Monitoring and Optimizing Fuel Feed, Metering and Combustion in Boilers” was the Hot Topic for Thursday, June 13, 2013

 

Optimizing fuel feed rate and distribution in the boiler is one sure way to improve combustion efficiency.

 

Four  speakers provided their power points and were ready to help us understand the process of improving fuel feed; distribution and combustion efficiency; how to obtain optimum efficiency, availability and performance; describe the technologies available and under development with their applicability, capabilities, and limitations; costs involved and the benefits that can be attained. Unfortunately there was a web-related problem and two the speakers will be making their presentations at another time.

 

Steve Ullom of Babcock & Wilcox Power Generation Group, was prepared to discuss the benefits of the Even Flow System for balancing fuel flow to burners. B&W has successfully balanced coal flow in a roll wheel style pulverizer using a system of internal elements known as the Even Flow System. By affecting the coal flow in the turret of the pulverizer, there is a lesser impact on the primary air distribution when moving the solid stream.  Two methods have been used to determine the needed bias of Even Flow elements, Flame Doctor flame quality and air/fuel index along with overall CO emissions from the plant. Using this methodology, Even Flow was able to reduce CO emissions by over 100 ppm by improving coal distribution to the burners. Steve was one of the speakers able to hear but not communicate. So he will give his presentation in a later Hot Topic Hour. In the meantime we are displaying the power points.

 

Dave Early, Co-founder of Combustion Technologies, discussed control of coal feed to the burners in a boiler. Proper metering of coal to the boiler is critical, not just to load control, but to emissions, efficiency and reliability. Accurate fuel feed to the mills, combined with accurate fuel feed to the burners, will result in the best controllability of the boiler as well as the ability to reduce CO, NOx and LOI.  This talk focused on the bulk control to the mill as well as control of the coal in the individual pipes to the burners. Real time, continuous burner line coal flow measurement and precision control coal valves are some of the highlighted products used to achieve these goals. His presentation is one of the two you can listen to in the recording.

 

Robert E. Sommerlad, P.E. Consultant, was to present “The Case for Fuel Delivery System Upgrades for Utility Boilers.”  Boilers 50 years and older comprise about 53 GW or 20 percent of the total fleet capacity and 40 percent of all coal-fired units. Most of these will be retired due either to normal business decisions or to mandated upgrades to the air pollution control systems. The next age group, the 30- to 45-year old units, comprise 216 GW and 63 percent of the fleet with an average capacity of 500 MW.  These units will bear the burden of ensuring the usual high standards of performance, availability and reliability. A vital part of any coal-fired unit is the Fuel Delivery System (FDS), comprising equipment from the silos to the burners, including feeders, pulverizers, coal piping and burners. A committee of users, suppliers and architect / engineers under an ASME Research Committee has investigated three typical 500-MW wall-, cyclone-, and tangential-fired boilers originally designed for eastern coal and now firing PRB coals, selecting retrofit upgrades to various parts of the FDS, determining costs and the value of the ensuing benefits. The comparison of costs and benefits show surprisingly near-term breakeven costs of 1, 2 and less than 1 years, respectively for the wall-, cyclone-, and tangential-fired boilers.

 

Bob will be making a special recorded version of his presentation which we will post in the coming weeks. He was the other speaker also unable to communicate.

 

Roger Luoma, Manager of New Product Development for Stock Equipment Company, a member of the Schenck Process Group, made an impressive case for the use of gravimetric vs. volumetric feeders. There is a very substantial efficiency difference by providing consistent Btu input to the burners. The U.S. has installed a number of gravimetric feeders. Europe has been switching to them recently. Many new Chinese coal-fired power plants are utilizing the gravimetric feeders.

 

 

Bios, Abstracts and Photos can be seen at: BIOS, ABSTRACTS, PHOTOS - 6-13-13.htm

 

The individual presentations are as follows: