Fuel supply system for gas turbine combustor and fuel supply method for gas turbine combustor

摘要

A consumption amount of high-calorific gas such as coke oven gas (COG) during operation of a gas turbine is reduced, halt of the gas turbine due to clogging of a pilot system, a malfunction of a compressor which compresses high-calorific gas is prevented, and reliability of the gas turbine is improved. When operation of the gas turbine (11) starts, with use of both a first fuel supply system (31) which supplies a high-calorific fuel for a first nozzle constituting a combustor (17), and a second fuel supply system (32) which supplies a low-calorific fuel for a second nozzle constituting the combustor (17), the high-calorific fuel and the low-calorific fuel are supplied to the combustor (17), and at a time when the gas turbine (11) reaches output power which enables continuous operation with only the low-calorific fuel, supply of the high-calorific fuel to the combustor (17) is shut off, and only the low-calorific fuel is supplied to the combustor (17).

主权项

1. A fuel supply method for a gas turbine combustor which supplies at least two kinds of fuels different in calorie to the gas turbine combustor,
wherein at a time of start of operation of a gas turbine, with use of both a first fuel supply system which supplies a high-calorific fuel for a first nozzle constituting the gas turbine combustor, and a second fuel supply system which supplies a low-calorific fuel for a second nozzle constituting the gas turbine combustor, the high-calorific fuel and the low-calorific fuel are supplied to the gas turbine combustor, at a time point when the gas turbine reaches output power which enables continuous operation with only the low-calorific fuel, supply of the high-calorific fuel to the gas turbine combustor is shut off, and only the low-calorific fuel is supplied to the gas turbine combustor, when supply of the high-calorific fuel to the gas turbine combustor is shut off, and only the low-calorific fuel is supplied to the gas turbine combustor, the low-calorific fuel guided through the second fuel supply system is guided to the first nozzle through a sweep line which guides the low-calorific fuel to a mid-portion of the first fuel supply system, and the low-calorific fuel is ejected from both the second nozzle and the first nozzle, and when the supply only of the low-calorific fuel supplied to the gas turbine combustor is finished, the high-calorific fuel is supplied at once, the supply of the low-calorific fuel to the first fuel supply system through the sweep line is shut off at once, and the operation of supplying the high-calorific fuel to the gas turbine combustor through the first fuel supply system and supplying the low-calorific fuel to the gas turbine combustor through the second fuel supply system is started.