The following technical papers can be downloaded in portable document format (PDF) or can be ordered free of charge for delivery to you via mail.
BR#1885
Capacity Upgrade, Rehabilitation, NOx Reduction, and Efficiency Restoration (CO2 Reduction) of Suralaya Units 1 and 2 PT
Indonesia Power (a subsidiary of Perusahaan Listrik Negara [PLN], the State Electric Power Company), along with Marubeni Corporation of Japan and B&W PGG, have successfully upgraded aging power boilers at the Suralaya Power Station in Indonesia. The boilers for Unit Nos. 1 and 2 at Suralaya Power Station are 400 MW pulverized coal-fired Radiant Tower Boilers originally supplied by B&W and Marubeni in the early 1980s. The objective of this project was to extend the life of these units, increase steaming capacity, reduce nitrogen oxides (NOx) emissions, and restore unit efficiency-thus reducing the as-operating carbon dioxide (CO2) emissions. The project successfully met all of the objectives of PT. Indonesia and PLN.
BR#1861
The V-Temp™ Economizer System and Method for SCR Temperature Control
Emission requirements for fossil-fired boilers mandate that the boiler's air quality control system be capable of meeting emission standards from minimum load through full load. For optimum NOx reduction, the gas temperature entering the SCR must be maintained above the temperature at which ammonium bisulfate forms. The formation of ammonium bisulfate will degrade the SCR's NOx removal efficiency resulting in shorter catalyst life. The solutions currently available to resolve the EEGT issue do not provide the turndown required by most power plants. B&W PGG has patented the V-Temp™ system to control the flue gas temperature leaving the boiler and entering the SCR, within the SCR's desired operating load range. This paper will include results from successful installations of the V-Temp system on both supercritical and subcritical boilers.
BR#1822
Increasing the Combustion Capacity and the Performance of Existing Waste-to-Energy Plants
The amount of municipal solid waste is still increasing. An alternative solution to new waste-to-energy projects is an expansion and technical upgrade of existing incineration plants. This paper presents the basic ideas and principles used in upgrade projects. The core of the technology is a combination of a new furnace design, new water cooled wear zones and combustion grates, and new control systems. CFD modeling is an important tool in the design phase, and the paper gives a demonstration of the flow design process applied at B&W Vølund.
BR#1819
Use of Numerical Modeling to Compare Overfire Air Systems on Stoker-Fired Furnaces
The method by which air is introduced to a furnace is an important aspect of the combustion system. With the demands of more stringent regulations affecting modern combustion systems, numerical modeling has become a valuable tool for design and analysis. Numerical modeling has been used to compare a conventional overfire air (OFA) system design typically used on stoker-fired furnaces to a more advanced design. Modeling results demonstrate benefits of the advanced design.
BR#1810
COMO: A Computational Fluid Dynamics Model for Predicting Boiler Flow and Combustion
This paper describes a computational fluid dynamics and combustion model that simulates the numerous interacting processes that occur within a boiler burning pulverized coal and operating at steady state. The processes modeled include three-dimensional turbulent gas flow, particle motion, heterogeneous and homogeneous chemical reactions, and radiative and convective heat transfer. The model is routinely used as a cost-effective tool to assist in the design of boiler equipment and in the diagnosis and resolution of boiler operating problems. (1602K)
BR#1749
Boiler Structural Reinforcement Project at Belews Creek
This paper discusses the successful completion of a project to increase the air and flue gas path component structural integrity of Unit #1 at Duke Power's Belews Creek Station. (450K)
BR#1705
Reducing NOx Emissions in Tangentially-Fired Boilers – A New Approach
Power plant
owners and operators, especially those with coal-fired capacity, are facing
both significant opportunities and challenges. The move to deregulate the U.S.
power industry presents an opportunity for existing coal-fired power plants
because of their low fuel cost, and many are forecasting near-term growth of
this type of generation. The associated open market, however, will force all
power generators to control capital expenditures, reduce operating and
maintenance (O&M) costs, and maximize overall plant efficiency to remain
competitive.
At the same time, plant operators and owners are facing
the need to meet significantly tighter nitrogen oxides (NOx) regulations as a
result of the Clean Air Act Amendments (CAAA) of 1990. Lower NOx emissions
require both increased capital and operating costs that produce a negative
impact on overall plant efficiency. The winners in this race are those that
drive costs down by selecting technologies that meet the emissions requirements
at minimal capital and operating costs. Most technologies apply some type of
air staging, for the reduction of NOx emissions as required by the Title IV
Phases I and II of the CAAA with reasonable operating and capital costs. The
anticipated further reduction in NOx emissions levels as a result of Title I
(ozone non-attainment) requirements further increases the pressure on the
utility boiler owners and operators. Depending on where the final regulations
are set, the use of more costly technologies such as Selective Catalytic
Reduction (SCR) may be required.
At Duke Power Co., a building block
approach has been applied to the NOx strategy. In anticipation of more
stringent Title I regulations, Duke Power and B&W reworked the
tangentially-fired Marshall Unit 3 with a low NOx combustion system that will
maximize NOx reductions thereby minimizing the costs of future technology for
NOx control.
