“Coal-fired Boiler Optimization” Hot Topic on September 27, 2012
Part 1 of the “Coal-fired Boiler Optimization” Hot Topic was conducted on September 27, 2012, and Part 2 is scheduled for October 11, 2012. The speakers this week provided information on comprehensive boiler assessments, smart firing systems, zonal combustion optimization systems and neural networks. These approaches can deliver heat rate improvements on the order of 0.5 to 1.5 percent. Peter Spinney also presented information regarding the regulatory requirement to demonstration boiler optimization efforts under the new MATS rule. The speakers this week were:
Don Labbe, a Consulting Control Engineer for Invensys Operations Management, presented information on a “Smart Firing Control System,” which recalibrates existing boiler optimization systems to account for a phenomenal called “roping.” Roping can occur when pulverized coal is fed into a boiler and can create an imbalance in the distribution of coal flow to the burners. This imbalance will cause some regions of the furnace to have more fuel than others, which also results in O2 and NOx imbalances.
Invensys developed the Smart Firing Control System to periodically test Advanced Process Control (APC) systems online without operator intervention and adapt the models to capture the characteristics of these shifting relationships. The solution can contribute to significant boiler efficiency improvements, above and beyond the original APC application. In the case of the Weston Unit #4, a supercritical unit in Wisconsin, a heat rate improvement of 0.12 percent was achieved, along with a 1.6 percent reduction in ammonia flow.
Richard (Dick) F. Storm, CEO/Senior Consultant of Storm Technologies, Inc., discussed a general approach to boiler optimization. Dick identified at least 22 controllable boiler heat rate variables which should be examined during a comprehensive boiler assessment. Boiler and ductwork ambient air in-leakage typically presents the greatest opportunity for improvement, with a potential heat rate improvement of 300 Btu/kWh and an annual fuel savings of $2.5 million for a 400-MW boiler. Other opportunities for heat rate improvement include balancing fuel distribution and fuel fineness, decreasing furnace exit gas temperatures, and addressing inaccurate overfire airflow measurement and control.
Neil Widmer, Manager of the Boiler Optimization Service group within GE Energy Services, and Antonio (Tony) Marquez, Product Manager for GE Boiler Optimization Services, discussed “Zonal™ Combustion Optimization for Coal-Fired Boilers.” GE’s Zonal™ Combustion Monitoring System focuses on adjusting the distribution of air and fuel in boiler zones to optimize combustion. They also discussed examples where severe slagging or furnace wall corrosion indicated the need to adjust O2 balances. The Zonal™ system provides continuous information so that operators and plant engineers can quickly adjust boiler/burner operational parameters to improve boiler performance and reduce emissions.
Peter Spinney, Director of Marketing and Technology Assessment at NeuCo Inc., discussed the CombustionOpt and SootOpt products developed by NeuCo to optimize boiler operations. He also discussed optimization requirements under the new Mercury and Air Toxics Standard (MATS) rule. Optimization of NOx and CO must be demonstrated and documented every three years under the new rule. Neural network systems such as Combustion Opt and SootOpt qualify as optimization demonstrations and receive favorable treatment under the rule. Units with those systems only have to demonstrate compliance every four years, rather than every three years.
The Bios, Abstracts and Photos can be seen at: Bios, Abstracts, Photos - September 27, 2012.htm
The individual presentations are as follows: