Saddle Fuel Tank Electronic Venting Control
Solution Overview
Problem
Saddle fuel tanks with independent lobes face challenges in proper venting and accurately determining the total fuel volume, leading to incorrect full fuel condition assumptions due to geometry interactions with existing shut-off valve configurations.
Innovation Solution
A fuel tank system with a saddle design incorporating a control module, solenoids, vent lines, and a liquid trap with a mechanical vapor discriminating valve, allowing independent venting of each lobe and ensuring accurate determination of the total fuel volume by closing vents upon reaching a full fuel condition, thus preventing liquid interference with vent ports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a saddle fuel tank with independent lobes is used, then the fuel tank can accommodate different fuel volumes in each lobe, but the geometry causes incorrect full fuel condition detection
Solution Approach 1:
The fuel tank is divided into independent lobes (first lobe and second lobe) that can be filled to different levels, allowing versatile fuel storage. Each lobe has its own vent line and solenoid control, enabling independent management of fuel levels in each segment while maintaining accurate overall fuel volume detection.
2Reliability
If existing shut-off valve configurations are used in saddle tanks, then the tank can vent fuel vapor, but the geometry causes liquid fuel to interfere with vent ports leading to incorrect full fuel assumptions
Solution Approach 1:
The vent ports are positioned in the upper portion of each lobe, elevated above the recessed central portion, creating a vertical dimension that prevents liquid fuel from reaching the vent ports. This dimensional arrangement ensures that venting occurs only for fuel vapor while liquid fuel remains below the vent port level, eliminating incorrect full fuel assumptions.
3Device complexity
If vent ports are positioned at existing locations, then the tank structure is simple, but liquid fuel can reach vent ports causing inadequate venting and fuel fill issues
Solution Approach 1:
The vent ports are pre-positioned in the upper portion of each lobe above the recessed central portion before fuel filling occurs. This preliminary positioning ensures that as fuel is added to the tank, the liquid level rises but remains below the vent port level due to the saddle geometry, preventing liquid interference with venting function from the outset.
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 system ensures accurate identification of a 100% full fuel condition independently of fuel height in each lobe, preventing inadequate venting and fuel fill issues by positioning vent ports above the liquid level and using solenoids or a cam-driven mechanism to control venting.
Implementation Method 1
The first solenoid is configured to open and close the first vent port
Implementation Method 2
The liquid trap can include a venturi jet that drains liquid by way of a vacuum out of the liquid trap
Implementation Method 3
The LVD valve can have a membrane filer configured to prevent passage of liquid through the membrane and allow passage of at least one of air and fuel vapor through the membrane
Data Source
AI summary
A fuel tank system constructed in accordance to one example of the present disclosure includes a saddle fuel tank, a control module, a first and second solenoid, and a first and second vent line. The saddle fuel tank can have a first lobe and a second lobe. The first vent line can have a first vent port located in the first lobe of the saddle fuel tank. The first solenoid is configured to open and close the first vent port. The second vent line can have a second vent port located in the second lobe of the saddle fuel tank. The second solenoid is configured to open and close the second vent port. The control module sends a signal to the first and second solenoids to close the first and second vents upon reaching a full fuel condition.