Multi-Step Fuel Pressurizing Valve Layout for Low-Pressure Actuation
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Solution Overview
Problem
Conventional fuel systems for turbine engines require high minimum pressure differentials for actuator flow, making ground maintenance or low-speed actuation difficult, and necessitate larger pump sizes due to significant leakage proportional to pressure differential.
Innovation Solution
The fuel system eliminates the inlet pressurizing valve and directs high-pressure fuel directly to the bypass valve, controlling actuators with a lower pressure differential through a bypass valve and discharge pressurizing valve configuration, allowing actuation at reduced pressures and minimizing pump size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an inlet pressurizing valve is used to set high system pressure, then fuel flow to actuators is controlled, but the pressure differential required is too high (350 psid) to allow ground maintenance or low-speed actuation
Solution Approach 1:
The patent segments the pressure control function into two distinct valves: a discharge pressurizing valve (DPV) that maintains high system pressure (350 psid) for normal operation, and an actuator regulating valve (ARV) that controls pressure to actuators at a lower differential (90 psid). This segmentation allows the system to maintain reliable actuator control while enabling ground maintenance operations that were previously impossible due to excessive pressure differential requirements.
2Power
If high pressure differential (350 psid) is maintained for actuator flow, then system pressure is sufficient for engine operation, but pump size must be larger due to leakage proportional to pressure differential
Solution Approach 1:
The patent applies local quality by creating different pressure conditions in different parts of the system. The DPV maintains high pressure (350 psid) in the fuel manifold for engine operation, while the ARV creates a localized low-pressure zone (90 psid differential) at the actuator. This allows the pump to be sized for the localized actuator requirement rather than the entire system, reducing pump size and weight while maintaining sufficient power for engine operation.
3Weight of stationary object
If inlet pressurizing valve is eliminated and high-pressure fuel is directed directly to bypass valve, then pump size can be minimized, but pressure control for actuators becomes more complex
Solution Approach 1:
The patent extracts the inlet pressurizing valve (IPV) from the system, eliminating the component that created the excessive pressure differential problem. By removing the IPV, the system can operate with a smaller pump. The pressure control function previously performed by the IPV is redistributed to the DPV and ARV, which work together to provide both high system pressure and low differential actuator control without requiring the intermediate IPV stage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables low-speed actuation and reduced sensitivity to downstream pressure variations, achieving actuator control with a pressure differential as low as 90 psid, thereby facilitating ground maintenance and optimizing pump size.
Implementation Method 1
A position of the bypass valve member to produce fuel flow through the bypass valve outlet at the second pressure is controlled at a first end by the third pressure and at a second end by the fourth pressure and a biasing element
Implementation Method 2
The flow sense valve member is movable between a closed position and an open position in response to a pressure differential between the flow sense valve inlet and the flow sense valve outlet
Data Source
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AI summary
Embodiments of a fuel system are disclosed. The fuel system includes a bypass valve (BPV), a fuel metering valve (FMV), a flow sense valve (FSV), and an actuator regulating valve (ARV). The BPV includes a BPV valve member that regulates fuel flow from a BPV inlet to a BPV outlet. The position of the BPV valve member is controlled by pressures at an inlet and an outlet of the FMV. The FSV includes an FSV valve member that regulates fuel flow from an FSV inlet to an FSV outlet. The ARV includes an ARV inlet that is in fluid communication with the FSV outlet, and fuel flow through an ARV outlet regulates downstream actuators. The position of the FSV valve member to produce fuel flow through the FSV outlet to the ARV inlet is controlled at least in part by a pressure at the BPV outlet.