Turbine Ignition Procedure Using Dynamic Fuel Flow Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing ignition procedures for turbomachine combustion chambers require different types of injectors with varying flow rates, leading to increased complexity, costs, and maintenance challenges due to the need for distinct adjustments and keying mechanisms to ensure reliable ignition.

Innovation Solution

A two-phase fuel injection procedure is implemented, starting with a constant flow that rapidly increases by 20-30% if initial ignition is unsuccessful, followed by a gradual increase, allowing all injectors to operate identically and maintain a higher fuel richness without forming large flames that could impact the turbine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If injectors with higher flow rate are mounted in axial alignment of spark plugs to increase fuel richness for reliable ignition, then ignition reliability is improved, but device complexity and manufacturing costs increase due to different injector types and adjustments required

Engineering Contradiction:
Improveignition reliabilityVSAvoidinjector configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the parameter of fuel flow rate dynamically over time rather than using different physical injectors. The method implements three phases: initial phase with constant flow, second phase with rapid 20-30% flow increase to achieve rich mixture for reliable ignition, and third phase with gradual slower increase. This temporal parameter variation replaces the need for spatially differentiated injectors, resolving the contradiction between ignition reliability and device complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transforms the static injector configuration into a dynamic fuel injection system. Instead of having different injectors fixed in different positions, the system uses a single injector type that dynamically adjusts its flow rate through controlled phases. The rapid increase phase (20-30% boost in 1-2 seconds) creates the necessary fuel richness at spark plug locations temporarily, while the gradual increase phase sustains ignition without forming large flames that could impact the turbine

Inventive Principle:
Principle #15Dynamics

2Reliability

If different types of injectors are used with different flow rates, then ignition reliability is improved, but manufacturing and maintenance costs increase

Engineering Contradiction:
Improveignition reliabilityVSAvoidmanufacturing and maintenance cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent makes all injectors identical and universally applicable throughout the combustion chamber. The single injector type performs multiple functions: during the initial phase it provides base fuel flow, during the second phase it rapidly increases flow to create rich mixture for reliable ignition, and during the third phase it gradually increases flow to sustain combustion. This universal injector design eliminates the need for different injector types, keying means, and specialized adjustments, thereby reducing manufacturing and maintenance costs while maintaining ignition reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If fuel flow is rapidly increased by 20-30% in the second phase, then fuel richness is quickly increased to facilitate ignition, but large flames could form and impact the turbine if not controlled

Engineering Contradiction:
Improveignition facilitationVSAvoidlarge flame formation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses dynamic control of fuel flow rate with two distinct increase phases. The second phase provides a rapid 20-30% flow increase over 1-2 seconds to quickly achieve the fuel richness needed for reliable ignition. The third phase then transitions to a gradual, slower increase that sustains combustion while preventing excessive fuel accumulation that would create large flames. This dynamic two-stage increase strategy resolves the contradiction between facilitating ignition and preventing harmful flame formation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements periodic action through structured phases with different flow characteristics. The initial phase establishes base flow, the second phase provides a brief rapid increase pulse for ignition facilitation, and the third phase offers a prolonged gradual increase for stable combustion. This phased periodic approach ensures that the rapid fuel injection occurs only when needed for ignition, while subsequent controlled injection prevents harmful flame formation that could impact the turbine

Inventive Principle:
Principle #19Periodic action

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 ensures reliable ignition while reducing manufacturing and maintenance costs by using identical injectors, as the increased fuel richness facilitates rapid ignition without the need for specialized injectors, and the gradual fuel increase prevents excessive flame formation.

Implementation Method 1

ignition means, such as spark plugs, are mounted downstream of the injectors in orifices of the annular walls of the chamber and emerge inside the latter

Methodology Applied
Scientific EffectElectrical Discharge: Electric Spark

Implementation Method 2

a constant flow of fuel is injected inside the chamber simultaneously with the energizing of the ignition means

Methodology Applied
Scientific EffectFluid Spray: Fluid Spray

Data Source

PatentEP2591288B1Ignition procedure for a turbine engine combustion chamber
Publication Date: 2018.09.05 SAFRAN AIRCRAFT ENGINES SAS
  • EP2591288B1 patent drawingFigure 1~2
  • EP2591288B1 patent drawingFigure 3

AI summary

The invention relates to an ignition procedure for a turbine engine combustion chamber (10) supplied with fuel by injectors (26) and comprising means (28) for igniting the fuel injected into the chamber (10). This procedure comprises: an initial phase (36) during which a constant flow of fuel is injected into the chamber (10) at the same time as the ignition means (28) are energized; and, in the event of non-ignition in the chamber (10) at the end of the initial phase (36), a second phase (38) during which the injected-fuel flow rate is increased rapidly by 20 to 30%.