Passive Inline Bleed Valve Using Differential Pressure Control

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Solution Overview

Problem

Conventional bleed valves in gas turbine engines require active control mechanisms, which add complexity, mass, and size, and are not optimally efficient in managing fluid flow during engine starting and steady-state operations.

Innovation Solution

A passively controlled bleed valve design featuring a housing with a duct, a guide tube, and a piston with orifices, where the piston moves between open and closed positions based on differential pressure, eliminating the need for solenoids or pneumatic controllers by using a biasing member and sealing rings to manage fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If active control mechanisms (solenoids or pneumatic controllers) are used to operate bleed valves, then the valve can be precisely controlled, but the complexity, mass, and size of the system increase

Engineering Contradiction:
Improvevalve control precisionVSAvoidcontrol mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bleed valve operates automatically using the pressure differential across the compressor itself. The control mechanism uses the system's own operating conditions (pressure difference between inlet and outlet) to actuate the valve, eliminating the need for external solenoids or pneumatic controllers. This self-service approach reduces device complexity while maintaining reliable control.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces active mechanical/electrical control systems (solenoids, pneumatic controllers) with a passive mechanical control mechanism. The control is achieved through pressure-driven movement of the valve element, where the pressure differential directly actuates the valve without requiring external energy sources or control electronics.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If active control mechanisms are used to operate bleed valves, then precise control is achieved, but the mass and size of the valve assembly increase

Engineering Contradiction:
Improvevalve control precisionVSAvoidvalve assembly mass
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The valve utilizes the compressor's own pressure differential to actuate, eliminating the need for heavy solenoids, pneumatic actuators, and associated control electronics. This self-service mechanism significantly reduces the mass of the valve assembly while maintaining precise control through the pressure-driven design.

Inventive Principle:
Principle #25Self-service

3Reliability

If conventional active control methods are used, then the valve can be precisely actuated, but the system size and cost increase

Engineering Contradiction:
Improvevalve actuation precisionVSAvoidsystem size
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The bleed valve system uses the compressor's inherent pressure differential to control valve actuation, eliminating the need for external control systems. This self-service approach reduces system size and complexity while maintaining precise valve control through the pressure-driven mechanism.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts and eliminates the unnecessary active control components (solenoids, pneumatic controllers, associated wiring and control systems) from the valve assembly. By removing these extraneous elements and retaining only the essential pressure-driven valve mechanism, the system size and complexity are reduced while preserving functional precision.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This design reduces complexity, mass, and size by using pressure differentials to control the valve, ensuring efficient fluid management during engine starting and steady-state operations, improving reliability and potentially reducing costs.

Implementation Method 1

the piston orifice fluidly couples the inlet with the outlet in the open and closed positions to move the piston between the open position and the closed position according to differential in pressure between the inlet and the outlet of the bleed valve

Methodology Applied
Scientific EffectDifferential pressure: Pressure Gradient

Data Source

PatentEP3604744B1Passively controlled inline bleed valves
Publication Date: 2022.09.21 HAMILTON SUNDSTRAND CORP
  • EP3604744B1 patent drawingFigure 1
  • EP3604744B1 patent drawingFigure 2
  • EP3604744B1 patent drawingFigure 3A~3C

AI summary

A bleed valve (100) includes a housing (102) with an inlet (104) coupled to an outlet (106) by a duct (108). A guide tube (110) is fixed within the housing (102) between the inlet (104) and the outlet (106). A piston (112) with a piston orifice (114) is slideably supported on the guide tube (110) and movable between an open position (116) and a closed position (118). The duct (108) fluidly couples the inlet (104) to the outlet (106) in the open position (116), the duct (108) fluidly separates the inlet (104) from the outlet (106) in the closed position (118), and the piston orifice (114) fluidly couples the inlet (104) with the outlet (106) in the open position (116) and the closed position (118) to move the piston (112) between the open position (116) and the closed position (118) according to differential in pressure between the inlet (104) and the outlet (106) of the bleed valve (100). Compressors, gas turbine engines, and methods of controlling fluid flow are also described.