PROCESS OPTIMIZATION FOR POWER PLANTS - POWITEC

A combination of optical sensors for flame analysis and acoustical sensors for mill analysis with self learning and adaptive software optimizes the fuel/air-ratio and allocation. All process and flue gas data is permanently correlated with the optical and acoustical information in software using innovative neural nets and the overall process is continuously controlled to its optimum.

Challenges
Powitec’s Solution
Advantages
Results
Brochure/Documents

Difficulties for each control system arise from the complexity of the process and the constantly changing process conditions. Frequent tasks in coal dust fired large Power Plants are:

Optimization of combustion processes.
Reduction of Emission.
Varying coal qualities: Calorific Value, Ash content, Volatiles, Grindability etc.
Sometimes insufficient coal type information.
Unbalanced coal dust feed distribution (Unsymmetrical tubing, insufficient data).
Suboptimal combustion air distribution (Staged air burners, discontinued burner optimization, variation in coal grinding level & ignition point).
Extension of periods between maintenance outages.
To reduce of wear & Slagging.
To Increase of performance dynamics.
Fluctuating fuel characteristics.
Narrow emission limits.
Boiler Specific Challenges are: CO-peaks caused by slagging and/or a suboptimal air/fuel ratio.
Unsymmetrical temperature distribution, High content of unburned C in fly ash.

POWITEC’S PIT NAVIGATOR

The PiT Navigator System consists of specially developed optimized package consisting of sensors for the combustion chamber – PiT Multi-Sensors, Image processing software for flame analysis, Optical sensors for flame analysis and acoustical sensors for analysis of level of grinding as well as self-learning adaptive information compressing modules and control modules based on neural nets to achieve continuous air/fuel optimization ratio.

Exactly here is where Powitec Intelligent Technologies' (PiT) Optimization systems come into the picture!

The central product PiT Navigator optimizes processes with autarkic, self learning and continuously re-adapting Software. Through optical sensors and highly sophisticated neural nets (artificial intelligence), the technical control system receives “eyes and brain“!

To a substantial extent energy efficiency increases as well as emission lowering are achieved by first-time adoption of specifically developed multi-sensors in combination with image processing and information compression modules as well as a multi-dimensional automatic controller on basis of neural software nets. This is at present the highest level of development in industrial combustion optimization.

Online flame structure characteristics by image processing / frequency analysis.
Online mill and coal characteristics by frequency analysis.
Self learning, adaptive combustion optimization by innovative neural net technology.

The PiT Navigator includes:

1. High-Speed cameras observe the combustion chamber and - through a patented pattern recognition process - extract significant features of the ignition, combustion and burnout- behavior.

2. A vibration pick-up captures mill vibrations which are being evaluated by a high performance computer. From these vibration- data, early information on degree of milling and coal quality are derived.

3. The process data from the control and communication system are permanently read online via interface. The PiT Navigator correlates these data with the optical and acoustical information through software based on neural nets.

For process modeling too, a system of neural nets is applied, capable of displaying the time-varying dependencies between the values to be optimized and the plant's controlled variables and disturbance variables. A simulation detects all target values and determines the optimal combination of controlled variables. The set point corrections calculated by the PiT Navigator are being transferred to the control system over the interface. The improved correcting instructions continuously control towards the optimum. In this way, the PiT Navigator optimizes the air/ fuel distribution per burner and over the burner levels.

The PiT Navigator is the ideal Solution for optimizing the process and/or sorting out complex problems (i.e. high Slagging, high content of unburned coal in ash, etc.).

PiT Navigator = ↑ Efficiency ↑ Availability ↓ Emissions

The complete integration of the results of digital optical and acoustical sensor technology in automatic control.
Advanced Combustion Control through innovative sensor technology and intelligent control worldwide.
Completely self-learning and adaptive controller, which permanently adjusts to changing process conditions.
Controlled flame position and burner characteristics flame root and volume near the burner, fire roll in the combustion chamber.
Increased Efficiency through minimizing fuel usage and auxiliary power (Lambda, unburned carbon in ash, temperature flue gas, CO).
Control of grain spectrum in co-action with burn out behavior and residence time.
Improvement of limiting values and emissions through improvement of air/fuel ratio and distribution, therefore reduction of unburned coal in ash, reduction of CO and NOx.
Positive effects on the boiler less contamination + maintenance, improved boiler wall atmosphere, stable operation mode.
Larger primary fuel band, larger variety of coal types and improvement of co-combustion of secondary fuels.
Increased performance dynamics through reduction of boiler response time through control of the flame centre and the mill system.
Reduction of slagging and soiling at burner mouth and finned walls through control of burner behavior, flame position, flame root and -volume, fire expansion within the combustion chamber, therefore significant availability increase.
Full-automatic permanent optimization of the boiler operation towards the management's target and priorities.

Results through an optimized air/ fuel distribution in the combustion chamber:

Reduced coal consumption up to 1%
Increased boiler efficiency of up to 0.5%
Reduced CO and NOx up to 30%.
Reduced unburned carbon in ash 1%.
Increased coal band.
30% improvement of performance dynamics.
Reduction of the boiler time constant by approx 30%.
Homogenized temperature distribution.
Increased combustion chamber temperature.
Optimized temperature distribution over the different levels, following acquired conditions.
Increased efficiency of steam generation.
Enlargement of varieties of used coal types.
Reduction of slagging and soiling at burner mouth and finned wall.
Increase of availability e.g. through elimination of back-firing.
Reduction of unburned coal in ash boiler geometries and ash-containing coal.