PRB Conference Program

In 2013, DTE investigated the potential benefits of Dynamic Classifiers to address constraints that limit the mills at the Monroe Power Plant, such as low primary air flow, significant pressure drop across the mill, fuel change impacts on mill performance, and the inability to operate at high load with certain fuel blends when a mill is out of service. Based on that analysis it was decided to install Dynamic Classifiers on seven mills of Unit 3. This presentation will detail the constraints that the plant is subject to that led to the execution of the classifier project. The presentation will also discuss the improvements offered by dynamic classifiers; including lower pressure drop across the mill, increased fuel production rate, reduced power consumption, and improved fineness values. It will touch on additional changes that were necessary, such as upgrading the mill seal air system and some electrical work. In addition to the technical considerations, this presentation will also outline the vetting process used by DTE to select a preferred equipment supplier. This presentation will include a summary of the results achieved after the classifiers have been in full operation and will review the lessons learned during the installation and commissioning process.

• Speaker
  • Dominic Martino, Senior Engineer Pulverizer\Gearbox SME, DTE Energy

Sunflower Electric – Holcomb Unit #1 is a 385 MW wall fired unit that was designed and erected to burn coal from the Powder River Basin. From the mid 1990’s forward the unit began running at full load and found that they were developing significant slag in the SH inlet, that was proving hard to clean when operating at load. Sunflower developed their own plan of load cycling and sootblowing when at lower loads, to try and keep the SH surface clean, but that wasn’t always enough.

In 2005 Sunflower elected to complete an upgrade of the furnace design that would help shield the SH inlet from radiant heat from the furnace, and in turn reduce flue gas temperature in to the SH. To accomplish this, the furnace arch was to be extended approximately 5 feet toward the front wall.

The design was completed and material was delivered to the site for installation in the spring of 2006 and the upgrades were completed in 2007.

Following installation of the new material, Sunflower experienced much less slagging and fouling when running at the same high loads using the same PRB coals. The operational improvements allowed them to run without having to schedule load reductions for ash shedding and cleaning.

• Speakers
  • Tom Dinkel, Generation Tech Services Supv, Sunflower Electric Power Corporation
  • Paul Reynolds, Sr. Manager, Sunflower Electric Power Corporation

Proper management of the boiler heat transfer surfaces is often neglected in power generation. This leads to suboptimal boiler performance which results in lower efficiencies, nonattainment of design steam temperatures, forced outages and shortened run times. Power plants are challenged to minimize the cost of operation while maximizing unit availability. Additionally, many utilities are varying their fuel supply for units not designed for this practice. In these cases, proper, responsive sootblowing becomes even more important. Optimization of sootblowing has become an important, low cost tool for increasing efficiency and maximizing unit output.

In today’s operating environment an increasing number of plant owners are implementing advanced systems for improved boiler performance that include optimizing combustion and reducing emissions. A natural complement is optimizing the boiler heating surfaces. Performance-based intelligent sootblowing provides power plants with a cost-effective method of achieving unit cleanliness and performance while reducing costs such as fuel usage, maintenance, and tube failures due to sootblower erosion. By targeting specific areas that have reduced heat transfer, sootblowing can be applied as needed to maintain unit performance. This is achieved using a unit-specific boiler heat transfer model to calculate real-time heat transfer efficiency for every heat trap component in the unit, including the furnace.

This presentation will show how Babcock & Wilcox’s Powerclean® intelligent sootblowing optimization system has been successfully implemented on units burning PRB coal to achieve maximum heat transfer efficiency to various boilers.

• Speakers
  • Mike Statler, Principal Performance Engineer, New Madrid Power Plant, AECI - Associated Electric Cooperative, Inc.
  • Jeremy Brown, Product Manager, Babcock & Wilcox

DTE Energy has commissioned an Intelligent Sootblowing (ISB) system on Monroe Station Unit 2 for controlling all of the boiler’s furnace wallblowers, and long retractable sootblowers. This supercritical unit burns between 50% and 100% PRB coal, (with the balance of coal being eastern US bituminous coal) and frequently changes the blend of coal which is fired within this range. Therefore, the ISB system is designed to accommodate these different blends. This presentation will discuss how the system is designed and some of the results of its use at Monroe Station.

• Speaker
  • James Musselman, Senior Production Engineer – I&C, DTE Energy

Continuous improvement in emission reductions requires evaluating contributions from every
source. One contributor, intelligent sootblowing (ISB), using boiler wall mounted
thermocouples, gas temperature sensors, and enthalpy calculations, has, for many years,
contributed to reduced NOx and CO emissions. A new, no non-sense approach, to furnace
ISB is challenging traditional methods and the frequent, but necessary, adjustments. Based on
the highly successful Griffin platform, a new ISB method evaluates the probability of furnace
cleanliness with consideration for slagging rate variation. Statistical methodologies are
employed, improving the decision of “where” to clean based on the probability of a clean
wall surface based on heat flux and elapsed time, as well as the decision “when” to clean
based on a slagging index driven by heat flux, FEGT, reheat spray flow, and unit load. For
one customer, this method resulted in a 73% reduction in water cleaning operations in the
furnace with an estimated savings of $560/day in fuel cost and a lower risk of water wall tube
rupture due to thermal cycling. The statistical approach reduces the dependence on arbitrary
set points and allows the system to easily adapt to dynamic boiler conditions and it's built on
an open platform that allows the plant engineers to easily tune the operation or even modify
the logic.

• Speakers
  • Tom W. Ziegler, Principle Performance Engineer, Ameren Missouri
  • Wade Baumgartner, President, Constrained Optimization, Inc.

Efficient and safe operation of any power plant requires that Operators have supreme confidence in the information being relayed to them. Some of the most critical pieces of information that an operator must process every day are the alarms that come in on the alarm summary. An alarm has to be valid, believable, and acted upon in a timely manner to prevent personnel injury, equipment damage, or loss of generation.

This presentation will highlight the steps, as part of an Alarm Management Strategy, that Westar has taken to build operator confidence and given them the ability to react in the correct manner. As well, some industry best practices will be discussed, including how to maintain a quality alarm system, once achieved.

• Speaker
  • Josh Newman, I&C/Electrical Maintenance Manager, Westar Energy

The variable demand for the production of electricity from fossil fueled power stations has compelled utilities to research and initiate unit layup operational best practices.
Luminant Energy has partnered with EPRI and a proprietary chemical provider in a R&D supplemental project that has established an optimal boiler layup process.
The new strategy also provides ultimate protection of the water and steam cycles of high pressure supercritical, subcritical, and HRSG combined cycle units as a continuous online treatment.
The presentation will highlight and summarize the reliability improvements observed on the Luminant units.

• Speaker
  • Keith Pearson, Retired Luminant Chemistry Manager, Chemistry Reliabilty Services, LLC