Two-Valve Fuel Tank Venting System for Refueling Control
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Solution Overview
Problem
Existing vehicle fuel systems face issues with combining tank pressure control and refueling, leading to potential corking of fuel tank valves, excessive hydrocarbon release, and air-fuel ratio degradation due to the use of a single fuel tank isolation valve.
Innovation Solution
Implementing a system with a tank pressure control valve and a refueling valve in parallel conduits between the fuel tank and the fuel vapor canister, allowing for controlled fuel tank depressurization during refueling without exposing vent valves to rapid pressure changes, thereby preventing valve closure and ensuring proper refueling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single fuel tank isolation valve is used to control both tank pressure and refueling, then device complexity is reduced, but reliability deteriorates due to potential valve corking and improper operation
Solution Approach 1:
The patent divides the single valve function into two separate valves: a tank pressure control valve and a refueling valve. This segmentation allows each valve to perform its specific function independently, preventing the corking issue that occurs when a single valve must handle both pressure control and refueling operations, thereby improving reliability while maintaining acceptable system complexity.
2Stress or pressure
If the fuel tank isolation valve is opened completely during refueling to equalize pressure, then pressure control is improved, but harmful factors increase due to valve corking and excessive hydrocarbon release
Solution Approach 1:
By separating pressure control functions from refueling functions into different valves, the system can control pressure gradual equalization through the pressure control valve without completely opening the refueling valve, thus preventing hydrocarbon release and valve corking while still achieving proper pressure management.
Solution Approach 2:
The tank pressure control valve acts as an intermediary that gradually equalizes pressure between the fuel tank and atmosphere during refueling, allowing the refueling valve to remain partially closed and avoid direct exposure to rapid pressure changes that cause corking and hydrocarbon release.
3Device complexity
If a single valve controls both purging and refueling operations, then device complexity is reduced, but productivity deteriorates due to delays and imprecision in control
Solution Approach 1:
The patent assigns different operational functions to separate valves: the tank pressure control valve handles purging operations with precise control, while the refueling valve handles refueling. This segmentation eliminates the delays and imprecision that occur when a single valve must switch between different operational modes, improving overall system productivity.
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 control over fuel tank venting and depressurization, reducing system complexity and cost while preventing valve corking and maintaining an optimal air-fuel ratio during refueling.
Implementation Method 1
vaporized hydrocarbons (HCs) from a fuel tank may be stored in a fuel vapor canister packed with an adsorbent which adsorbs and stores the vapors
Data Source
AI summary
A system for a vehicle, comprising: a tank pressure control valve coupled in a first conduit between a fuel tank and a fuel vapor canister; a refueling valve coupled in a second, different, conduit between the fuel tank and the fuel vapor canister, the second conduit in parallel to the first conduit. In this way, two smaller, less complex valves may be utilized to control fuel tank vapor purging and fuel tank depressurization during refueling. This in turn may lower system cost and increase system functionality.