Budgetary Proposal P006876 – Revision 4 

to 

AEP SWEPCO 

for 

Flint Creek Unit 1 

Low NOx Combustion System 

submitted by: 

June 20, 2013 

This document is the property of Babcock & Wilcox Power Generation Group, Inc. (B&W) and 

is acceptable for distribution by AEP solely to United States Federal and/or State regulatory 

agencies, upon their request, for the sole purpose of considering environmental permitting 

issues as related to AEP SWEPCO’s Flint Creek Station, Unit 1. 

 2013 BABCOCK & WILCOX COMPANY POWER GENERATION GROUP, INC.

ALL RIGHTS RESERVED.
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Table of Contents Page TC-1 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

TABLE OF CONTENTS 

Introduction .................................................................................................................. 1 

Technical Discussion ................................................................................................... 2 

Scope of Supply........................................................................................................... 3 

Not Used ...................................................................................................................... 4 

Schedule ...................................................................................................................... 5 

Expected Performance ................................................................................................ 6 

DRB-4ZTM Experience List ........................................................................... Appendix A 

AireJetTM Burner Experience List ................................................................. Appendix B 

DRB-4ZTM and XCL Reference List ............................................................. Appendix C 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 1 Page 1-1 

Introduction 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

1. INTRODUCTION 

The following Budgetary Proposal, P006876, is submitted to AEP SWEPCO in 

response to your request. 

The purpose of this Budgetary Proposal is to provide engineering, material, fabrication 

and delivery for the application of AireJetTM or DRB-4Z burners and OFA at Flint 

Creek Unit 1, which is B&W unit RB-528. 

This Budgetary Proposal is being submitted by Babcock & Wilcox Power Generation 

Group, Inc. (B&W) which has its home offices in Barberton, Ohio USA. B&W is a full 

scope supplier of steam generating equipment and accessories to the Industrial and 

Utility industry. Babcock & Wilcox Power Generation Group, Inc. has over 140 years 

of experience in the supply of materials and highly engineered products as well as 

current state of the art technology. 

Babcock & Wilcox Power Generation Group, Inc. wishes to thank AEP SWEPCO for 

the opportunity to submit this Budgetary Proposal and to assure you that should this 

Budgetary Proposal result in a Contract, the Contract will be executed in accordance 

with industry standards of good engineering practice, fabricated, and delivered in a 

timely manner. The scope of supply, pricing and terms proposed are as stated in this 

Budgetary Proposal. 

Points of contact for questions and/or additional information are as follows: 

Jim Graves 

District Sales Manager 

Dallas, Texas 

Phone: (972) 772-6011 

jkgraves@babcock.com

Mark Zeiger 

District Sales Manager 

Cincinnati, Ohio 

Phone: (513) 326-4362 

mazeiger@babcock.com

Kevin Thomas 

Proposal Manager – Comb. Systems 

Barberton, Ohio 

Phone: (330) 860-2038 

krthomas@babcock.com

Denis Osowski 

Regional Service Projects Manager 

Barberton, Ohio 

Phone: (330) 860-1787 

dmosowski@babcock.com

Brian Benz 

Project Manager 

Barberton, Ohio 

Phone: (330) 860-6290 

brbenz@babcock.com
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-1 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

2. TECHNICAL DISCUSSION 

In response to AEP SWEPCO’s request for low NOx combustion modifications, B&W 

has provided two options for a staged combustion design which employs B&W’s 

AireJetTM low NOx burners or DRB-4ZTM burners in combination with the addition of 

Overfire Air (OFA). 

B&W AireJetTM Burner 

Previously, low NOx pc-fired burners were designed to carefully regulate the rate of 

combustion in order to limit peak temperatures (thermal NOx), and limit oxygen 

availability to the origin of the flame (to limit fuel NOx). Over Fire Air (OFA) was then 

added to the system to further reduce NOx emissions. The B&W DRB-4ZTM burner 

was designed according to these fundamental principles. 

However, the AireJetTM Burner is fundamentally different. It is the culmination of an 

extensive research and development program directed at reducing emissions during 

the combustion process. From inception, this technology integrates the use of air 

staging (OFA), a concept first conceived and patented by Ralph M. Hardgrove of The 

Babcock & Wilcox Co. 

Air staging is used to reduce the burner zone below theoretical air requirements, that 

is, to an air/fuel stoichiometry less than 1.0. The purpose of the burner then changes 

with a goal of accelerating the combustion process. Accelerating combustion under 

air staged, fuel rich conditions quickly generates an oxygen deficiency, producing 

hydrocarbons which prevent oxidation of nitrogen, and decompose NOx formed 

earlier in the earliest portion of the flame (which is unavoidably air rich). Accelerating 

combustion in a unique way not only reduces the NOx emissions, but reduces the 

need for excess air. 

