Flow Sensing Shutoff Valve for Fuel Metering
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Solution Overview
Problem
Traditional open loop variable flow source systems lack sufficient flow rate accuracy, necessitating a closed loop system with additional components like fuel metering valves and pressure regulation systems to achieve precise control of pressurized fuel flow to engine combustion chambers.
Innovation Solution
A flow sensing valve with a valve housing, inlet and outlet ports, and flow sensing ports, coupled with a position sensor and controller, allows for precise control of the metered flow rate by determining the valve position and operating the variable flow source based on the valve open port area, reducing the need for separate pressure regulation and metering valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a closed loop system with separate fuel metering valve and pressure regulation system is used, then flow rate accuracy is improved, but device complexity increases
Solution Approach 1:
The patent combines the fuel metering valve and pressure regulation system into a single integrated flow sensing valve assembly. The valve housing contains both the metering function (through the valve member controlling flow to combustion chambers) and the pressure regulation function (through the spring-loaded diaphragm mechanism that maintains constant differential pressure across the valve), eliminating the need for separate components while maintaining measurement precision.
Solution Approach 2:
The flow sensing valve performs multiple functions simultaneously: it meters fuel flow to combustion chambers, regulates differential pressure across the valve, provides flow sensing feedback, and enables shutoff operations. This multi-functional design replaces what would traditionally require separate dedicated components for each function, reducing overall system complexity while maintaining accurate flow rate control.
2Measurement precision
If separate pressure regulation system and shutoff valve are added, then flow control precision is improved, but system reliability decreases
Solution Approach 1:
The shutoff function is integrated into the valve member mechanism itself. The valve member can be positioned to completely block fuel flow to all combustion chambers, providing a reliable shutoff function without requiring a separate shutoff valve. This integration reduces the number of moving parts and potential failure points while maintaining precise flow control capability.
3Measurement precision
If multiple separate components are used, then flow metering accuracy is improved, but system cost increases
Solution Approach 1:
The patent integrates multiple functions (fuel metering, pressure regulation, flow sensing, and shutoff) into a single valve housing assembly with a unified valve member mechanism. This consolidation eliminates the need for multiple separate components that would be required in a traditional system, reducing manufacturing costs, assembly complexity, and maintenance requirements while maintaining accurate flow metering capability.
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 solution enhances flow rate accuracy and system reliability by directly controlling the metered flow rate through closed loop feedback, reducing system complexity and cost while maintaining a nearly constant differential pressure across the valve.
Implementation Method 1
the flow sensor detects whether water is flowing through the valve body
Implementation Method 2
a solenoid actuator that moves a valve stem between an open position and a closed position in response to a signal from the microcontroller
Implementation Method 3
O-rings positioned around the valve stem and the plunger that move with the valve stem and plunger, respectively, to help seal water
Data Source
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AI summary
A flow sensing valve includes a valve housing having an inlet port, an outlet port, and a plurality of flow sensing ports. A valve member, located within the valve housing, is configured to move between an open position and a closed position. The valve member allows fuel flow between the inlet port and outlet port in the open position, and blocks fuel flow between the inlet port and the outlet port in the closed position. A position sensor, operably coupled to the valve member, is configured to determine a valve position of the flow sensing valve. The valve position is indicative of a valve open port area. A metered flow rate of pressurized fuel through the flow sensing valve in a upstream manifold is proportional to the valve open port area because the flow sensing valve maintains a nearly constant differential pressure across the inlet and outlet ports.