Laser Ignition Window Cleaning via Inert Gas Atmosphere

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Solution Overview

Problem

The main challenge in implementing laser ignition for internal combustion engines is maintaining the optical properties of the combustion chamber window over extended engine operation, as high thermo-chemical loads and solid residue deposits lead to clouding, reducing plasma spark energy and potentially causing its absence, necessitating high laser power for burn-off which increases costs and wear.

Innovation Solution

A device with a separate fluid supply system directs a fluid, such as inert gas, onto the combustion chamber window and between the window and the focal point, creating an antechamber that prevents deposits and allows the laser to operate at lower power, extending the device's service life by maintaining a clean window surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high laser power is used to burn-off deposits on the combustion chamber window, then the optical properties are maintained, but the costs and wear increase significantly

Engineering Contradiction:
Improveoptical properties of combustion chamber windowVSAvoidcosts and wear
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by introducing an inert gas atmosphere into the combustion chamber before combustion occurs. This preventive measure protects the combustion chamber window from deposit formation in the first place, eliminating the need for subsequent burn-off operations and reducing both costs and wear while maintaining optical properties throughout the engine's operational life

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements an inert atmosphere by filling the combustion chamber with an inert gas (such as nitrogen or argon) before introducing the fuel mixture. This inert environment prevents oxidative reactions that would otherwise form deposits on the combustion chamber window, thereby maintaining its optical transparency without requiring high-power laser cleaning

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Productivity

If the laser beam is focused deep within the combustion chamber, then optimal ignition conditions are achieved, but deposits on the window scatter and absorb the beam

Engineering Contradiction:
Improveignition efficiencyVSAvoidlaser beam energy
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

By maintaining an inert gas atmosphere in the combustion chamber, the patent prevents the formation of absorbing and scattering deposits on the combustion chamber window. This ensures that the laser beam retains its energy and focus as it travels through the chamber, enabling effective ignition deep within the combustion space without energy loss

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

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 keeps the combustion chamber window free of deposits, reduces the need for high laser power, and increases the service life of the device by preventing interference absorption, allowing for efficient and reliable plasma spark generation without the costs associated with high laser power burn-off.

Implementation Method 1

an intense laser pulse is concentrated at a focal point within the combustion chamber. The extremely high field strength of the laser beam at this focal point ionizes the gas, subsequently heating it to plasma temperatures (several thousand Kelvin)

Methodology Applied
Scientific EffectLaser heating and ionization: Laser

Implementation Method 2

The extremely high field strength of the laser beam at this focal point ionizes the gas, subsequently heating it to plasma temperatures

Methodology Applied
Scientific EffectPlasma formation: Plasma

Implementation Method 3

at least one fluid supply device separate from the inlet valve(s) with which a fluid can flow at least onto areas of the surface of the combustion chamber window or between the combustion chamber window and the focal point of the laser light

Methodology Applied
Scientific EffectFluid flow protection: Fluid Spray

Data Source

PatentEP2072803B1Device for igniting a fuel-air mixture in a combustion chamber of an internal combustion engine
Publication Date: 2020.04.22 GE JENBACHER GMBH & CO OG
  • EP2072803B1 patent drawingFigure 1
  • EP2072803B1 patent drawingFigure 2
  • EP2072803B1 patent drawingFigure 3

AI summary

Device (10) for igniting a fuel/air mixture in the combustion chamber (11) of an internal combustion engine, wherein the combustion chamber has at least one inlet valve (34) and at least one outlet valve (35), wherein a laser light generation device (1) for emitting laser light and a combustion chamber window (3) for coupling the laser light into a combustion chamber (11) of the internal combustion engine are further provided, wherein at least one fluid supply device (6) separate from the inlet valve(s) (34) is provided, with which a fluid can flow at least onto areas of the surface of the combustion chamber window (3) or between the combustion chamber window (3) and the focal point (4) of the laser light.