Boiler Steam Temperature Control via Burner Tilt and Damper Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Once-through boiler systems face challenges in controlling short-term fluctuations in steam temperature, leading to inefficiencies and potential damage to steam turbines, as traditional control methods like fuel/air mixture and firing rate adjustments are insufficient for precise temperature regulation, especially at varying load demands.
Innovation Solution
A controller is implemented that uses a combination of burner tilt positions, damper positions, and reheater spray flow to optimize steam temperature control, prioritizing reheater section manipulation for more direct impact on boiler efficiency and heat rate, rather than relying heavily on superheater spray, which reduces efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional control methods (fuel/air mixture and firing rate adjustments) are used to control steam temperature, then the system can maintain basic temperature regulation, but the control precision is insufficient for short-term fluctuations and varying load demands
Solution Approach 1:
The patent implements dynamic control by continuously adjusting burner tilt positions and damper positions based on real-time steam temperature measurements. The controller dynamically modifies the configuration of heating surfaces and flue gas flow paths to respond to short-term temperature fluctuations and varying load demands, transforming the static boiler system into a dynamically adjustable one.
Solution Approach 2:
The patent changes physical parameters of the boiler system by tilting burners to different angles and adjusting damper positions to modify flue gas flow characteristics. These parameter changes allow precise control of heat distribution and steam temperature without requiring complex additional control equipment, achieving better temperature precision through physical parameter adjustment.
2Temperature
If superheater spray is used to control steam temperature, then temperature regulation can be achieved, but boiler efficiency decreases
Solution Approach 1:
The patent applies preliminary action by adjusting burner tilt positions and damper configurations before steam temperature deviations become significant. The controller proactively modifies the heating surface distribution and flue gas flow paths to prevent temperature excursions, thereby avoiding the need for energy-intensive spray water injection and maintaining boiler efficiency.
Solution Approach 2:
The patent replaces the mechanical spray water injection system with a control system that adjusts burner tilt and damper positions. Instead of using water spray to cool steam (which causes energy loss), the system uses mechanical adjustment of fuel combustion geometry and flue gas flow to control steam temperature, substituting a less energy-intensive control mechanism.
3Productivity
If the system operates at varying load demands with constant steam temperature setpoints, then power output can be adjusted, but maintaining temperature within narrow ranges becomes increasingly difficult
Solution Approach 1:
The patent applies local quality by differentially adjusting burner tilt positions and damper openings for different sections of the boiler based on local temperature measurements and load conditions. Each burner and damper is independently controlled to maintain appropriate heat distribution across varying load demands, ensuring stable steam temperature at the outlet regardless of overall power generation level.
Solution Approach 2:
The patent implements feedback control by continuously measuring steam temperature and using this information to adjust burner tilt positions and damper configurations. The controller receives real-time temperature data and automatically modifies the heating surface distribution and flue gas flow paths to maintain the desired temperature setpoint, providing stable temperature control across varying load conditions through closed-loop feedback.
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 approach enhances boiler efficiency by providing more direct and immediate control over steam temperatures and heat rates, minimizing the need for secondary reheater spray operations, thus improving power generation performance and reducing energy costs.
Implementation Method 1
fuel burning boilers generate steam from water traveling through a number of pipes and tubes within the boiler... heat generated in a boiler, wherein the amount of heat is directly determined by the amount of fuel consumed
Implementation Method 2
boilers generate steam from water traveling through a number of pipes and tubes within the boiler
Implementation Method 3
heat which, in turn, is transferred to water flowing through pipes or tubes within various sections of the boiler
Implementation Method 4
the steam exiting this first steam turbine may then be reheated in a reheater section of the boiler
Implementation Method 5
saturated water is sprayed into the steam at a point before the final heat exchanger section located immediately upstream of the turbine
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A technique of controlling a boiler system such as that used in a power generation plant includes using manipulated variables associated with or control inputs to a reheater section of the boiler system to control the operation of the furnace, and in particular to control the fuel/air mixture provided to the furnace or the fuel to feedwater ratio used in the furnace or boiler. In the case of a once-through boiler type of boiler system, using the burner tilt position, damper position or reheater spray amount to control the fuel/air mixture or the fuel to feedwater flow ratio of the system provides better unit operational efficiency.