Valve apparatus for providing shutoff and overspeed protection in a gas turbine fuel system
First Claim
1. A valve pack for use in a fuel delivery system for providing a desired fuel flow to an engine, the fuel deliver system including a metering valve having a metering state where the metering valve provides a metered fuel flow to the engine in response to a pressure differential between a reference pressure chamber and a modulated pressure chamber of the valve and a shutoff state wherein the metering valve blocks fuel flow to the engine in response to a pressure differential between the reference and modulated pressure chambers;
- the valve pack comprising;
a fuel inlet port to receive a metered fuel flow from the fuel metering valve;
a fuel outlet port to selectively receive the metered fuel flow from the fuel inlet port to direct the metered fuel flow to the engine;
an actuation pressure inlet port selectively connected to a drain to transfer an actuation fuel flow to the drain;
a reference pressure inlet port to receive fuel flow at a reference pressure;
a reference pressure outlet port to selectively receive the fuel flow at the reference pressure form the reference pressure inlet port to transfer the fuel flow to a modulated pressure chamber of the fuel metering valve;
an overspeed activation port; and
a shutoff activation port;
the valve pack having an overspeed state in response to the overspeed activation port being placed in fluid communication with a drain, a shutoff state in response to the shutoff activation port being placed in fluid communication with a drain and flow from the overspeed activation port to the drain being blocked, and a run state with flow from both of the overspeed and shutoff activation ports to the drain being blocked;
with the valve pack in the overspeed state, the reference pressure inlet port is connected to the reference pressure outlet port to direct fuel flow at the reference pressure from the reference pressure inlet port to the modulated pressure chamber of the fuel metering valve, the actuation pressure inlet port is opened to receive a fuel flow, and flow from the fuel inlet port to the fuel outlet port is blocked to shutoff the metered fuel flow to the engine;
with the valve pack in the shutoff state, the actuation pressure inlet port is opened to receive a fuel flow, fuel flow from the reference pressure inlet port to the reference pressure outlet port is blocked, and fuel flow from the fuel inlet port to the fuel outlet port is blocked to shutoff the metered fuel flow to the engine;
with the valve pack in the run state, the fuel inlet port is connected to the fuel outlet port to direct the metered fuel flow from the fuel inlet port to the engine, fuel flow from the reference pressure inlet port to the reference pressure outlet port is blocked, and the actuation pressure inlet port is closed;
a first valve spool positioned in the valve pack to block fuel flow from the fuel inlet port to the fuel outlet port with the valve pack in the overspeed state and with the valve pack in the shutoff state; and
a second valve spool positioned in the valve pack to block fuel flow through the actuation pressure inlet port with the valve pack in the run state.
1 Assignment
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Accused Products
Abstract
Methods and apparatus are disclosed for providing shutoff, overspeed protection, and directional control of a bypass flow in a fuel delivery system (10) for a combustion engine, such as a gas turbine engine. A valve pack (72) is integrated into a fuel metering unit (12) and provides shutoff and overspeed protection, including verification of the operational integrity of the shutoff and overspeed protection components. A bypass directional control valve (150) is integrated into one embodiment of the fuel metering unit (12) and provides directional control of a bypass flow from an upstream side of a fuel metering valve (20) based upon the position of a metering valve spool (44) in the metering valve (20).
