Abstract: A turbine engine combustion system is disclosed including a fuel nozzle assembly having three independently controlled stages of water injection. A first stage includes water mixed with a gaseous fuel upon inlet to the nozzle, where the first stage water mixes and travels with the gaseous fuel to be injected into a combustor. A second stage includes water injected into the combustor via a secondary liquid nozzle which is used for fuel oil during liquid fuel operation, but which may be used for the secondary water during gaseous fuel operation. A third stage includes water injected into the combustor via a plurality of nozzle holes known as an atomizing air cap. An algorithm and criteria are also defined for controlling the three stages of water injection to achieve the optimum balance of turbine operational criteria including NOx emissions, combustion dynamics and water impingement downstream of the nozzle.

Abstract: A turbine engine combustion system is disclosed including a fuel nozzle assembly having three independently controlled stages of water injection. A first stage includes water mixed with a gaseous fuel upon inlet to the nozzle, where the first stage water mixes and travels with the gaseous fuel to be injected into a combustor. A second stage includes water injected into the combustor via a secondary liquid nozzle which is used for fuel oil during liquid fuel operation, but which may be used for the secondary water during gaseous fuel operation. A third stage includes water injected into the combustor via a plurality of nozzle holes known as an atomizing air cap. An algorithm and criteria are also defined for controlling the three stages of water injection to achieve the optimum balance of turbine operational criteria including NOx emissions, combustion dynamics and water impingement downstream of the nozzle.

Abstract: A starting process for a gas turbine (28) that holds the turbine speed of rotation at an ignition speed setting during an ignition window (58), with the ignition speed setting being based on ambient air conditions to achieve a specified combustor air mass flow rate (52). A fuel flow rate may be set based on the fuel type and temperature to achieve a particular air/fuel ratio in a combustor. The fuel flow rate may be adjusted during the ignition window and thereafter based on a combustor inlet air temperature (46). Completion of ignition may be determined by a reduction (68) in a blade path temperature spread (66). After ignition, fuel flow is increased to accelerate the turbine to full speed. At any point, the fuel flow may be reduced, or its increase may be slowed, to avoid exceeding a temperature limit in the turbine.

Abstract: An ignition system for a combustor of a gas turbine engine is disclosed. The ignition system may include multiple igniters to reduce the likelihood of system failure. In at least one embodiment, the ignition system may be formed from a first igniter formed from an outer electrode containing at least one central electrode at a distal end of the outer electrode and may include a second igniter. The second igniter may be formed from a central electrode positioned within the outer electrode forming the first igniter. During operation, the igniters may spark to ignite the fuel mixture within the combustor.

Abstract: A starting process for a gas turbine (28) that holds the turbine speed of rotation at an ignition speed setting during an ignition window (58), with the ignition speed setting being based on ambient air conditions to achieve a specified combustor air mass flow rate (52). A fuel flow rate may be set based on the fuel type and temperature to achieve a particular air/fuel ratio in a combustor. The fuel flow rate may be adjusted during the ignition window and thereafter based on a combustor inlet air temperature (46). Completion of ignition may be determined by a reduction (68) in a blade path temperature spread (66). After ignition, fuel flow is increased to accelerate the turbine to full speed. At any point, the fuel flow may be reduced, or its increase may be slowed, to avoid exceeding a temperature limit in the turbine.