 

The AireJetTM Burner is uniquely formed around an air jet along the center axis of the 

burner. Extensive computer modeling and research revealed that supplying air to the 

root of the flame, in proper proportion and by proper means, will greatly intensify 

combustion at this point. Pulverized coal is ignited in the furnace by interaction with 

hot secondary air. The rate of ignition is limited by the “wetted surface” of the fuel jet, 

that is, the boundary which interfaces with secondary air. Inclusion of an air jet in the 

center of the flame requires the fuel nozzle to expand to a larger diameter to enclose 

this. The center air, or core air, provides a large boundary area to contact the interior 

portion of the fuel jet. In addition, the fuel nozzle diameter is expanded to provide a 

further increase in air/fuel boundary at the outer periphery of the fuel jet. Combined, 

the ignition surfaces are more than doubled with this approach. Rapid ignition by the 

AireJetTM burner translates to an extraordinarily stable flame over a wide range of 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-2 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

conditions, including reduced firing rates, uncharacteristic of many slow mix low NOx 

burners (LNB’s). 

Outside Ignition

Layer

Air Rich

Outer Layer

High

Intensity

Combustion

Fuel Rich

NOx Reduction

Inside Ignition

Layer Secondary Air

Secondary Air

Pulverized Coal

and Primary Air

B&W AireJet® Burner

“Inside Out / Outside In” Combustion

• Core air matched to coal properties

• Rapid, stable ignition

• Accelerate rate of combustion—bellows effect

• Fuel rich longer = much lower NOx

• Cleaner burning= lower XS air, higher efficiency

Rapid ignition is only the first step. The next step is to supply additional oxidant (air) 

to the center of the AireJetTM burner flame. In proper proportion, this air feeds ignition 

and greatly accelerates combustion (like a bellows) and generates high temperatures 

in the root of the flame. The high temperatures in the flame root actually cause more 

of the coal particle mass to gasify, or devolatize, and these gases also proceed to 

quickly burn. The coal burns more rapidly, leaving less char for final burnout 

reactions. In the process, oxygen is quickly consumed producing a highly fuel rich 

flame core. Resultant hydrocarbons then reduce NOx formed in the earliest stage of 

the flame, and prevent further NOx formation downstream. 

The two secondary air streams which outwardly surround the fuel jet act in concert to 

produce a large IRZ (internal recirculation zone). These cause combustion products 

at the outer periphery of the flame to be recirculated into the fuel rich center for 

destruction of NOx. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-3 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

• .

Core Air Inlet

Duct

Core  Damper

Actuator

Sleeve Damper

Actuator

Coal + Primary Air Inlet

Ceramic Lined Nozzle

And Core Components Sleeve Damper

Pitot Grid

Outer Spin

Vanes

Inner Spin

Vanes

Burner Support

System

AireJet® Burner

Rapid combustion with the AireJetTM burner results in cleaner combustion, as the fuel 

burns much more thoroughly from the inside out, as well as from the outside in. Much 

lower CO emissions result, which enables operation with less excess air. Lower 

excess air increases boiler efficiency and reduces fuel consumption. Low excess air 

also provides even lower NOx emissions. 

The AireJetTM Burner is designed to match the center air flow rate to the coal(s) fired, 

in order to maximize combustion close in to the burner. The center air is drawn from 

inside the burner windbox compartment. Each burner is equipped with a damper to 

adjust the flow of air to the center of the flame (core air). The core is ducted to a 

center chamber and tube formed within an expanded coal nozzle. The interior of the 

coal nozzle and exterior of the core assembly are lined with ceramics for long wear 

life. The tips and other front end portions of the burner are high quality stainless steel 

(309H) for excellent temperature resistance and extended wear. Secondary air is 

supplied to the dual air zone burner air assembly, and regulated by an adjustable 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-4 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

slide damper. These air “register” assemblies share the mechanical integrity and 

heavy-duty shop-assembled construction of B&W’s well proven DRB-4ZTM burners. 

 

An Advanced Over Fire Air System is integrated with the AireJetTM burners. The 

rugged, adjustable Dual Zone NOx ports supply the remaining air (OFA) necessary to 

complete combustion. Correct separation between the OFA system and burners 

provides time for more NOx reduction, and provides more complete char burnout 

ahead of the OFA system. 

 

B&W’s AireJetTM Burner, in combination with 

Advanced Over Fire Air, achieves much 

lower NOx with lower CO and with lower 

excess air than other low NOx burners. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-5 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

The DRB-4ZTM Burner 

The DRB-4ZTM was conceptually developed using proprietary computational fluid 

dynamic computer modeling. Modeling uncovered the advantages of an additional air 

zone surrounding the burner nozzle in order to better control critical aspects of mixing 

around the core of the flame. A prototype burner was then designed, constructed, 

and refined through an extensive program of large-scale combustion tests. The tests 

were performed in B&W's state-of-the-art Clean Environment Development Facility 

(CEDF) in Alliance, Ohio. Ultimately, the DRB-4Z reduced NOx significantly beyond 

our most advanced dual zone low NOx burner. These reductions were accomplished 

on sub-bituminous (PRB) and several bituminous coals. 

