Fuel Return Shutoff Valve Pressure Deflector Against Premature Closure

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional ecology fuel return system shut off valves are prone to premature closure due to increased pressure drop, leading to air leakage and potential cavitation in the fuel system, which can result in reduced thrust power and fuel pump damage.

Innovation Solution

A shutoff valve design featuring a pressure deflector and poppet valve member with a disk body and guide structure, which prevents fluid flow from biasing the valve towards closure, ensuring stable operation by maintaining the valve open until the fuel manifold is fully drained.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional float-operated shutoff valve is used in the ecology fuel return system, then the valve can close the tank outlet based on fluid level, but the pressure drop across the valve during fuel flow can overcome the float's buoyancy force and cause premature valve closure

Engineering Contradiction:

Improvevalve operation reliabilityVSAvoidfuel drainage completeness

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent extracts the pressure deflector as a separate functional element from the traditional float valve assembly. This pressure deflector is specifically designed to counteract the harmful pressure drop effect, allowing the float mechanism to operate reliably without being overwhelmed by flow-induced pressure changes.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The pressure deflector acts as a counterbalancing element that provides an opposing force to the pressure drop across the valve. By positioning the deflector to receive fluid flow and generate a counteracting force, it compensates for the buoyancy force deficiency during high-flow conditions, preventing premature closure.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

2Object-affected harmful factors

If the valve closes prematurely due to pressure drop, then air leakage into the fuel system is prevented, but fuel pockets remain in the manifold and nozzles causing coking and uneven fuel supply

Engineering Contradiction:

Improveair leakage preventionVSAvoidfuel supply uniformity

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The pressure deflector serves as an intermediary element between the fluid flow and the valve closing mechanism. It mediates the interaction by converting the harmful pressure drop into a useful counterbalancing force, ensuring the valve remains open long enough to complete fuel drainage while still preventing air leakage when appropriate.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of operation

If the float has low mass to maintain sensitivity, then the valve can respond to small fluid level changes, but the float cannot overcome increased pressure drop during high flow rates

Engineering Contradiction:

Improvevalve response sensitivityVSAvoidfloat buoyancy force

Core Design Contradiction:

Ease of operationVSForce

Solution Approach 1:

The patent segments the valve control function into two independent components: the float mechanism for level sensing and the pressure deflector for flow compensation. This segmentation allows the float to remain lightweight and sensitive while the pressure deflector handles the force balance during high-flow conditions.

Inventive Principle:

Principle #1Segmentation

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

The solution prevents premature valve closure, reducing air leakage and cavitation, thereby ensuring consistent fuel supply and preventing fuel pump degradation, enhancing engine performance and reliability.

Implementation Method 1

The valve member can include a pressure deflector configured to prevent fluid flow from biasing the valve member toward the closed position

Methodology Applied

Scientific EffectPressure deflection: Pressure Drop

Implementation Method 2

The float of the shutoff valve is sensitive to the influence of external loads as the valve operates with low or no force margin to keep it closed

Methodology Applied

Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 3

The flow through the inlet shutoff valve creates a pressure drop across that valve that acts to drive traditional valves shut against the weight of the float

Methodology Applied

Scientific EffectPressure drop: Pressure Drop

Implementation Method 4

fuel pump damage (due to cavitation in the two-phase flow of gaseous air and liquid fuel)

Methodology Applied

Scientific EffectCavitation: Cavitation

Data Source

PatentUS11879394B2Shut off valves and components thereof for ecology fuel return systems

Publication Date: 2024.01.23 HAMILTON SUNDSTRAND CORP

AI summary

In at least one aspect of this disclosure, a shut off valve for an ecology fuel return system can include an inlet for receiving a fluid, an outlet for effusing the fluid, and a valve member configured to move between an open position such that the valve member allows fluid to effuse from the outlet and a closed position such that the valve member prevents fluid from effusing from the outlet. The valve member can include a pressure deflector configured to prevent fluid flow from biasing the valve member toward the closed position.