Turbine Combustion Chamber Flame Stabilization via Perforated Diffuser

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Microturbines with recuperators face challenges in flame stabilization due to high air temperatures, leading to instability and increased costs for materials and cooling systems, which complicates complete combustion and emission control.

Innovation Solution

A combustion chamber design featuring a perforated diffuser with concentric rows of holes of varying diameters and angular distributions, promoting fuel recirculation and air speed to stabilize the flame, allowing for leaner combustion and reduced pollutant production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If pre-mixed combustion with lean richness is used to achieve low emissions, then nitrogen oxides and carbon monoxide emissions are reduced, but flame stabilization becomes difficult due to high air temperatures from the recuperator

Engineering Contradiction:

Improvenitrogen oxides and carbon monoxide emissionsVSAvoidflame stabilization

Core Design Contradiction:

Object-generated harmful factorsVSReliability

Solution Approach 1:

The combustion chamber is divided into distinct zones: a primary combustion zone with a rich mixture for stable flame anchoring, and a secondary combustion zone with a lean mixture for low emissions. This spatial segmentation allows each zone to optimize for its specific function, resolving the contradiction between flame stability and emission reduction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different local conditions are created within the combustion chamber: the primary zone has high fuel concentration and recirculated hot gases to stabilize the flame, while the secondary zone has lean mixture for low emissions. This local differentiation allows simultaneous achievement of flame stability and low emissions.

Inventive Principle:

Principle #3Local quality

2Temperature

If a cooling system with multiple holes is implemented to protect burner walls from flame interaction, then wall temperature is controlled, but manufacturing cost and production complexity increase significantly

Engineering Contradiction:

Improveburner wall temperatureVSAvoidmanufacturing cost and production complexity

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

Instead of using a complex cooling system to protect the walls, the invention allows the flame to interact with the wall and converts this harmful interaction into a beneficial effect: the wall acts as a flame stabilizer, anchoring the flame and improving combustion stability. This eliminates the need for expensive cooling systems while achieving better flame stabilization.

Inventive Principle:

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

3Temperature

If expensive materials and cooling systems are used to handle strong flame-wall interaction, then burner wall temperature is controlled, but design cost increases

Engineering Contradiction:

Improveburner wall temperature control capabilityVSAvoidcooling system complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The harmful flame-wall interaction is converted into a beneficial flame stabilization mechanism. The wall serves as a flame anchor, and the recirculation passages enhance this effect by directing hot combustion gases along the wall to maintain attachment. This approach achieves temperature control capability without complex cooling systems.

Inventive Principle:

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

Solution Approach 2:

The combustion chamber wall serves its own protective function by stabilizing the flame, eliminating the need for separate cooling systems. The recirculation passages use the combustion gases themselves to maintain flame attachment to the wall, creating a self-sustaining system that reduces complexity.

Inventive Principle:

Principle #25Self-service

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 design achieves stable flame stabilization, reduces pollutant emissions, eliminates soot particles, and lowers temperature gradients, enabling efficient and low-emission combustion.

Implementation Method 1

a perforated diffuser (78) for the passage of hot compressed air, characterised in that it comprises a bore (82) for the passage of the fuel and two circumferential rows of holes (84) arranged concentrically with said bore

Methodology Applied

Scientific EffectRecirculation: Convection

Implementation Method 2

promoting fuel recirculation and air speed to stabilize the flame

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 3

a combustion chamber supplied with fuel by at least one reservoir

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentEP3430316B1Combustion chamber of a turbine, particularly a turbine with a thermodynamic cycle comprising a recuperator, for producing energy, particularly electrical energy

Publication Date: 2020.10.21 IFP ENERGIES NOUVELLES

Figure 1~2
Figure 3~4

AI summary

The invention relates to a combustion chamber (18) of a turbine, particularly a turbine with a thermodynamic cycle comprising a recuperator, for producing energy, particularly electrical energy, said combustion chamber comprising a housing (50) containing a fire tube (58) with a diffusion wall (60) carrying a flame stabiliser (72) comprising a perforated air diffuser (78) and a mixing tube (88), said chamber also comprising a means (64) for injecting at least one fuel. According to the invention, the perforated diffuser (78) comprises at least two peripheral rows (C1, C2) of holes (84; 84a, 84b).