The advanced DRB-4Z burner is designed to produce very low NOx emissions by 

means of a transition zone that interfaces between the central oxygen-lean zone and 

the secondary combustion air. 

The transition zone acts as a buffer between the fuel rich flame core and the 

secondary air streams. The flow field produced by the transition zone draws gases 

from the outer portions of the flame inward toward the flame core. NOx formed in the 

oxygen-rich outer flame region is reduced back to other nitrogenous species in the 

process. This results in significantly lower NOx emissions than what is achieved by 

dual zone low NOx burners. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-6 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

The mechanical design of the DRB-4Z draws heavily on the DRB-XCL burner, which 

has demonstrated excellent reliability in the severe conditions prevalent in utility boiler 

service. Adjustable vanes provide on-line tuning capability, in a well-proven design. 

Each burner has air flow controlled by an adjustable slide damper, with relative air 

flow measurement provided by a multi-point pitot grid. The burner is shop assembled 

in one unit which is ready to install, using the mounting hardware provided. A burner 

slide rail system consisting of supporting rectangular tubing, bridging windbox steel, 

and saddle supports is provide for each burner such that the entire burner load is 

transferred directly to the windbox steel and furnace waterwalls. This support system 

insures that the burner can accommodate expected thermal expansions without 

distortion of the waterwalls or windbox casing. 

These burners are constructed with heavy, high quality stainless steel plate combined 

with a system of stiffeners to maintain structural integrity at high temperatures. 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-7 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

The proposed DRB-4Z Burner includes many specific design features assuring long 

term reliability with minimal maintenance. This design avoids the use of the scroll 

burner inlet, flame holder device (flame stabilization ring), or complex coal nozzle exit 

geometry which are often prone to erosion, initiation of coal nozzle fires, coking and 

overheat distortion. 

DRB-4Z Burner 

Mechanical Features
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-8 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

B&W Dual Air Zone Overfire Air (NOx) Port

Dual zone NOx ports and associated sliding dampers, spin vanes and air monitors are 

proposed to supply secondary air to the furnace to complete the two-stage 

combustion process, and optimally lower NOx emissions. 

Optimum over fire air mixing characteristics can be achieved with the Dual Zone NOx 

Port through its independent control of total air flow, air swirl, and air split between the 

penetration inner zone and variable swirl outer zone. 

Each Dual Zone NOx Port will be equipped with an automated linear actuator, which 

regulates a control rod that extends through the cover plate and ties to the total air 

flow damper. Regulation of this drive and damper will control the air flow to the port 

and thus allow for the adjustment of the burner zone stoichiometry as well as optimal 

air flow balancing between the ports. Similar to the DRB-4ZTM Burner design, pitot 

grid air flow measurement devices are supplied on each port for relative air flow 

indication. 

Spin vanes, located in the outer air zone of each Dual Zone NOx Port, can be 

adjusted to control the swirl of air from the port. Imparting more tangential velocity, or 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-9 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

swirl, will flare the air flow pattern and provide less penetration. This results in 

improved air flow mixing with furnace gases along the furnace side walls. 

In addition, a biasing damper can be set to vary the air flow split between the inner 

and outer zones. Thus, air swirl can be adjusted without affecting the air flow split 

between these zones. Optimization of penetration, swirl, and biasing settings of the 

Dual Zone NOx Ports will be done during unit commissioning. 

The Dual Zone NOx Port shares many of the rugged design features of the DRB-4ZTM

and DRB-XCL Burner. These similar features include: stainless steel sleeves and 

spin vanes, moment arm lever spin vane adjustment, longitudinal stiffeners, rugged 

control rod design and support design. 

Combustion System Design 

The successful application of a staged low NOx combustion system (burner system 

with overfire air) to an existing coal fired boiler generally requires a tailored approach 

to each specific application. Variations in primary furnace geometries, extended heat 

transfer surface arrangements, furnace temperature profiles, coal fuel properties, coal 

pipe distribution, burner design, and external obstructions greatly influences the 

overall design approach of any retrofit low NOx combustion system. These same 

variables also greatly impact the ultimate NOx/CO reduction potential. 

Maximizing in-furnace NOx reductions requires careful coordination and design of a 

complete burner system which includes low NOx burners, overfire air ports, balanced 

fuel, and good primary and secondary air distribution. The AireJetTM and DRB-4Z 

burners are specifically designed to operate deficient of the required combustion air to 

complete the combustion process (sub-stoichiometric). The overfire air system then 

provides the balance of the combustion air to complete combustion prior to exiting the 

primary furnace. 

Several design principles govern the overall OFA System design. These include 

vertical placement(s) of the OFA ports, the quantity of secondary air diverted to the 

OFA system (design bulk stoichiometry), the arrangement of the OFA ports within the 

furnace envelope, and the functional characteristics of OFA ports themselves. 