(548K)
BR#1653
Upgraded Superheaters Restore Lost Boiler Capacity
This paper discusses the successful replacement of aging power boiler superheaters with upgraded equipment to restore unit capacity at American Electric Power's (AEP) Clinch River plant. AEP and B&W attributed the success of this project to a cooperative partnership developed to execute the job. Benefits have been realized by AEP in the form of improved unit reliability, restored MW capacity, and lower than estimated costs, while B&W earned additional incentive-driven returns. (50K)
BR#1632
Partnering on a Utility Boiler Retrofit: Approach and Results
In 1993, Pacific Gas & Electric (PG&E) began the process of evaluating contracting options and selecting a contracting approach for use on its NOx retrofit program, which had the goal of achieving significant reductions in emissions from its gas and oil fired units. PG&E determined that partnering was the preferred method, based on its greater potential for improved quality, risk identification and management, and cost control. This paper discusses the approach used to implement this partnering project. (90K)
BR#1622
Low NOx Combustion System With DSVS Rotating Classifier Retrofit for a 630 MWe Cell Burner Unit
New England Power Company’s (NEP) 630 MWe Brayton Point Unit 3 is a universal pressure (UP) type supercritical boiler originally equipped with pulverized coal (PC) fired cell burners. In order to comply with the Phase I NOx emissions requirements under Title I of the 1990 Clean Air Act Amendments, the unit has been retrofitted with a low NOx staged combustion system during the Spring 1995 outage. The unit was restarted in early May 1995 and was operating under the State Compliance emission levels by the end of the month. Additional optimization testing was performed in August, 1995. This paper describes the project and discusses the retrofit emissions data and concludes with recommendations for retrofitting other similarly designed units. (186K)
BR#1621
Improved Method of Chromizing Waterwall Panels for Corrosion Protection in Low NOx Utility Boilers
Corrosive attack by sulfidation has been a long-standing concern in coal-fired utility boiler waterwall panels. Many units that have converted their burner technology to meet NOx requirements of the 1990 Clean Air Act Amendments (Phase 1) have experienced more aggressive attack due to the change in stoichiometric conditions. Furnace wall tubes situated near burner openings with deep staging have shown wastage rates of 60 mils per year and higher. One method that is gaining increased acceptance as a life extension treatment for waterwall panels is chromizing. Chromizing is a process by which chromium is diffused into the tube surface base metal to form a chromium-rich layer typically 10-15 mils thick. Inherent in this process, however, is the formation of decarburization under the diffusion layer. If the amount of decarburization created is excessive, tube strength is significantly reduced. This paper will describe an improved process that achieves the required chromizing depths while limiting the decarburization layer. (393K)
BR#1616
Upgrades and Enhancements for Competitive Coal-Fired Boiler Systems
Deregulation of the electric utility industry is resulting in significant opportunities and challenges for U.S. power generators. Existing coal-fired capacity potentially offers the lowest variable cost power production option if these units are upgraded to optimize capacity, operating cost (including fuel), efficiency, and availability while also meeting today’s stringent emissions control requirements. This paper highlights a variety of boiler system upgrades and enhancements which are being utilized to make aging coal-fired boilers low cost competitors in the 1990s. (177K)
BR#1598
Operational Results of a Low NOx Burner Retrofit on a 780 MW PC-Fired Utility Boiler
Title I of the 1990 U.S. Clean Air Act Amendments requires that states develop and implement a Reasonably Available Control Technologies (RACT) emissions control program. The Pennsylvania Department of Environmental Protection (PaDEP) has developed such a program. This program states that industrial, commercial and institutional boilers with greater than 100 x 106 Btu/hr heat input must install low NOx burners with separated overfire air (OFA), unless it can be shown technically infeasible or excessively cost prohibitive. Installing low NOx burners and separated overfire air on Bruce Mansfield Units 1 & 2 was technically feasible and, by the standards set by the PaDEP, was cost effective. The primary objectives of this boiler retrofit were to comply with PaDEP requirements. Additional goals of the project included: to ensure no negative impact on unit operations and availability; to minimize increases in unburned carbon; to minimize the impact on plant operating, maintenance and future capital budgets; and to position the plant to meet future state and federal clean air act requirements. (77K)
BR#1597
Challenges of Retrofitting Low NOx Combustion Technology to a Single Wall Fired Boiler
PECO Energy's Cromby Unit #1 is a 160 MW single wall fired, coal and oil fueled boiler that is representative of 250 boilers across the United States. Although the techniques had been demonstrated elsewhere individually, Cromby was B&W's first single wall fired retrofit using new low NOx burners and side wall ports in conjunc-tion with overfire air ports. This paper will describe the equipment as well as the numerical modeling techniques used to optimize performance. The paper will also discuss the effects of low NOx burners on the boiler and balance of plant equipment, with specific emphasis on the changes in flyash characteristics and the resultant impact on precipitators. (sssK)
BR#1589
Control System Retrofits to Improve Plant Efficiency
The availability of powerful first principle type models designed for PC-based computer hardware provides a simple and effective tool for the study of transients within power plants. All essential components of the plant including the controls can be modeled and the behavior of the plant to various transients evaluated. This paper addresses the use of such a dynamic model to design an improved control strategy for pulverized coal fired drum type boilers connected to single reheat type turbine generators. Comparisons with the current techniques is used to quantify the benefits and demonstrate the simplicity of the control methodology. (93K)
BR#1584
A Coordinated Approach to Control System Modifications
This paper describes the structured approach to a major control system retrofit. The project included replacing outdated controls hardware with a distributed control system as part of a low NOx conversion project. (80K)
