Nested Piston Valve Assembly for Linear High-Flow Anti-Ice Control
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Solution Overview
Problem
Existing aircraft anti-ice system valves struggle to balance high-mass flow rates with linear pressure regulation, with butterfly valves excelling in high flow but lacking linearity, and other types being more linear but less capable at high flows.
Innovation Solution
A dual co-axial piston configuration with overlapping pistons, where one piston is nested within the other, allowing increased stroke length without increasing overall assembly length, combined with a solenoid valve and biasing device for precise control, enabling high flow rates and linear pressure regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a butterfly valve is used, then high mass flow rate is achieved, but linear pressure regulation capability deteriorates
Solution Approach 1:
The regulating piston is nested inside the first piston, creating a compact dual-piston arrangement where the regulating piston operates within the bore of the first piston. This nesting allows both pistons to function simultaneously without requiring separate spatial volumes, enabling high mass flow through the first piston while the nested regulating piston provides precise linear pressure control.
Solution Approach 2:
The valve function is segmented into two independent piston mechanisms: the first piston handles shut-off and high flow regulation, while the nested regulating piston handles precise pressure modulation. This segmentation allows each piston to be optimized for its specific function, with the first piston providing high capacity and the regulating piston providing linearity.
2Measurement precision
If a pressure-regulating valve with long stroke is used, then linear regulation is improved, but device length increases
Solution Approach 1:
The regulating piston is positioned inside the first piston, allowing the regulating piston's stroke to occur within the spatial envelope of the first piston. This nesting eliminates the need for sequential arrangement, enabling long stroke lengths for both pistons without increasing the overall valve assembly length.
Solution Approach 2:
Instead of arranging pistons sequentially along the flow direction (one dimension), the invention places the regulating piston radially inside the first piston (another dimension). This dimensional reorganization allows both pistons to have extended strokes without increasing the axial length of the valve assembly.
3Adaptability or versatility
If two separate valves are used to achieve both high flow and linear regulation, then functional capability is improved, but device complexity increases
Solution Approach 1:
Two separate valve functions (high flow control and linear pressure regulation) are merged into a single integrated valve assembly with nested pistons. The first piston and regulating piston operate simultaneously within the same valve body, sharing common sealing surfaces and fluid passages, thereby achieving dual functionality without the complexity of two separate valves.
Solution Approach 2:
The nested piston arrangement enables a single valve assembly to perform multiple functions: the first piston provides shut-off and high flow capability, while the nested regulating piston provides linear pressure regulation. This multi-functionality is achieved within one integrated structure rather than requiring separate specialized valves.
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 achieves enhanced airflow and pressure regulation capabilities, allowing for higher mass flow rates and linear proportional output pressure without increasing the valve's physical dimensions, addressing the limitations of existing valve designs.
Implementation Method 1
the regulating piston is moved depending on a pressure difference between downstream pressure and pressure in a regulating chamber
Implementation Method 2
The valve assembly may comprise a solenoid valve operable to pressurise the first chamber and thereby close the valve inlet using the first piston
Data Source
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AI summary
A valve assembly 100 for an anti-ice system of an aircraft. The valve assembly 100 comprises: a valve body 110; a first piston 120; and a regulating piston 140. The valve body 110 defines a valve inlet 112, a valve outlet 114, a fluid passage between the valve inlet 112 and the valve outlet 114, and a core portion 116 defining a first chamber 112 by cooperation with the first piston 120 and a regulating chamber 142 by cooperation with the regulating piston 140. The first piston 120 is moveable between a first position and a second position, and the regulating piston 140 is movable between a first position and a second position. The first piston 120 overlaps the regulating piston 140 when the first piston 120 is its first position and the regulating piston 140 is in its second position.