Laser Igniter for Coal-Fired Burner Flame Stability at Low Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Coal-fired power plants face challenges in maintaining grid stability due to the cyclic nature of renewable energy sources, requiring operation at low power and frequent start-ups, which complicates burner flame stability and increases operational costs with current oil-based and plasma igniter systems.
Innovation Solution
A laser igniter system that uses high-power laser beams to ignite pulverized coal particles within a custom-designed burner, achieving stable flame generation without the need for oil or complex plasma igniters, by directing laser light to focus on coal particles to reach ignition temperature and propagate the flame through cascading ignition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oil-based igniters are used to generate support flame, then flame stability is improved, but operational costs increase and corrosion occurs due to sulfur presence
Solution Approach 1:
The patent replaces the mechanical/chemical oil-based ignition system with a laser-based optical ignition system. The laser igniter uses high-energy laser beams to directly ignite coal particles, eliminating the need for oil combustion and associated corrosion problems while maintaining reliable flame generation.
Solution Approach 2:
The patent introduces a laser igniter as an intermediary device between the fuel source and combustion chamber. This intermediary uses laser energy to pre-heat and ignite coal particles before they enter the main combustion zone, providing stable flame initiation without using corrosive oil-based fuels.
2Reliability
If plasma igniters are used to ignite coal directly, then flame generation is achieved, but auxiliary power requirements increase and equipment complexity increases
Solution Approach 1:
The patent replaces the complex plasma generation system (requiring high voltage sources, electrodes, and medium-voltage cables) with a laser-based optical system. The laser igniter delivers energy through optical fibers or free-space beams, eliminating bulky electrical equipment and reducing auxiliary power requirements while maintaining effective coal ignition.
3Adaptability or versatility
If plants operate at low power to stabilize grid, then renewable energy integration is improved, but burner flame stability degrades
Solution Approach 1:
The patent implements a dynamic ignition system that can adapt to varying load conditions. The laser igniter can be activated on-demand during low-power operations to maintain flame stability, and its energy output can be modulated to match the specific requirements of different operating conditions, enabling reliable combustion across the full load range.
Solution Approach 2:
The patent applies preliminary heating action by using the laser igniter to pre-heat coal particles before they enter the main combustion zone. This preliminary energy input ensures that ignition occurs reliably even at low power levels where the main combustion process might otherwise struggle to establish stable flames.
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 laser igniter system provides stable flame support at low power conditions, reduces operational costs, and minimizes maintenance needs compared to plasma igniters, while maintaining efficient coal combustion, thus enhancing grid stability and reducing fatigue on power plant components.
Implementation Method 1
a laser source; a laser tube to deliver a beam of laser light from the laser source to the fuel in the fuel transport tube
Implementation Method 2
a beam of laser light heats and ignites the fuel in the ignition tube
Implementation Method 3
the beam of laser light heats and ignites the fuel in the ignition tube
Implementation Method 4
an ignition tube disposed within the fuel transport tube to receive a portion of fuel flowing through the fuel transport tube
Data Source
AI summary
A system and method of igniting a coal air-fuel mixture, including a burner having a burner tube operable to carry a flowing mixture of fuel and air to a furnace for combustion therein and a first flow directing device disposed within the tube, operable to direct a first portion of the flowing fuel and air mixture to a location in the burner tube. The system also includes a laser igniter within the burner tube, the laser igniter including a laser tube having a first end with a laser light input and a second end with a light output, and a laser light source operably coupled to the laser light input. The laser light source, including a laser. The laser ignitor directing photons from the light output at the location in the burner tube to ignite at least a part of the first portion of the fuel.