Fundamentally, deeper staging with longer residence time under fuel rich conditions 

most effectively reduces NOx emissions. Consequently, a key factor is the residence 

time available in the furnace. This is a function of the furnace size, fuel input, air flow 

rate, and flue gas density. The furnace shaft above the burners and ahead of the 

OFA ports provides residence time under fuel rich conditions to reduce NOx 

emissions. The furnace shaft beyond the OFA ports provides residence time to 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-10 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

complete mixing and combustion before entering the convection pass. The vertical 

placement of the OFA ports is therefore critical to both NOx reduction and overall 

combustion efficiency (CO and unburned carbon). Ports placed too close to the 

burner zone will impair NOx reduction performance. Ports placed too close to the 

furnace exit can result in elevated levels of CO and unburned carbon, increased 

slagging in the superheater and reheater, and shifts in furnace exit gas temperature. 

The quantity of secondary air provided to the OFA system is also a key factor. NOx 

as a function of burner zone stoichiometry reaches a minimum as a function of coal 

properties, burner design, and residence time. Overall, the proposed OFA system is 

designed to divert enough secondary air away from the burners to achieve a these 

stoichiometries at MCR conditions. The quantity of OFA influences not only the NOx 

performance but the mixing capability of OFA in the upper furnace. 

The number, arrangement, and sizing of the of OFA ports for a given applications is 

based on the furnace gas to OFA mass flux ratios, drift/penetration criteria, minimum 

horizontal coverage criteria, and the burner firing pattern. The sizing, included 

functionality, and arrangement of the individual OFA ports are designed to provide 

necessary and sufficient mixing to achieve uniform flue gas species, temperature 

profiles, and complete the combustion process prior to reaching the furnace exit. 

B&W primarily uses our Dual Zone NOx Port design in staged combustion system 

applications. The functional design features of Dual Zone NOx ports mentioned 

above provide the flexibility to achieve optimum over fire air mixing characteristics 

with the ability to independently control total air flow, air swirl, and air split between 

the penetration inner zone and variable swirl outer zone. Imparting more tangential 

velocity, or swirl with the adjustable spin vanes will flare the air flow pattern while 

providing less penetration. Alternatively, biasing air towards the ports inner core zone 

increases penetration and mixing towards the center of the furnace. The ability to 

optimize the mixing characteristics of the OFA with the online adjustable features of 

the B&W Dual Zone NOx Port helps to ensure optimal site specific emissions 

performance. 

B&W’s design standards governing all of the principles above have been developed 

utilizing a combination of lab scale testing, full furnace CFD Modeling, and empirical 

field data collect from over 150 low NOx combustion applications. 

AireJetTM or DRB-4Z burners combined with an advanced OFA system using Dual 

Zone NOx ports provide the means to achieve minimum emissions of NOx and 

unburned combustibles. Adjustable components within the burners and NOx ports 

enable tuning to optimize performance given site specific variations in flows and 

conditions. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-11 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Site Specific Considerations and Solutions 

The Unit 1 boiler at the Flint Creek Generating Station is an opposed-wall coal-fired 

unit (RB-528) designed by the Babcock & Wilcox Company (B&W). The boiler is a 

duplicate to RB-514, RB-529 and RB-571 (Welsh Units 1-3, respectively). The boiler 

has a nominal rating of 550 MWe, with a combustion system consisting of 42 dual 

register burners, arranged as 7 columns by 3 rows on both the front wall and the rear 

wall. There are no existing OFA ports. 

B&W can offer a choice between a low-NOx combustion system which consists of 42 

AireJetTM burners or 42 DRB-4Z burners. In each case, B&W proposes 12 dual-zone 

NOx ports to upgrade the existing combustion system. Ports near the sidewalls are 

expected to be slightly larger than those on the inner columns to assure good air 

coverage along the sidewalls where we have found that high concentrations of CO 

can exist. 

COMOSM modeling software will be used to evaluate the performance of the proposed 

combustion system and examine different configurations of the OFA ports in order to 

optimize combustion performance. Performance will be evaluated by comparing gas 

temperature, carbon monoxide concentration and oxygen concentration distributions 

throughout the furnace. 

Six (6) B&W 89 pulverizers each supply coal to seven burners. The unit is equipped 

with compartmented windboxes wherein the burners associated with each pulverizer 

are separated into their own windbox compartment. Secondary air for each 

compartment is measured by airfoils (original equipment), and regulated with 

automated dampers at each compartment entrance, as a function of coal feed rate to 

the respective pulverizer. Each compartment is fed from each end. The original 

burners are 44” diameter Dual Registers. 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-12 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

All of the new AireJetTM and DRB-4Z burners will be located at the existing burner 

locations. Either of the new burners will also be included with ceramic throat tiles to 

reduce the existing throat diameter. 

As part of the base bid, B&W has included an engineering analysis of the complete 

PC piping system to provide a relative balance of coal flows between the coal pipes 

common to each pulverizer. This approach includes theoretical resistance 

calculations on each individual burner line. Ceramic lined, flanged venturi type 

resistor sleeves (orifices) are then sized and applied to balance each theoretical line 

resistance within a common mill to within +/-2.5%. The specific number of required 

resistor sleeves is not known until the analysis is complete. 

