Two-Layer Vortex Burner for Flame-Tube Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing burners for gas turbine plants face manufacturing complexity and require expensive thermal protection due to high inner surface temperatures, and they lack efficient stabilization of combustion processes at varying load conditions.
Innovation Solution
A burner design with a two-layer vortex countercurrent flow that includes a cylindrical body, flame tube, and coaxial nozzle, featuring an air duct, swirl nozzles at both the inlet and rear wall, and dual fuel feeders, creating near-axis and peripheral vortex flows to cool the inner surface and stabilize combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a conventional burner design with a flame tube is used, then combustion can be achieved, but the inner surface temperature becomes too high requiring expensive thermal protection coating
Solution Approach 1:
The air supply is segmented into two distinct streams: primary air through the swirl nozzle at the inlet window, and secondary air through the additional swirl nozzle at the rear wall. This segmentation allows independent control of cooling functions and combustion functions, enabling the cold air curtain to effectively protect the flame tube inner surface while maintaining combustion efficiency
Solution Approach 2:
Cold air is supplied through the additional swirl nozzle at the rear wall before it contacts the hot inner surface of the flame tube. This preliminary action of introducing cold air creates a protective layer that prevents direct heating of the flame tube surface, thereby reducing the need for expensive thermal protection coating
2Reliability
If a single-layer flow design is used, then the structure is simpler, but combustion stability at varying load conditions is insufficient
Solution Approach 1:
The burner structure is segmented into multiple functional components: swirl nozzle, additional swirl nozzle, fuel feeder, and additional fuel feeder. This segmentation allows each component to perform a specific function (primary mixing, secondary mixing, fuel injection, additional fuel injection), thereby improving combustion stability across varying load conditions while keeping each individual component relatively simple
Solution Approach 2:
The dual swirl nozzle and dual fuel feeder configuration provides multi-functionality: at full load, all components operate together for stable combustion; at partial load, only the primary swirl nozzle and fuel feeder are needed. This universality allows the burner to maintain combustion stability across a wide range of operating conditions without requiring complex variable geometry mechanisms
3Object-generated harmful factors
If high excess air factor is used for combustion, then emission performance improves, but combustion stability deteriorates
Solution Approach 1:
The burner creates different local air-fuel mixing conditions: the swirl nozzle creates a first fuel-air mixture with certain excess air factor, while the additional swirl nozzle creates a second mixture zone. This local quality differentiation allows the core combustion zone to maintain stability while the outer zones provide additional air for complete combustion and reduced emissions
Solution Approach 2:
The additional swirl nozzle at the rear wall changes the local air flow parameters by introducing a second air stream that modifies the velocity distribution and turbulence characteristics. This parameter change allows the combustion process to maintain stability even when operating with higher overall excess air factors, as the localized mixing zones ensure adequate fuel-air ratio for stable combustion
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
Reduces inner surface temperatures, eliminating the need for expensive thermal protection and enhances combustion stability at higher excess air factors, enabling efficient operation across varying loads.
Implementation Method 1
The additional swirl nozzle at the rear wall of the flame tube creates the peripheral vortex air movement near the inner surface of the tube, thus the surface of the flame tube is washed with 'cold' air from two sides
Implementation Method 2
the surface of the flame tube is washed with 'cold' air from two sides: from the air duct side and from the vortex created inside
Implementation Method 3
the reversal of the peripheral vortex at the front wall of the flame tube provides the stable zone of flame stabilization and combustion process in the near-axis part of the flame tube
Implementation Method 4
mixed with fuel to produce the first fuel-air mixture, and fed into the flame tube. From the second duct, swirling air or fuel-air mixture is also fed to the beginning of the flame tube and mixed with the first mixture
Data Source
AI summary
An invention relates to devices for combustion of gaseous fuels, in particular to vortex burners. The technical result consists in simplification of the burner design, allowing to reduce the temperature of the inner surface of the flame tube and, thus, to eliminate the need for expensive thermal protection coating, as well as in improving the stabilization of the combustion process and implementation of the possibility of combustion at higher excess air factors (poor mixtures) due to the formation of a countercurrent vortex flow inside the flame tube. The burner with the two-layer vortex countercurrent flow contains a cylindrical burner body, a flame tube, and a nozzle coaxially installed therein, wherein an air duct is provided between the burner body and the flame tube; the flame tube contains a front wall having an inlet window and a rear wall having the nozzle; the burner body contains an inlet window fuel feeder, whereas the air duct at the inlet window contains a swirl nozzle, with an additional swirl nozzle and an additional fuel feeder located at the rear wall, and the nozzle is partially placed inside the flame tube.