Gas Generator Injector with Dilution Nozzles for Combustion Control

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Solution Overview

Problem

Conventional gas generators face challenges in achieving uniform combustion states in both high-temperature and low-temperature zones while ensuring ignitability and flame-stability, and current methods for evaluating combustion states are complex and costly.

Innovation Solution

A gas generator design featuring a combustor with a plurality of injection elements, including unlike-impingement type fuel and oxidizer nozzles for combustion and additional nozzles for dilution, which injects oxidizer further forward to create a dilution point, allowing for efficient mixing and dilution of combustion gases to achieve stable and uniform combustion states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the mixture ratio is reduced by diluting with fuel to reduce combustion gas temperature, then the temperature of combustion gas is reduced, but ignitability and flame-stability deteriorate

Engineering Contradiction:
Improvecombustion gas temperatureVSAvoidignitability and flame-stability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The combustor is divided into multiple zones with different mixture ratios: a high-temperature combustion zone with appropriate mixture ratio for stable ignition, and a low-temperature combustion zone with fuel-rich mixture ratio for temperature reduction. This spatial segmentation allows simultaneous achievement of ignition stability and temperature control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the combustor are assigned different mixture ratio characteristics: the central region maintains appropriate mixture ratio for flame stability, while the outer region uses fuel-rich mixture ratio for cooling. This local differentiation resolves the contradiction between ignition requirements and temperature control.

Inventive Principle:
Principle #3Local quality

2Temperature

If the mixture ratio is reduced to reduce combustion gas temperature, then the temperature of combustion gas is reduced, but the combustion state becomes non-uniform

Engineering Contradiction:
Improvecombustion gas temperatureVSAvoidcombustion state uniformity
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The combustor is divided into multiple zones with different mixture ratios: a high-temperature combustion zone with appropriate mixture ratio for stable ignition, and a low-temperature combustion zone with fuel-rich mixture ratio for temperature reduction. This spatial segmentation allows simultaneous achievement of ignition stability and temperature control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the combustor are assigned different mixture ratio characteristics: the central region maintains appropriate mixture ratio for flame stability, while the outer region uses fuel-rich mixture ratio for cooling. This local differentiation resolves the contradiction between ignition requirements and temperature control.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If conventional evaluation methods are used to assess combustion states in both zones, then accurate combustion state assessment is achieved, but development cost increases

Engineering Contradiction:
Improvecombustion state evaluation accuracyVSAvoiddevelopment cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The invention uses a single-injection-element test method that replicates the essential combustion characteristics of the multi-zone combustor. By designing the test element to produce comparable flow patterns and mixture ratios, accurate combustion state evaluation can be performed with simplified, lower-cost testing rather than full-scale combustor testing.

Inventive Principle:
Principle #26Copying

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 design ensures secure ignitability and flame-stability in high-temperature zones and reduces combustion gas temperatures in low-temperature zones, enabling stable supply to turbopumps while simplifying the evaluation of combustion states, thus reducing development costs.

Implementation Method 1

one or more fuel injection nozzles for combustion and one or more oxidizer injection nozzles for combustion, which mix and burn each jet of the fuel and the oxidizer at a combustion point

Methodology Applied
Scientific EffectImpingement mixing:

Implementation Method 2

combustor configured to mix and burn the fuel and the oxidizer injected from the injector

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 3

one or more injection nozzles for dilution, which mixes an oxidizer for dilution injected toward a dilution point located forward further than the combustion point in front of the plane in the combustor, with a combustion gas generated at the combustion point

Methodology Applied
Scientific EffectDilution mixing:

Data Source

PatentEP3816426B1Gas generator
Publication Date: 2022.02.16 IHI CORP
  • EP3816426B1 patent drawingFigure 1
  • EP3816426B1 patent drawingFigure 2
  • EP3816426B1 patent drawingFigure 3

AI summary

A gas generator (GG includes an injector (1) for injecting a fuel and an oxidizer; and a combustor (2) for mixing and burning the fuel and the oxidizer injected from the injector (1), and for supplying a combustion gas of the fuel and the oxidizer as the driving fluid to the turbine of the turbopump. The injector (1) includes a plurality of injection elements (11) arranged on a same plane (10a). Each of the injection elements (11) includes one or more fuel injection nozzles (15) for combustion and one or more oxidizer injection nozzles (13) for combustion, which mix and burn each jet of the fuel and the oxidizer at a combustion point (CP) in front of the plane (10a) in the combustor (2), and one or more injection nozzles (17) for dilution, each mixing an oxidizer for dilution injected toward a dilution point (DP) located forward further than the combustion point (CP) and in front of the plane (10a) in the combustor (2), with a combustion gas generated at the combustion point (CP).