OFA and Duct System Design 

While the future OFA compartment and feeder elbows are already in place, the 

proposed OFA system is designed with windbox extensions to enclose the NOx ports 

above the top level of burners. The existing air foils in the future OFA compartment 

will need to be removed, and turning vanes and a new airflow monitoring system will 

be installed. 

FPS Equipment 

Included in the base price of this proposal will be the supply of new FPS ignitors, 

ignitor scanners, main flame scanners, and blower skids. It is assumed that the 

current valve racks can be used, however, during the contract phase it could be 

determined that the existing valve racks may not be suitable. 

B&W Modeling Services 

Within the fossil power generation industry, B&W has a unique capability in 

computational fluid dynamics (CFD) and combustion modeling. The substantial 

investment in computational modeling made by B&W over the past twenty-five years 

has culminated in COMOSM, our proprietary flow and combustion model. COMO uses 

an unstructured mesh with a mixture of element shapes for greater geometric 

flexibility, and adaptive mesh refinement to control resolution in regions of high 

gradients (e.g. turbulent jets, diffusion flames, etc.). It includes advanced capabilities 

for simulating turbulent flow, energy and radiation, heterogeneous reactions, particles, 

surface reactions, gas phase reactions, and tube banks. COMO includes advanced 

sub-models for coal devolatilization, char burning and fuel-nitrogen release. Gas 

phase chemical kinetics are simulated with any number of species and reactions, 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-13 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

using established reaction mechanisms, and including the effect of turbulence on 

kinetic rates. 

COMO has been used routinely at B&W for over a decade to improve the design and 

operation of boilers and boiler components. A wide variety of boilers have been 

modeled, including wall-fired, tangentially-fired, downshot, cyclone, recovery, and 

stoker. The boiler components modeled have included air-heaters, burners, NOx 

ports, sorbent injection systems, windboxes, selective catalytic reduction systems, 

flue work, and convection passes. The diverse capabilities of COMO have been 

proven through unique applications in coal gasification, coal and natural gas 

reburning, and off-gas combustion from steel smelters. 

When modeling a boiler, the geometry is carefully depicted using a collection of 

control volumes (also called a computational grid or mesh), such as is shown in 

Figure 1 for a wall-fired unit. Fundamental conservation principles (conservation of 

mass, momentum, and energy) are then applied to each of these control volumes, 

resulting in a coupled set of governing equations that are subsequently solved on 

high-speed computer processors to predict steady-state furnace performance. This 

model is augmented with empirical data such as rate parameters for coal pyrolysis, 

coal devolatilization and char oxidation, wall and tube bank heat transfer 

conductance, and pressure loss coefficients for the tube banks. These parameters, as 

well as the ultimate analysis of the coal and the furnace operating conditions, are 

used as inputs to the COMO model. More specifically, burners and OFA ports are 

included in the model as flow inlets to the furnace at the appropriate wall locations. 

Swirl is added to the burner and OFA port flows consistent with specified vane 

settings. 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-14 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

A sample of static graphical output is shown in Figures 2 and 3. Those figures 

show contours of gas temperature and carbon monoxide concentration, 

respectively, for a 600-MW coal-fired boiler. 

 

Computational Mesh on Boiler Surface 

Full Mesh and Enlarged View of Selected Burner and OFA Port Inlets 

600 MW wall-fired pulverized-coal boiler 

Mesh in middle burner region 

Mesh in OFA port region 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-15 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Numerical modeling predictions of a 600 MW wall-fired 

pulverized-coal boiler: contours of gas temperature. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-16 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

 

Numerical modeling predictions of a 600 MW wall-fired pulverizedcoal boiler: contours of carbon monoxide concentration. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-17 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Option A: B&W FocalPointTM Optimization System

In addition to our base proposal, Babcock & Wilcox Power Generation Group, Inc 

(B&W) recommends B&W’s FocalPointTM Optimization System to enhance combustion 

system performance. The FocalPoint system is a real-time, closed-loop system that 

leverages B&W’s combustion system design experience to continuously control CO 

and NOx emissions. 

The proposed system will include B&W’s FocalPointTM advanced optimization 

software, an O2/CO emissions grid for the convection pass of the boiler, and 

automation of the core air zone of the OFA ports. The FocalPoint system will be 

configured with proven optimization strategies designed specifically for improved CO 

and NOx control using B&W’s dual-zone OFA ports. 

The FocalPoint system is currently used at AEP Welsh 3 for combustion 

optimization to control NOx and CO emissions as well as Reheat Outlet 

Temperatures. 

System Description

B&W’s experience has been that optimal low NOx operation is achieved through 

effective mitigation of CO emissions that accompany low NOx combustion. Further, it 

has been proven that proper continuous adjustment of B&W’s dual-zone OFA port 

maintains reduced CO and NOx emissions through varying operating conditions. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-18 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Figure 1 FocalPoint Optimization System 

Figure 1 illustrates how the FocalPoint system integrates with the DCS to provide 

advanced supervisory control. The FocalPoint system includes twelve (12) O2 and 

CO probes – one for each OFA port – to provide emissions information that can be 

tied to each OFA port. The FocalPoint software uses this information, in coordination 

with its optimization strategies, to pinpoint the most effective response to control CO 

and NOx emissions. The system then adjusts the air distribution at the OFA ports to 

maintain low CO and NOx emissions for the current conditions. 

