Liquid fuel and water injection purge systems and method for a gas turbine having a three-way purge valve
AssigneeGeneral Electric Company
InventorsRobert Scott Traver, Robert Joseph Iasillo, Howard Jay Kaplan, Troy Joseph Schroeder, Christopher John Morawski
Life of this patent
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Abstract
A liquid fuel purge system is disclosed for flushing liquid fuel from the combustion chambers of a gas turbine. The liquid purge system includes a three-way valve to pass liquid fuel and, alternatively, purge air to the combustion chambers. The gas turbine may operate on liquid fuel or gaseous fuel. When the turbine is switched to burn gaseous fuel, the liquid fuel remaining in the liquid fuel system is flushed by purge air provided by a liquid fuel purge system.
Claims30
A gas turbine comprising:
- a main compressor, a combustor and a turbine;
- a liquid fuel supply coupled to provide liquid fuel to the combustor;
- a gaseous fuel supply coupled to provide gaseous fuel to the combustor;
- a liquid fuel purge system further comprising:
- a purge manifold;
- a coupling to a compressor air discharge port of the main compressor to draw compressor air into the purge system;
- a conduit between the discharge port and the purge manifold through which passes compressor air to the purge manifold, and
- a valve alternatively coupling the manifold and liquid fuel supply to the combustor, said valve including an actuator coupled to said fuel supply, and said valve having a purge setting in which purge air passes through the valve to the combustor and a liquid fuel setting in which liquid fuel passes through the valve to the combustor,
- wherein said valve has a passive switch mode in which said valve is switched to said fuel setting by liquid fuel pressure applied to said actuator and an active switch mode in which said valve is maintained in said fuel setting, during a high fuel flow condition, by an external force applied to the actuator.
A gas turbine comprising:
- a main compressor, a combustor and a turbine;
- a liquid fuel supply coupled to provide liquid fuel to the combustor;
- a gaseous fuel supply coupled to provide gaseous fuel to the combustor;
- a liquid fuel purge system further comprising:
- a purge manifold;
- a coupling to a compressor air discharge port of the main compressor to draw compressor air into the purge system;
- a conduit between the discharge port and the purge manifold through which passes compressor air to the purge manifold,
- a valve alternatively coupling the manifold and liquid fuel supply to the combustor, said valve including an actuator coupled to said fuel supply, and said valve having a purge setting in which purge air passes through the valve to the combustor and a liquid fuel setting in which liquid fuel passes through the valve to the combustor, wherein said valve is switched to said fuel setting by liquid fuel pressure applied to said actuator,
- wherein valve further includes a spring providing a bias towards said purge setting and said fuel pressure applied to said actuator is sufficient to overcome said bias, and
- wherein the fuel setting blocks purge air from flowing to the combustor, and the purge setting blocks liquid fuel from flowing to the combustor.
A gas turbine comprising:
- a main compressor, a combustor with a plurality of combustion chambers, and a turbine;
- a liquid fuel supply providing liquid fuel to the combustor;
- a liquid fuel purge system including a purge manifold and a source of purge air coupled to the purge manifold, and
- a plurality of valves, each of said valves alternatively coupling the purge manifold and the liquid fuel supply to one of the combustion chambers, said valves each including an actuator coupled to said fuel supply, and each of said valves having a purge setting in which purge air passes through the valve to the combustor and a fuel setting in which liquid fuel passes through the valve to the combustor, wherein the valve has a passive mode in which said valve is switched to said fuel setting by liquid fuel pressure applied to the actuator and said valve has an active mode in which said valve is maintained in said fuel setting by an external force applied to the actuator.
A method for purging a gas turbine having a main compressor providing compressed air to a combustor which generates hot gases to drive a turbine, and the combustor is fueled by a liquid fuel system, wherein the method comprises the steps of:
- a. supplying liquid fuel to the combustor and burning the liquid fuel to generate the hot combustion gases, where the liquid is supplied to the combustor through a valve;
- b. switching from supplying liquid fuel to the combustor to supplying another type of fuel;
- c. purging liquid fuel from the liquid fuel system by directing compressed air via said valve to the combustor,
- d. switching the valve to pass liquid fuel to the combustor during step (a) by application of liquid fuel pressure to the valve,
- e. maintaining the valve to pass liquid fuel by application of an external force to the valve, during a high fuel flow condition.
A method for supplying liquid fuel and purge air to a combustor of a gas turbine, wherein the combustor is fueled alternatively by a liquid fuel system and a gaseous fuel system and the method comprises the steps of:
- a. supplying liquid fuel to the combustor and burning the liquid fuel to generate the hot combustion gases, where the liquid is supplied to the combustor through a valve;
- b. switching the valve from supplying liquid fuel to supplying purge air to the combustor by reducing liquid fuel pressure applied to actuate the valve,
- c. switching the valve from supplying purge air to supplying liquid fuel by increasing liquid fuel pressure applied to actuate the valve, and
- d. during high liquid fuel flow, applying an external force to the valve to maintain the liquid fuel flow through the valve.
Dependencies are inferred from the claim text.