Fuel Recirculation Ejector Valve Control via Pressure Monitoring

Solution Overview

Problem

Existing vehicle fuel systems face challenges in reducing air entrainment and further vaporization of fuel during refueling, leading to inefficiencies and potential increases in emissions.

Innovation Solution

A fuel system with a recirculation line connected to the fuel fill inlet and fuel tank, featuring an ejector and a valve in the drain line, where a pressure sensor monitors the pressure between the ejector and valve to control the valve's position, ensuring the valve remains closed during refueling to prevent vapor flow through the drain line and maintain vapor recirculation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a recirculation line is provided without active monitoring, then the system structure is simple, but the valve position cannot be reliably determined leading to potential vapor loss

Engineering Contradiction:

Improvevalve position determination reliabilityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical position sensing mechanisms with a pressure-based detection system. A pressure sensor monitors pressure changes in the drain line to indirectly determine valve position, converting a mechanical positioning problem into a pressure measurement problem that is more reliable and easier to implement

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces pressure as an intermediary parameter to infer valve position. Rather than directly sensing valve position, the system uses pressure changes in the drain line as a mediator to indirectly determine whether the valve is open or closed, providing reliable information without complex direct sensing

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the check valve is not properly controlled, then the system operation is simple, but vapor is lost through the drain line reducing fuel efficiency

Engineering Contradiction:

Improvefueling efficiencyVSAvoidfuel vapor loss

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent implements a feedback control system where the controller continuously monitors pressure sensor readings and adjusts the check valve position accordingly. The pressure information feeds back to the controller, which then actuates the valve to maintain proper recirculation flow and prevent vapor loss

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The recirculation system is designed to be self-regulating through the feedback mechanism. The pressure sensor automatically detects conditions and triggers valve adjustment without external intervention, allowing the system to self-correct and maintain optimal operation throughout the fueling process

Inventive Principle:

Principle #25Self-service

3Measurement precision

If pressure monitoring is implemented in the drain line, then valve position can be accurately detected, but the device complexity increases

Engineering Contradiction:

Improvevalve position measurement precisionVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical position sensing mechanisms with a pressure-based detection system. A pressure sensor monitors pressure changes in the drain line to indirectly determine valve position, converting a mechanical positioning problem into a pressure measurement problem that is more reliable and easier to implement

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces pressure as an intermediary parameter to infer valve position. Rather than directly sensing valve position, the system uses pressure changes in the drain line as a mediator to indirectly determine whether the valve is open or closed, providing reliable information without complex direct sensing

Inventive Principle:

Principle #24Intermediary (Mediator)

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 effectively reduces air entrainment and vaporization within the fuel tank, enhancing fuel efficiency and minimizing emissions by maintaining vapor flow through the recirculation line and preventing liquid fuel from entering the evaporative emissions system during refueling.

Implementation Method 1

A vacuum is drawn on a check valve via the ejector thereby maintaining the check valve in a closed position to prevent fluid flow through a drain line

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

A pressure sensor is positioned to measure a pressure in the drain line between the ejector and the check valve

Methodology Applied

Scientific EffectPressure measurement:

Data Source

PatentUS11518238B1System and method for controlling flow in a fuel recirculation line

Publication Date: 2022.12.06 FORD GLOBAL TECH LLC

AI summary

A fuel system, a method of fueling a vehicle, and a vehicle are provided. The fuel system has a recirculation line connecting a fuel tank to a fuel fill inlet. An ejector is positioned within the recirculation line, and a valve is positioned within a drain line fluidly connecting the ejector to the fuel tank. A pressure sensor is positioned to measure a pressure associated with the drain line between the ejector and the valve. A controller is in communication with the pressure sensor, and the controller configured to, in response to initiation of a refueling event, determine a state of the valve based on the pressure.