The optimization strategies utilized by the FocalPoint system are designed for 

effectiveness in all operating conditions. This ensures that CO and NOx emissions 

are minimized throughout the entire load range and in all mill configurations. 

FocalPoint Advanced Optimization Software

The FocalPoint software features numerous models, functions, and algorithms that 

may be customized for any optimization problem. Key to the system is the intuitive 

graphical analysis and logic development environment, as shown in Figure 2. The 

FocalPoint system can function as an advisory or a supervisory system with the mode 

of operation being selectable by operations personnel. When employed as part of a 

combustion optimization system, the FocalPoint program includes advanced 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-19 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

combustion control algorithms developed from B&W Research and Development and 

field experience. When in supervisory mode, FocalPoint typically effects changes in 

operations by influencing the biases associated with particular DCS control loops. In 

open-loop mode, FocalPoint provides the operator with information on the best 

settings for control biases of the same DCS control loops. 

Figure 2 FocalPoint Analysis and Logic Development Environment 

An example of the effectiveness of the FocalPoint Optimization System in closed-loop 

mode is shown in Figure 3 below. The system continuously works to reduce the 

absolute NOx and CO emissions so that optimal combustion can be achieved for the 

current operating conditions. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-20 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Figure 3 Results of FocalPoint Control of CO Emissions 

Commissioning

These services comprise the effort necessary to commission the FocalPoint system 

once the burners have been tuned by B&W. It includes on-site service to assist with 

the installation and start up of the FocalPoint system and conduct training. The 

FocalPoint training consists of classroom training as well as hands-on training. 

Software Maintenance

The FocalPoint Software Program is continually updated to include new features and 

capabilities. For example, new strategies and algorithms are frequently added into 

the FocalPoint software. Software Maintenance permits the user to receive all 

software program updates and upgrades. In order for the customer to receive these 

upgrades in a timely fashion, VPN access to the installed FocalPoint system is 

strongly suggested. The first year of software maintenance is included in the system 

price. 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-21 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Engineering Support

Engineering Support provides the user with remote technical support for the 

FocalPoint system. For this service to be most effective, VPN access to the installed 

FocalPoint system is needed. The first year of engineering support is included in the 

system price. 

Scope of Supply

The specific scope of supply for the FocalPoint system for this project includes: 

Twelve (12) ABB SMA O2 & CO Smart Analyzers which will be installed in the 

vertical convection pass to provide O2 and CO emissions information to the 

combustion optimization system. DCS programming to incorporate the analyzers into 

the DCS is not included. 

Twelve (12) Beck Linear Drives to automate the core air zone of the OFA ports. 

Mounting hardware will also be supplied with the drives. DCS programming to 

incorporate the drives into the DCS is not included. 

One (1) FocalPoint Advanced Optimization Software to analyze combustion and 

implement advanced control to maintain low CO and NOx emissions. The FocalPoint 

software operates on a Windows-based server that is supplied with the optimization 

system. The FocalPoint system also uses industry standard communications 

protocols like OPC and Modbus for integration with the DCS. 

Engineering Services for installation support and startup of the system. 

Installation Arrangement Drawings will be provided for the analyzers and drives to 

support the equipment installation. Mechanical and electrical installation of the 

system is not included. 

FocalPoint Software Maintenance – The FocalPoint Software program is continually 

updated to include new features and capabilities. FocalPoint Software Maintenance 

permits the user to receive all software program updates and upgrades. FocalPoint 

Software Maintenance is made easier with VPN access to the installed FocalPoint 

system which allows B&W to install updates and upgrades remotely. However, VPN 

access is not required. The first year of software maintenance is included in the 

system price.

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 2 Page 2-22 

Technical Discussion 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

FocalPoint Engineering Support - Engineering Support provides the user with 

remote technical support for the FocalPoint system. Engineering Support is facilitated 

with VPN access to the installed system but it is not required. The first year of 

engineering support is included in the system price. FocalPoint Engineering Support 

includes: 

 Troubleshooting over the phone and via the VPN connection, if available 

 Email contact support 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-1 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

3. SCOPE OF SUPPLY 

Section 2, Technical Discussion, described the modifications that B&W proposes for 

Flint Creek Unit 1. Following is the Scope of Supply listing that further defines B&W’s 

offer. Equipment and/or services not included in this scope of supply listing are not 

included in this proposal offering. Please refer to the terminal points listing, and other 

information in this proposal for further clarification of the proposed scope. 

Item 1: Ultra Low NOx AireJetTM Burners 

Qty 42 – B&W, AireJetTM, Low NOx burners equipped for coal firing. 

