Method for operating a gas turbine plant

摘要

A gas turbine plant has a compressor (2), a first combustion chamber (6) followed by a high pressure turbine (4), a second combustion chamber (10) and a low pressure turbine (5). In the first combustion chamber (6) a first gaseous fuel (8) is injected and combusted, generating first hot gases (9) that are at least partly expanded in the high pressure turbine (4), and in the second combustion chamber (10) a second fuel (11) is injected in the at least partly expanded hot gases generated in the first combustion chamber (6) and combusted, generating second hot gases (12) that are expanded in the low pressure turbine (5). In the first combustion chamber (6) water is also injected to increase the gas turbine plant power output. In the first combustion chamber (6) a water flow rate is injected compatible with a predetermined flame stability limit. In the second combustion chamber (6) the flame temperature is regulated to burn the non-combusted products generated in the first combustion chamber (6) to bring their amount below a predetermined emission limit, without exceeding a predetermined NOx emission limit.

主权项

1. A method for operating a gas turbine plant having a compressor, a first combustion chamber followed by a high pressure turbine, a second combustion chamber, and a low pressure turbine, the method comprising:
defining a prefixed emission limit for the gas turbine plant; injecting and combusting a first gaseous fuel in the first combustion chamber, generating first hot gases and non-combusted products above the prefixed emission limit; at least partly expanding the first hot gases in the high pressure turbine; injecting and combusting a second fuel in the at least partially expanded first hot gases in the second combustion chamber, generating second hot gases; expanding the second hot gases in the low pressure turbine; injecting water at least in the first combustion chamber to increase the gas turbine plant power output; wherein injecting water comprises injecting in the first combustion chamber at a water flow rate such that flame stability in the first combustion chamber does not pass a predetermined flame stability limit; and regulating flame temperature in the second combustion chamber to burn non-combusted products generated in the first combustion chamber to bring the amount of non-combusted products below a predetermined emission limit, and without exceeding a predetermined NOx emission limit.