Gas Turbine Combustor Water Injection Nozzles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In dual-burning combustors, water supplied to the air flow channel tends to adhere to the inner peripheral surface due to centrifugal force, reducing its effectiveness in reaching the flame and thus limiting the reduction of NOx and soot.
Innovation Solution
The combustor design includes water injection parts with first and second nozzles on the inner peripheral surface of the outer cylinder, injecting water towards the radially inner side, which atomizes and evaporates before reaching the fuel nozzle, enhancing dispersibility and reducing NOx and soot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If water is supplied to the air flow channel between the outer cylinder and combustor liner, then flame temperature and NOx emissions are reduced, but water adheres to the inner peripheral surface due to centrifugal force and fails to reach the flame
Solution Approach 1:
The water injection direction is inverted from the conventional approach. Instead of injecting water into the air flow channel where centrifugal force pushes it outward, water is injected from the inner peripheral surface of the outer cylinder toward the radially inner side, counteracting the centrifugal force and ensuring water reaches the flame zone effectively
Solution Approach 2:
The water injection system is segmented into multiple water injection parts provided at intervals in the circumferential direction. Each water injection part includes first and second nozzles that inject water in different circumferential directions, creating non-uniform distribution and enhancing dispersibility of liquid droplets
2Reliability
If water is injected from the inner peripheral surface of the outer cylinder toward the radially inner side, then liquid droplets are less affected by centrifugal force and reach the fuel injection zone, but water must be precisely delivered to the correct position
Solution Approach 1:
The water injection system is divided into multiple discrete water injection parts positioned at intervals in the circumferential direction. This segmentation allows for more manageable positioning and installation of individual nozzle assemblies, reducing the overall complexity and precision requirements compared to a continuous injection system
3Object-generated harmful factors
If multiple nozzles are provided at intervals in the circumferential direction, then liquid droplet dispersibility is enhanced and NOx reduction is improved, but device complexity increases
Solution Approach 1:
Each water injection part is designed as a universal module that can be repeatedly installed at different circumferential positions. The standardized design of water injection parts allows for easy manufacturing and installation, reducing overall system complexity despite having multiple injection points
Solution Approach 2:
The circumferential direction is divided into multiple segments with water injection parts positioned at intervals. This segmentation approach achieves effective droplet dispersibility without requiring continuous circumferential coverage, optimizing the balance between performance and complexity
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 configuration ensures that water droplets are less affected by centrifugal force, improving their distribution and evaporation, leading to further reduction of NOx and soot, and increasing the output of the gas turbine by generating steam.
Implementation Method 1
The injected liquid droplets are sent into the combustor liner together with the air. Therefore, the liquid droplets are atomized and easily evaporated before reaching a portion where the fuel is injected from the fuel nozzle
Implementation Method 2
the water supplied from the water supply part into the air flow channel tends to adhere to an inner peripheral surface on a radially outer side of the reversing part due to a centrifugal force acting on the water at the reversing part
Data Source
AI summary
A combustor includes an outer cylinder, a combustor liner, a plurality of main nozzles, an air flow channel part, and a plurality of water injection parts. The air flow channel part sends air introduced from an outside to between an inner peripheral surface of the outer cylinder and an outer peripheral surface of the combustor liner into the combustor liner. The plurality of water injection parts are provided on the inner peripheral surface of the outer cylinder at intervals in a circumferential direction around a central axis. The plurality of water injection parts inject water into the air flowing through the air flow channel part. The water injection part includes a first nozzle and a second nozzle. The first nozzle injects water to a first side in the circumferential direction. The second nozzle injects water to a second side in the circumferential direction.