GAS TURBINE STARTING PROCESS
First Claim
1. A process for starting a gas turbine engine comprising:
- determining an ignition speed for the gas turbine engine that produces a particular air mass flow rate in a combustion section of the gas turbine engine;
accelerating or decelerating the gas turbine engine to a rotation speed within ±
5% of the ignition speed, which defines a start of an ignition window;
energizing at least one igniter in the combustion section of the gas turbine engine;
supplying a fuel flow to the combustion section of the gas turbine engine;
determining a completion of ignition in the combustion section, wherein said completion defines an end of the ignition window;
maintaining the rotation speed within ±
7% of the ignition speed during the ignition window; and
after the ignition window end, increasing the fuel flow to the combustion section to accelerate the gas turbine engine to an operating speed.
1 Assignment
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Accused Products
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.
39 Citations
20 Claims
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1. A process for starting a gas turbine engine comprising:
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determining an ignition speed for the gas turbine engine that produces a particular air mass flow rate in a combustion section of the gas turbine engine; accelerating or decelerating the gas turbine engine to a rotation speed within ±
5% of the ignition speed, which defines a start of an ignition window;energizing at least one igniter in the combustion section of the gas turbine engine; supplying a fuel flow to the combustion section of the gas turbine engine; determining a completion of ignition in the combustion section, wherein said completion defines an end of the ignition window; maintaining the rotation speed within ±
7% of the ignition speed during the ignition window; andafter the ignition window end, increasing the fuel flow to the combustion section to accelerate the gas turbine engine to an operating speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A process for starting a gas turbine engine (GT) comprising the steps of:
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measuring an ambient air temperature and an ambient air pressure; determining an ignition speed of the GT based on the ambient air temperature and the ambient air pressure; accelerating or decelerating the GT to within ±
5% of the ignition speed, which defines a start of an ignition window;providing ignition energy to a combustion section of the GT; supplying a fuel flow to the combustion section at a rate dependent on a fuel type and a fuel temperature to achieve a particular air/fuel ratio in the combustion section; holding the GT within ±
7% of the ignition speed until detecting a completion of ignition, which defines an end time of the ignition window;increasing the fuel flow to accelerate the GT to a full speed; and adjusting the fuel flow to keep a further temperature in the GT within a limit. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A process for starting a gas turbine engine comprising:
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setting an ignition speed based on ambient air conditions; and maintaining a rotation speed at the ignition speed during an ignition window until a completion of ignition prior to an acceleration to an operating speed. - View Dependent Claims (20)
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Specification