 Each burner to include: 

 Externally adjustable outer air zone spin vanes 

 Burner sliding air disk manual ratchet drive 

 Pitot tube relative air flow measuring device with magnehelic gage 

 Provisions to accept new FPS Oil Ignitors 

 Provisions to accept new FPS flame scanners 

 Three Type K permanent thermocouples to monitor coal nozzle and 

burner outer sleeve temperature with common junction box shop 

mounted on burner coverplate 

 Field insulated burner coverplate 

 Burner support rails and attachment hardware 

 Ceramic throat tile assemblies to reduce existing furnace waterwall 

openings 

 Manual rotary handles for core air butterfly dampers 

 Segmented, ceramic lined coal elbow with removable back 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-2 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

1 Lot – Burner line resistor sleeve engineering analysis to identify number and 

sizing of resistor sleeves. Each required resistor sleeve includes flanges, 

nuts, bolts, washers and gaskets. Pricing supplied in Section 4 will be per 

resister sleeve – the exact quantity (up to 36) will be determined during the 

contract phase. 

Qty 12 – Dual Zone OFA Ports 

 

 Each OFA port to include: 

 Barrel assembly with pitot tube relative air flow measuring device 

 Externally adjustable outer air zone spin vanes 

 Manually adjustable biasing damper for adjustment of the air flow split 

between the inner and outer zones 

 Total air flow control damper with Beck linear drive 

 Field insulated cover plate 

 Slip seal ring for attachment and seal to the furnace wall 

 Two, Type K permanent thermocouples to monitor core air sleeve and 

port outer sleeve temperature with common shop mounted 

thermocouple junction box 

 Four - Mass Air flow measurement equipment for each OFA windbox 

feeder duct. Pitot grid type device to be supplied with integral 

temperature measurement for direct output of mass air flow. 

 Dual Zone NOx Port support rails and attachment hardware 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-3 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Qty 2 – New OFA windbox extension, one on the front furnace wall and one on the 

rear furnace wall, supplied to house the new OFA Ports and convey 

secondary air to the new OFA port inlets. Each extension will be constructed 

with an internal support steel structure with casing and stiffeners and 

designed for current NFPA internal pressure requirements and be compatible 

with new boiler pressure increase requirements. 

Item 2 – Low NOx DRB-4ZTM Burners 

Qty 42 – DRB-4Z Burner Assemblies (Plug-In) low NOx burners equipped for coal firing.

Each burner to include: 

 Externally adjustable outer air zone spin vanes 

 Externally adjustable transition zone damper 

 Burner sliding air disk manual ratchet drive 

 Pitot tube relative air flow measuring device with magnehelic gage 

 Ceramic lined coal nozzle, with alloy tip 

 Ceramic lined coal elbow 

 Coal nozzle diffuser and deflector fabricated from silicon carbide wear 

material 

 Provisions to accept new FPS Oil Ignitors 

 Provisions to accept new FPS flame scanners 

 Three Type K permanent thermocouples to monitor coal nozzle and 

burner outer sleeve temperature with common junction box shop 

mounted on burner coverplate 

 Ceramic throat tile assemblies to reduce existing furnace waterwall 

openings 

 Field insulated burner coverplate 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-4 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

 Burner support rails and attachment hardware 

1 Lot – Burner line resistor sleeve engineering analysis to identify number and 

sizing of resistor sleeves. Each required resistor sleeve includes flanges, 

nuts, bolts, washers and gaskets. Pricing supplied in Section 4 will be per 

resister sleeve – the exact quantity (up to 36) will be determined during the 

contract phase. 

Qty 12 – Dual Zone OFA Ports 

 Each OFA port to include: 

 Barrel assembly with pitot tube relative air flow measuring device 

 Externally adjustable outer air zone spin vanes 

 Manually adjustable biasing damper for adjustment of the air flow split 

between the inner and outer zones 

 Total air flow control damper with Beck linear drive 

 Field insulated cover plate 

 Slip seal ring for attachment and seal to the furnace wall 

 Two, Type K permanent thermocouples to monitor core air sleeve and 

port outer sleeve temperature with common shop mounted 

thermocouple junction box 

 Four - Mass Air flow measurement equipment for each OFA windbox 

feeder duct. Pitot grid type device to be supplied with integral 

temperature measurement for direct output of mass air flow. 

 Dual Zone NOx Port support rails and attachment hardware 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-5 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Qty 2 – New OFA windbox extension, one on the front furnace wall and one on the 

rear furnace wall, supplied to house the new OFA Ports and convey 

secondary air to the new OFA port inlets. Each extension will be constructed 

with an internal support steel structure with casing and stiffeners and 

designed for current NFPA internal pressure requirements and be compatible 

with new boiler pressure increase requirements. 

Item 3: Fossil Power Systems Oil Igniters 

 (same scope applies to both Item 1 and Item 2) 

Qty 42 – FPS 4.5” Oil Igniters will be supplied for ignition of the main fuel. 

