Gaseous Fuel Pressure Control via Engine Injection

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Solution Overview

Problem

Existing fuel systems for combustion engines vent excess gaseous fuel back to a tank when pressure needs to be decreased, requiring energy to re-pressurize it for reuse, which is inefficient.

Innovation Solution

A method and system that reduces gaseous fuel pressure in an accumulator by using fuel injections from the accumulator into the combustion engine's combustion chambers, rather than venting fuel to a tank, while closing or reducing the inlet valve, thereby eliminating the need for venting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If gaseous fuel is vented back to a tank when accumulator pressure needs to be decreased, then pressure control is achieved, but energy is consumed to re-pressurize the gas for reuse

Engineering Contradiction:

Improveaccumulator pressureVSAvoidenergy consumption

Core Design Contradiction:

Stress or pressureVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful effect of excess pressure in the accumulator into a beneficial effect by using the excess fuel to perform useful work. Instead of venting the fuel to a tank where it would need to be re-pressurized, the system uses combustion-contributing fuel injections to consume the excess fuel productively, thereby reducing pressure while generating useful torque in the process.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system uses its own combustion process to regulate accumulator pressure. By controlling the fuel injection quantity and timing to contribute to combustion, the engine's own operation becomes the mechanism for pressure control, eliminating the need for separate venting and re-pressurization systems.

Inventive Principle:

Principle #25Self-service

2Loss of substance

If gaseous fuel is vented to a tank for reuse, then fuel is not wasted, but the system complexity increases due to additional components and processes

Engineering Contradiction:

Improvefuel wasteVSAvoidsystem complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The fuel injection system serves multiple functions: it delivers fuel for combustion and simultaneously acts as a pressure control mechanism for the accumulator. By making the injection system multi-functional, the patent eliminates the need for separate venting valves and tank management systems, thereby reducing overall system complexity while preventing fuel waste through productive utilization.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Use of energy by moving object

If combustion-contributing fuel injections are used to reduce accumulator pressure, then energy efficiency improves, but excessive torque may be generated

Engineering Contradiction:

Improveenergy efficiencyVSAvoidtorque

Core Design Contradiction:

Use of energy by moving objectVSForce

Solution Approach 1:

The system monitors accumulator pressure and engine torque in real-time, using this feedback information to dynamically adjust the fuel injection quantity and timing. When pressure reduction is needed, the control unit calculates the appropriate injection amount that achieves pressure control while minimizing excessive torque generation, thereby balancing energy efficiency with smooth engine operation.

Inventive Principle:

Principle #23Feedback

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 approach reduces energy consumption by avoiding the need to vent and re-pressurize gas, maintaining efficient engine operation and minimizing excessive torque through controlled fuel injections, which can be further mitigated by braking or energy recuperation.

Implementation Method 1

an inlet valve, which inlet valve is adapted to regulate input of gaseous fuel to the accumulator

Methodology Applied

Scientific EffectValve regulation: Valve

Implementation Method 2

at least one injector; introducing less gaseous fuel into the accumulator than the determined nominal amount by reducing or closing an inlet valve

Methodology Applied

Scientific EffectFuel injection: Injector

Implementation Method 3

performing at least one injection of gaseous fuel coming from the accumulator into at least one combustion chamber of the combustion engine by at least one injector of the fuel system, which at least one injection contributes to combustion in the combustion engine

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS11560858B2Method for controlling gaseous fuel pressure

Publication Date: 2023.01.24 VOLVO TRUCK CORP

AI summary

The invention relates to a method for controlling gaseous fuel pressure in an accumulator (12) of a fuel system (10) for a combustion engine (102) of a vehicle (100), wherein the method comprises the steps of: determining a nominal amount of gaseous fuel to be introduced into the accumulator; introducing less gaseous fuel into the accumulator than the determined nominal amount by reducing or closing an inlet valve (24), which inlet valve is adapted to regulate input of gaseous fuel to the accumulator; and while the inlet valve is reduced or closed, performing at least one injection of gaseous fuel coming from the accumulator into at least one combustion chamber (104a-f) of the combustion engine by at least one injector (14a-f) of the fuel system, which at least one injection contributes to combustion in the combustion engine, thereby reducing pressure in the accumulator. The invention also relates to a corresponding fuel system (10).