under no load and the lean mixing combustion is continued under a fuel-air ratio control operation of the pre-mixing burner 4 when the load is increased so as to realize a low NOx state. With such an arrangement, the fuel-air ratio control operation for the pre-mixing combustion becomes easy.