Fuel Injection Device with Reverse Passages for NOx Reduction
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Solution Overview
Problem
Existing fuel injection devices for gas turbines fail to achieve uniform distribution of fuel gas and water vapor in the combustion chamber, leading to insufficient reduction of NOx in exhaust gas, with existing solutions either lacking specific configurations or being difficult to implement effectively.
Innovation Solution
A fuel injection device with a nozzle housing containing a mixing chamber, first and second introduction passages for fuel gas and water vapor, and reverse passages that deflect the flow by 180°, ensuring thorough premixing of fuel gas and water vapor over a longer distance, resulting in a uniform concentration distribution and effective NOx reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If liquid fuel and water vapor are injected separately into the combustor, then the injection system is simple, but the concentration distribution of fuel and water vapor in the combustion chamber becomes non-uniform, resulting in insufficient NOx reduction
Solution Approach 1:
The patent applies preliminary action by premixing liquid fuel and water vapor in a mixing chamber before injection into the combustor. The fuel and water vapor are introduced separately through introduction passages, mixed in the mixing chamber, and then injected together through injection holes, ensuring uniform concentration distribution in the combustion chamber while maintaining a simple injection system structure.
2Device complexity
If fuel and water are injected separately, then the injection structure is simple, but the mixing occurs only after injection leading to non-uniform distribution and insufficient NOx reduction
Solution Approach 1:
The patent performs the mixing action in advance within the mixing chamber before injection. Liquid fuel and water vapor are premixed in the mixing chamber and then injected together through the injection holes, ensuring uniform distribution in the combustion chamber and effective NOx reduction while keeping the injection structure simple.
3Object-generated harmful factors
If hydrogen fuel with fine water droplets is injected to reduce flame temperature, then NOx reduction may be achieved, but the specific configuration is not disclosed and effective reduction cannot be expected
Solution Approach 1:
The patent applies preliminary action by premixing liquid fuel and water vapor in a mixing chamber before injection. This specific configuration ensures that fuel and water vapor are thoroughly mixed and injected together, achieving effective NOx reduction through uniform concentration distribution in the combustion chamber.
4Stress or pressure
If liquid fuel is used for premixing with water vapor, then fuel injection pressure can be reduced, but uniform distribution of fuel and water vapor in the combustion chamber is difficult to achieve
Solution Approach 1:
The patent applies preliminary action by premixing liquid fuel and water vapor in a mixing chamber before injection. This pre-mixing process ensures uniform concentration distribution of fuel and water vapor in the combustion chamber while maintaining reduced fuel injection pressure, as the mixing occurs before injection rather than requiring high-pressure injection for mixing.
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 device achieves a uniform distribution of fuel gas and water vapor, reducing NOx emissions efficiently while minimizing the amount of water vapor required, enhancing the overall efficiency of the gas turbine system and maintaining a simple, cost-effective structure.
Implementation Method 1
a plurality of reverse passages communicating with a downstream end of the mixing chamber and configured allow for a plurality of reverses of flow of mixed gas from the mixing chamber. In the description herein, the term 'reverse' means that the direction of the flow is deflected by 180°.
Implementation Method 2
the fuel gas and the water vapor are introduced into the mixing chamber of the nozzle housing to generate mixed gas, and, while the flow of the fuel gas and the water vapor is repeatedly reversed through a plurality of reverse passages a plurality of times, the fuel gas and the water vapor are further mixed in the mixing chamber over a longer travel distance for a longer time period.
Data Source
AI summary
A fuel injection device, for a gas turbine, which enhances uniform distribution in concentration of fuel gas and water vapor in a combustion chamber with simple structure and at low cost to effectively reduce NOx, is provided. The fuel injection device with a fuel nozzle to mix fuel gas and water vapor and inject the fuel gas and water vapor into a combustion chamber, includes: a nozzle housing having a mixing chamber thereinside; a first introduction passage to introduce the fuel gas into the mixing chamber from outside of the nozzle housing; and a second introduction passage to introduce the water vapor into the mixing chamber from an outside of the nozzle housing; and a plurality of reverse passages communicating with a downstream end of the mixing chamber and configured to allow for a plurality of reverses of flow of mixed gas from the mixing chamber.