Annular Combustion Burner Partition Plate Flashback Suppression
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Solution Overview
Problem
Combustion burners face challenges in suppressing flashback, particularly in regions with low axial velocity and high fuel density, where flames can propagate backward, causing damage to nozzles and surrounding structures.
Innovation Solution
A combustion burner design featuring a swirl vane with a fuel injection hole in an annular air flow passage that divides the passage into inner and outer flow passages, preventing fuel entry into the inner film layer and enhancing axial velocity, thereby reducing the risk of flashback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If fuel is injected into the air flow passage through swirl vanes, then combustion performance is improved, but fuel may enter the film layer and cause flashback
Solution Approach 1:
The air flow passage is divided into an inner passage and an outer passage by the partition plate. The inner passage carries film air that forms a protective layer on the nozzle, while the outer passage carries fuel-containing air. This segmentation prevents fuel from entering the film layer, eliminating flashback risk while maintaining combustion performance.
Solution Approach 2:
Different regions of the air flow passage are given different functions: the inner passage provides fuel-free film air for protection, while the outer passage provides fuel-containing air for combustion. This local differentiation ensures that fuel remains in regions with higher axial velocity away from the nozzle surface.
2Stability of the object's composition
If the axial velocity is reduced in the center region of swirl flow, then combustion stability is improved, but flashback risk increases due to low velocity and high fuel density
Solution Approach 1:
The flow passage is segmented into inner and outer regions. The inner passage delivers fuel-free film air to maintain low fuel density near the nozzle, while the outer passage allows fuel injection for combustion stability. This spatial separation resolves the contradiction by ensuring fuel and film air do not mix.
Solution Approach 2:
The partition plate acts as an intermediary structure that separates the fuel-containing outer flow from the fuel-free inner flow. It prevents direct mixing while allowing both flows to coexist and perform their respective functions without causing flashback.
3Object-affected harmful factors
If a film layer is formed to cover the nozzle, then flashback is suppressed to some extent, but fuel can still enter the film layer and cause flashback
Solution Approach 1:
The air flow is segmented into two separate streams: film air through the inner passage that remains fuel-free, and combustion air through the outer passage that contains fuel. This ensures the film layer is exclusively formed by fuel-free air, making flashback prevention reliable and complete.
Solution Approach 2:
The film air in the inner passage is specifically characterized as fuel-free, creating a localized region with zero fuel density near the nozzle surface. This local quality control ensures absolute prevention of flashback at the nozzle while maintaining overall combustion performance.
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
Effectively suppresses flashback by maintaining high axial velocity and low fuel density in critical regions, preventing damage to the nozzle and improving the durability of combustion burners and gas turbines.
Implementation Method 1
a swirler for swirling air
Implementation Method 2
a laminar flow formed in the vicinity of the wall surface of the air flow passage
Data Source
AI summary
A combustion burner includes a nozzle, a swirl vane having a fuel injection hole, the swirl vane being disposed in an air flow passage of an annular shape extending along an axial direction of the nozzle around the nozzle, and a partition plate having an annular shape and partitioning at least a region of the air flow passage in a radial direction of the nozzle, so as to divide at least the region into an inner flow passage facing an outer peripheral surface of the nozzle and an outer flow passage disposed on an outer side of the inner flow passage with respect to the radial direction. The fuel injection hole is disposed in the outer flow passage of the air flow passage. An end portion on an upstream side of the partition plate is disposed upstream of the fuel injection hole in the axial direction.