Downstream Fuel Injector Segmentation for Gas Turbine NOx Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines face challenges in reducing NOx production due to the combustion of fuel in the main combustion zone, as existing systems do not effectively manage fuel distribution to minimize NOx formation.
Innovation Solution
An air/fuel supply system with downstream fuel injectors that distribute fuel into a secondary combustion zone, creating a homogeneous air/fuel mixture and reducing residence time for combustion reactions, thereby minimizing NOx production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If fuel is burned in the main combustion zone, then power generation is achieved, but NOx production increases
Solution Approach 1:
The fuel injection system is segmented into multiple independent injectors positioned at different locations within the combustor. Primary injectors deliver fuel to the main combustion zone while secondary injectors deliver fuel to downstream regions, allowing separate optimization of power generation and NOx reduction for each zone
Solution Approach 2:
Different regions of the combustor are given different combustion characteristics: the main combustion zone operates with higher temperature and intensity for power generation, while downstream regions operate with lower temperature and extended residence time to minimize NOx formation, creating local quality differences in combustion behavior
2Object-generated harmful factors
If fuel is injected downstream from main combustion zone, then NOx production is reduced, but combustion completeness may be compromised
Solution Approach 1:
The combustion process is merged into multiple zones with different characteristics. The primary combustion zone provides complete combustion for power generation, while secondary downstream zones complete the combustion process and reduce NOx formation, combining the advantages of both high efficiency and low emissions
Solution Approach 2:
Fuel is pre-mixed with air in the downstream regions before combustion occurs, creating homogeneous mixtures that burn completely and efficiently. This preliminary mixing action ensures complete combustion while the extended residence time in cooler downstream zones prevents NOx formation
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 system effectively reduces NOx production by injecting fuel downstream from the main combustion zone, maintaining lower combustion zone temperatures and minimizing diffusion-type combustion, resulting in reduced NOx emissions and efficient operation.
Implementation Method 1
The fuel supply structure is located in the main body and includes at least one fuel inlet that receives fuel from a source of fuel and a plurality of fuel outlets, each fuel outlet communicating with and supplying fuel to at least one of the air/fuel passages. Air passing through each air/fuel passage is mixed with fuel from at least one of the fuel outlets, the mixing occurring within each air/fuel passage to produce an air/fuel mixture within each air/fuel passage.
Implementation Method 2
Air passing through each air/fuel passage is mixed with fuel from at least one of the fuel outlets, the mixing occurring within each air/fuel passage to produce an air/fuel mixture within each air/fuel passage.
Data Source
AI summary
A fuel injector for use in a gas turbine engine combustor assembly. The fuel injector includes a main body and a fuel supply structure. The main body has an inlet end and an outlet end and defines a longitudinal axis extending between the outlet and inlet ends. The main body comprises a plurality of air/fuel passages extending therethrough, each air/fuel passage including an inlet that receives air from a source of air and an outlet. The fuel supply structure communicates with and supplies fuel to the air/fuel passages for providing an air/fuel mixture within each air/fuel passage. The air/fuel mixtures exit the main body through respective air/fuel passage outlets.