Fuel Filling Assembly Venting Layout for Lower Vapor Emissions
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Solution Overview
Problem
Existing fuel system filling assemblies in vehicles emit fuel vapors into the atmosphere during filling due to air intake from the atmosphere, which can overload the fuel vapor filter, and mechanical seals complicate durability and require specific system architecture.
Innovation Solution
A method for structural optimization of the fuel system filling assembly involves measuring gas flows, configuring an air inlet in the tubing to manage air suction, and optimizing vent line passages to minimize fuel vapor emissions, using deformable bodies or through-holes to control air flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a mechanical seal is introduced within the top of the tubing to prevent air intake, then fuel vapor emissions are reduced, but the durability of the mechanical seal becomes problematic and the system architecture becomes more complex
Solution Approach 1:
The invention removes the mechanical seal from the system entirely. Instead of trying to seal the top of the tubing, the patent uses a vent line with controlled resistance that allows air to be drawn in through the fuel tank, thereby eliminating the mechanical seal and its associated durability problems while still preventing fuel vapor emissions
Solution Approach 2:
The invention introduces a vent line as an intermediary element between the fuel tank and the top of the tubing. This vent line with specific resistance values acts as a mediator that controls air flow into the system, allowing air intake to occur through the fuel tank rather than directly at the top of the tubing, thus eliminating the need for mechanical sealing
2Productivity
If the vent line is sized to enable proper filling with a mechanical seal, then filling performance is improved, but the system complexity and durability issues increase
Solution Approach 1:
The invention eliminates the mechanical seal component entirely, simplifying the system architecture. The vent line is designed with specific resistance characteristics that enable proper filling performance without requiring any sealing mechanism, thus removing the complexity associated with mechanical seal integration and sizing
Solution Approach 2:
The invention changes the approach from mechanical sealing to fluid dynamic control by specifying vent line resistance parameters. The vent line is designed with resistance values between 0.5-2 kPa/(L/min) that naturally control air flow during filling, replacing mechanical parameters with fluid dynamic parameters for system control
3Object-generated harmful factors
If air intake from the atmosphere is increased to prevent fuel vapor emissions, then the fuel vapor load on the canister is reduced, but excessive air intake occurs at high fuel flow rates
Solution Approach 1:
The invention changes the air intake path and controls it through vent line resistance parameters. By designing the vent line with specific resistance values (0.5-2 kPa/(L/min)), the system automatically regulates air flow based on filling conditions, preventing both excessive air intake at high flow rates and insufficient air intake at low flow rates
Solution Approach 2:
The vent line acts as an intermediary that mediates between the fuel tank and the top of the tubing, controlling air flow based on system pressure conditions. This intermediary element ensures that air is drawn in at appropriate rates depending on the fuel flow rate, automatically balancing air intake with filling conditions
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 method effectively reduces fuel vapor emissions to the atmosphere and minimizes the load on the fuel vapor filter, improving ergonomics and maintaining system integrity without complex mechanical seals.
Implementation Method 1
the flow of fuel out of the filling gun is such that it creates a negative pressure which draws air from the atmosphere
Implementation Method 2
The presence of this mechanical seal prevents air from being drawn into the top of the tubing from the atmosphere
Implementation Method 3
It contains activated carbon, which adsorbs the hydrocarbon molecules contained in fuel vapors
Data Source
AI summary
The invention relates to a method for structural optimization of a filling assembly 1 of a fuel system 2. According to the invention, such a method comprises the steps of filling the fuel system using the filling assembly 1, at a flow rate of a liquid 20, Qp; of measuring of a gas flow rate 11, Qc, at the outlet of the fuel vapor filtration device 7; of measuring a flow rate of gas heading towards the top of the tubing 12, Qr, within the second vent line 8, of calculating flow rate of gas exiting the fuel tank 13, Qd, using the relationship Qd=Qc+Qr; of determining a flow rate of air 14 entering through the top 3 of the tubing, Qa, using the relationship Qa=Qc−Qp and of configuring an air inlet 301 in the top of the tubing.