Three-Point Ignition Electrode Fixation for Burners
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Solution Overview
Problem
Existing attachment methods for ignition electrodes in gas turbines are prone to incorrect fastening due to surface quality fluctuations and shape inaccuracies, leading to thermal expansion issues, vibrations, and increased risk of breakage during installation and transport, which can result in misfiring and reduced service life.
Innovation Solution
A three-point fixation system for ignition electrodes, where each electrode is secured at 120° angles around its circumference, allowing for axial displacement to accommodate thermal expansion and radial resilience to absorb vibrations, using a combination of support and fixing clamps with a spring effect to ensure stable and reproducible natural frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single central screw clamp is used to attach ignition electrodes, then the attachment structure is simple, but the fastening quality is poor due to surface quality fluctuations and shape inaccuracies
Solution Approach 1:
The single central clamp is divided into three separate clamps distributed around the ignition electrode. Each clamp provides an independent attachment point, segmenting the fastening function to compensate for surface quality variations and shape inaccuracies at any single location.
Solution Approach 2:
Instead of requiring uniform quality across the entire electrode surface, the three-point fixation allows each local attachment point to be optimized independently. The clamps can be positioned at locations with better surface quality, while tolerating variations at other areas.
2Stability of the object's composition
If the clamp fastening is made tight to prevent thermal expansion, then thermal expansion is restricted, but the ignition electrode cannot accommodate thermal stresses
Solution Approach 1:
The clamps are designed with elastic deformation capability, allowing them to change their clamping force parameters in response to thermal expansion. This enables the system to maintain stable positioning while accommodating temperature-induced dimensional changes through controlled elastic deformation of the clamp components.
3Temperature
If the clamp fastening is made loose to allow thermal expansion, then thermal stresses are reduced, but undesired vibrations occur
Solution Approach 1:
The attachment system transitions from a rigid fixed connection to a dynamic elastic connection. The clamps can dynamically adjust their stiffness characteristics, providing firm holding under normal conditions while allowing controlled movement during thermal expansion, thus preventing both excessive vibration and thermal stress.
4Reliability
If the ignition electrode is glued into ceramic for insulation, then electrical insulation is provided, but the electrode becomes sensitive to impacts and may break
Solution Approach 1:
The clamp serves as an intermediary element between the ignition electrode and the burner body. Instead of directly embedding the electrode in ceramic (which creates a rigid brittle connection), the clamp provides a flexible mechanical interface that absorbs impact forces while maintaining electrical insulation through proper design.
5Ease of manufacture
If the clamp has a certain height due to minimum screw-in depth, then the screw can be properly fastened, but the distance to the diagonal grid becomes small causing misfiring
Solution Approach 1:
The attachment system transitions from a vertical height-based solution to a radial distribution solution. Instead of increasing the vertical height of the clamp to achieve proper screw fastening (which reduces clearance to the diagonal grid), the three clamps are distributed radially around the electrode, providing adequate screw-in depth while maintaining proper clearance in the critical ignition direction.
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 three-point fixation system provides a stable and reproducible attachment that compensates for thermal and radial expansions, reduces the risk of breakage, and prevents misfiring by maintaining optimal ignition gap distances, thus extending the service life and improving handling safety.
Implementation Method 1
Such an axial displacement of the ignition electrodes can be caused by thermal expansion of the ignition electrodes. Axial thermal stresses in the ignition electrode can be avoided by the axially displaceable bearing.
Implementation Method 2
The radial suspension enables vibrations to be compensated, which increases the service life of the ignition electrode.
Implementation Method 3
This can be realized in particular in that the holder comprises at least one radially resilient clip.
Implementation Method 4
The ceramic coating serves to electrically insulate the ignition electrodes and thus reduces their heat-related expansion.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Provided is a burner (3) having two ignition electrodes (4) and having a bracket (2), wherein the bracket (2) is arranged on the outer surface of the burner (3) and the ignition electrodes (4) are held, at in each case three points (1) of their periphery, in a fixed position by means of the bracket (2).