Premixing Combustion Apparatus for NOx Reduction

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Solution Overview

Problem

Conventional combustion apparatuses face challenges in reducing NOx generation and maintaining a stable flame at a position distant from the outlet, as they require complex multi-staged combustion and often rely on pilot flames to prevent flame blowout.

Innovation Solution

A combustion apparatus with a modifying part that converts hydrocarbon fuel into high-temperature hydrogen gas, which is discharged centrally and then jetted with air from an outer supply part to form a flame at a pre-set distance from the outlet, ensuring uniform mixing and reducing NOx generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If multi-staged combustion is used to reduce NOx generation, then NOx generation is reduced, but flame length increases and device structure becomes complicated

Engineering Contradiction:
ImproveNOx generationVSAvoiddevice structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-mixing fuel and air in a dedicated mixing chamber before combustion. This pre-mixing ensures uniform fuel-air distribution, allowing combustion to occur more efficiently and reducing NOx generation without requiring complex multi-staged combustion systems. The mixing chamber prepares the fuel-air mixture in advance, simplifying the overall device structure while achieving the desired emission reduction.

Inventive Principle:
Principle #10Preliminary action

2Object-generated harmful factors

If fuel and air are mixed rapidly to reduce NOx generation, then NOx generation is reduced, but a pilot flame and ignitor are required to prevent flame blowout

Engineering Contradiction:
ImproveNOx generationVSAvoiddevice structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies self-service by designing a system where the rapid mixing of fuel and air inherently stabilizes the flame without requiring external pilot flames or ignitors. The uniform pre-mixed fuel-air combination creates a stable combustion front that self-sustains, eliminating the need for additional pilot flame systems or ignitor components while maintaining rapid mixing benefits for NOx reduction.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If flame is formed at a position distant from the outlet, then mixing time is increased and uniform mixing is achieved, but flame stability becomes difficult to maintain

Engineering Contradiction:
Improvemixing uniformityVSAvoidflame stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-mixing fuel and air in a controlled mixing chamber before the flame formation zone. This ensures that when the mixture reaches the distant flame formation position, it is already uniformly combined, maintaining flame stability despite the extended distance from the outlet. The pre-prepared uniform mixture prevents flame instability that would otherwise occur with prolonged exposure to ambient conditions.

Inventive Principle:
Principle #10Preliminary action

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 stabilizes the flame at a distance from the outlet, allowing for longer mixing time and uniform fuel-air mixing, effectively reducing NOx generation while avoiding flame blowout.

Implementation Method 1

a modifying part configured in the center to modify supplied hydrocarbon-based fuel and air and discharge high temperature modified gas including hydrogen to an outlet

Methodology Applied
Scientific EffectPartial oxidation: Oxidation

Implementation Method 2

a supply part configured at an outer side of the outlet to jet fuel and air to one side of the modified gas discharged from the modifying part to form a flame at a position spaced apart by a pre-set distance from the outlet

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2696140B1Combustion apparatus with premixing element
Publication Date: 2020.09.02 KOREA INST OF MACHINERY & MATERIALS
  • EP2696140B1 patent drawingFigure 1
  • EP2696140B1 patent drawingFigure 2
  • EP2696140B1 patent drawingFigure 3

AI summary

Combustion apparatus (1) for reducing generation of NOx by securing more time for mixing fuel and air and uniformly mixing fuel and air and including a modifying part (100) configured in the center to modify supplied hydrocarbon-based fuel and air and discharge high temperature modified gas including hydrogen to an outlet (101) and a supply part (200) configured at an outer side of the outlet (101) to jet fuel and air to one side of the modified gas discharged from the modifying part (100) to form a flame at a position spaced apart by a pre-set distance from the outlet (101).