Dual Plenum Micromixer for Turbine Flame Stability
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Solution Overview
Problem
Turbine systems face challenges in maintaining stable operation and reducing emissions during low flame temperature conditions due to a narrow fuel-to-air ratio, leading to loss of jet flame and high emissions.
Innovation Solution
A micromixer system with a casing, multiple pipes, and dual plenums is designed to enhance turndown capability by fluidically coupling fuel plenums to pipes, allowing for varying fuel-to-air ratios, ensuring stable combustion and reduced emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single fuel plenum is used to mix fuel and air, then the mixing process is simple, but the fuel-to-air ratio cannot be adjusted across a wide range, leading to loss of jet flame at low loads
Solution Approach 1:
The single fuel plenum is divided into two separate fuel plenums: a first fuel plenum that mixes fuel with air in pipes to create an air-fuel mixture, and a second fuel plenum that supplies additional fuel through openings surrounding the pipe outlets. This segmentation allows independent control of fuel delivery mechanisms to achieve a wide adjustable fuel-to-air ratio range while maintaining system functionality.
Solution Approach 2:
The patent combines two different fuel delivery approaches (fuel mixed within pipes and fuel supplied through surrounding openings) into a unified micromixer system. This merging of multiple fuel supply methods enables flexible fuel-to-air ratio adjustment across different operating conditions, resolving the contradiction between adaptability and complexity.
2Adaptability or versatility
If the fuel-to-air ratio is kept narrow for stable operation, then emissions are reduced, but the system cannot adapt to low flame temperature conditions, resulting in loss of jet flame
Solution Approach 1:
The system dynamically adjusts the fuel-to-air ratio by controlling the flow from both fuel plenums based on operating conditions. The first fuel plenum provides base mixing while the second fuel plenum supplements fuel delivery, allowing the system to adapt fuel delivery to match varying load conditions and maintain flame stability across a wide operating range.
Solution Approach 2:
The patent changes the fuel delivery parameters by introducing a second fuel plenum that can independently adjust fuel flow through the openings. This parameter change enables the system to maintain appropriate fuel-to-air ratios across different operating conditions, preserving flame stability while expanding adaptability to low flame temperature conditions.
3Adaptability or versatility
If a dual fuel plenum system is implemented to vary fuel-to-air ratios, then turndown capability is enhanced, but the device structure becomes more complex
Solution Approach 1:
The second fuel plenum is positioned locally around the outlets of the pipes with openings that surround specific pipe outlets. This local quality approach allows fuel supplementation at the critical outlet region where it is most needed, achieving enhanced turndown capability while minimizing the overall structural complexity by concentrating the additional components only where required.
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 achieves stable combustion and low emissions by adjusting fuel ratios, maintaining flame stability from low to high temperature conditions, thereby improving turndown capability and operational efficiency.
Implementation Method 1
fuel from the first plenum enters the plurality of pipes and is mixed with air within the plurality of pipes to generate an air-fuel mixture
Implementation Method 2
The combustion chamber is configured to combust the air-fuel mixture and the second fuel
Data Source
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AI summary
A micromixer system 308 includes a casing 146 having a first side wall 156 and a second side wall 158. Further, the micromixer system includes a plurality of pipes 148 spaced apart from each other and disposed within the casing. Each pipe includes an inlet 162 and an outlet 164 formed in the first and second side walls respectively. The micromixer system includes a first plenum 150 having a first inlet formed in the casing. The first plenum is disposed around a first portion 168 of the plurality of pipes and fluidically coupled to the plurality of pipes. The micromixer system includes a second plenum 152 having a second inlet formed in the casing and disposed around a second portion 176 of the plurality of pipes. Further, the micromixer system includes a plurality of openings formed in the second side wall, surrounding the outlets of at least some pipes of the plurality of pipes, and fluidically coupled to the second plenum.