79 Citations
6 Claims
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1. A valve pack for use in a fuel delivery system for providing a desired fuel flow to an engine, the fuel deliver system including a metering valve having a metering state where the metering valve provides a metered fuel flow to the engine in response to a pressure differential between a reference pressure chamber and a modulated pressure chamber of the valve and a shutoff state wherein the metering valve blocks fuel flow to the engine in response to a pressure differential between the reference and modulated pressure chambers;
- the valve pack comprising;
a fuel inlet port to receive a metered fuel flow from the fuel metering valve;
a fuel outlet port to selectively receive the metered fuel flow from the fuel inlet port to direct the metered fuel flow to the engine;
an actuation pressure inlet port selectively connected to a drain to transfer an actuation fuel flow to the drain;
a reference pressure inlet port to receive fuel flow at a reference pressure;
a reference pressure outlet port to selectively receive the fuel flow at the reference pressure form the reference pressure inlet port to transfer the fuel flow to a modulated pressure chamber of the fuel metering valve;
an overspeed activation port; and
a shutoff activation port;
the valve pack having an overspeed state in response to the overspeed activation port being placed in fluid communication with a drain, a shutoff state in response to the shutoff activation port being placed in fluid communication with a drain and flow from the overspeed activation port to the drain being blocked, and a run state with flow from both of the overspeed and shutoff activation ports to the drain being blocked;
with the valve pack in the overspeed state, the reference pressure inlet port is connected to the reference pressure outlet port to direct fuel flow at the reference pressure from the reference pressure inlet port to the modulated pressure chamber of the fuel metering valve, the actuation pressure inlet port is opened to receive a fuel flow, and flow from the fuel inlet port to the fuel outlet port is blocked to shutoff the metered fuel flow to the engine;
with the valve pack in the shutoff state, the actuation pressure inlet port is opened to receive a fuel flow, fuel flow from the reference pressure inlet port to the reference pressure outlet port is blocked, and fuel flow from the fuel inlet port to the fuel outlet port is blocked to shutoff the metered fuel flow to the engine;
with the valve pack in the run state, the fuel inlet port is connected to the fuel outlet port to direct the metered fuel flow from the fuel inlet port to the engine, fuel flow from the reference pressure inlet port to the reference pressure outlet port is blocked, and the actuation pressure inlet port is closed;
a first valve spool positioned in the valve pack to block fuel flow from the fuel inlet port to the fuel outlet port with the valve pack in the overspeed state and with the valve pack in the shutoff state; and
a second valve spool positioned in the valve pack to block fuel flow through the actuation pressure inlet port with the valve pack in the run state. - View Dependent Claims (2, 3)
- the valve pack comprising;
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4. A fuel delivery system for providing a desired fuel flow to an engine from a pump, the system comprising:
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a metering valve including a metering valve spool, a first pressure chamber at one end of the valve spool, a modulated pressure chamber at the other end of the valve spool to receive a modulated pressure, the valve spool having a metering position where the valve provides a metered fuel flow to the engine in response to a pressure differential between the reference and modulated pressure chambers and a closed position wherein the metering valve blocks fuel flow to the engine in response to a pressure differential between the reference and modulated pressure chambers a servo valve including a modulated output port connected to the modulated pressure chamber to supply the modulated pressure thereto;
a shutoff valve including a fuel inlet port connected to the metering valve to receive the metered fuel flow therefrom, a fuel outlet port selectively connected to the fuel inlet port to direct the metered fuel flow to the engine, a first reference pressure inlet port to receive a fuel flow at a reference pressure, a first reference pressure outlet port, an actuation port to receive a fuel flow at an actuation pressure, and a shutoff valve spool movable between open and closed positions in response to a pressure differential between the actuation port and the fuel inlet port, a shutoff activation valve including an actuation pressure inlet port to receive a fuel flow at the actuation pressure, an actuation pressure outlet port connected to the actuation pressure port of the shutoff valve to direct the fuel flow at the actuation pressure thereto, a second reference pressure inlet port connected to the reference pressure outlet port to receive the fuel flow at the reference pressure therefrom, a second reference pressure outlet port connected to the modulated pressure chamber of the metering valve to deliver the fuel flow at the reference pressure thereto, a third port, a fourth port, and a shutoff activation valve spool movable between first, second, and third positions in response to a pressure differential between the actuation pressure inlet port and the third port, the third and fourth ports being in fluid communication and flow between the actuation pressure inlet and outlet ports and between the second reference pressure inlet and outlet ports being blocked with the shutoff activation valve spool in the first position, flow between the second reference pressure inlet and outlet ports being blocked, fuel flow from the third port to the fourth port being modulated, and the actuation pressure inlet port being in fluid communication with the actuation pressure outlet port to transfer the fuel flow at the actuation pressure thereto with the shutoff activation valve spool in the second position, the second reference pressure inlet port being in fluid communication with the second reference pressure outlet port to transfer a fuel flow thereto, the actuation pressure inlet port being in fluid communication with the actuation pressure outlet port to transfer a fuel flow thereto, and flow between the third and fourth ports being blocked with the valve in the third position;
an overspeed solenoid valve having an open state wherein the third port is connected to a drain to transfer a fuel flow thereto, and a closed state wherein fuel flow between the third port and the drain is blocked;
a shutoff solenoid valve having a open state wherein the fourth port is connected to the drain to transfer a fuel flow thereto, and a second state wherein fuel flow between the fourth port and the drain is blocked. - View Dependent Claims (5, 6)
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Specification