Each igniter includes: 

 SunSpot ignitor flame detector electronic module (mounted in valve rack 

cabinet) 

 SunSpot flame rod complete with high temperature extension and metal 

braided flex conduit assembly 

 Plasma Arc Ignition (PAI) system, with the burner-front Power Pack in a 

NEMA 4 enclosure. 

 Low voltage spark plug assembly complete with high temperature 

extension and metal braided flex conduit assembly. 

 1⁄4” X 48” stainless steel oil hose with quick coupler. 

 3⁄8” X 48” stainless steel air hose with quick coupler. 

 Combustion/cooling air connection with gate valve for adjusting air flow. 

Each ignitor requires 140 SCFM of combustion air at 2-4” above furnace 

pressure. 

Item 4: OFA Insert Panels 

 

 Qty 12 - New bent tube waterwall openings - 1 for each OFA port

 CFD modeling of the OFA system 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-6 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Option A: B&W FocalPointTM Optimization System 

The proposed system will include B&W’s FocalPointTM advanced 

optimization software, an O2/CO emissions grid for the convection pass 

of the boiler, and automation of the core air zone of the OFA ports. The 

FocalPointTM system will be configured with proven optimization 

strategies designed specifically for improved CO and NOx control using 

B&W’s dual-zone OFA ports. 

Option B: Fossil Power Systems Main Flame Scanner System

B&W understands that Flint Creek 1 has a relatively new Forney flame 

scanning system and AEP is happy with its performance. B&W wishes 

to note that a new flame scanning system is not inherently required with 

the new burners. AEP may consider the FPS scanner system as 

optional scope and not absolutely necessary if the existing system is will 

be retained. 

It should be recognized that reuse of the existing scanners may or may 

not require some modification to that system. Costs for modification of 

the Forney equipment for reuse with the new burners has not been 

included herein but B&W would expect such costs to be minimal if any. 

FPS main flame scanning system to included: 

Qty 42 – FPS rigid fiber-optic, dual-color (VIS/IR) flame scanners for 

monitoring main coal flames. The flame scanners shall be 

tuned for black furnace protection and individual burner 

discrimination. 

Qty 42 – FPS fiber optic scanner guide pipes and associated mounting 

hardware with cooling air connection. Guide tube is equipped 

with an attached plug / air flow restrictor for installation in the 

guide tube when the viewing head is removed. 

Qty 21 – Two-channel burner front junction boxes complete with 23 ft 

prefabricated cables (2 each) for connecting to two scanner 

heads. 

Qty 1 – Skid mounted duplex blower assembly. Blower is sized to 

supply combustion air for 42, FPS 4.5” oil ignitors and cooling 

air for 42, FPS Fiber Optic Flame Scanners 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-7 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Option C: Fossil Power Systems Duplex Blower Skid and Air Piping 

B&W understands that Flint Creek 1 has igniter combustion and scanner 

cooling air blower systems which are relatively new and it is likely these 

blower and their associated air piping systems can be reused. 

However, if it is found that the air requirement of the new igniters cannot 

be met by the existing blower and/or a new scanner system is elected 

which requires more air than the existing system can supply, B&W offers 

to furnish a new FPS duplex blower skid and associated piping to supply 

the required combustion and cooling air. 

Skid mounted duplex blower assembly is sized to supply 125% 

combustion/cooling air for (42) FPS 4.5” oil ignitors (42) main flame 

scanners. The duplex blower skid and piping will include: 

Qty 2 – Blowers with direct drive, premium efficiency motors (Motors 

sized to handle unrestricted flow) 

Qty 2 – Check valve and butterfly isolation valve on each blower outlet 

Qty 1 – Common discharge pipe with pipe stub outlet and rubber 

sleeve with clamps 

Qty 2 – Inlet filter-silencers 

Qty 2 – Inlet pressure switches 

Qty 2 – SPDT pressure switches to monitor discharge pressure, wired 

into starter circuits to allow automatic switchover on loss of 

discharge pressure 

Qty 2 – Air connections to pressure switches factory installed 

Qty 2 – Circuit breaker type full voltage combination starter 

assemblies in NEMA 4X enclosures, each with switches and 

indicators to allow local control and monitoring of blower 

operation. Starters are factory mounted on blower skid and 

wired such that loss of discharge pressure will automatically 

cause the standby blower to start 

1 Lot – Pre-wired connections between motors, starters and pressure 

switches 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-8 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Qty 1 – Common Pipe Discharge (plain pipe end) 

1 Lot – Air piping and supports from the blower skid to the burner 

fronts. 

General Services Scope of Supply Included Unless Noted Otherwise 

 Field Service Engineering support totaling up to 50 man-days over the scheduled 

installation outage including pre-outage activity. B&W Field Service Engineer(s) 

will assist AEP SWEPCO with on-site training, commissioning and start-up of the 

new burner system and associated equipment furnished by B&W. 

 Burner system operator training per the conformed specifications 

 Tuning and Guarantee performance testing services including temporary 

emissions monitoring equipment, gas sampling test probes, and required test 

personnel. Performance testing will include a combustion system design engineer 

for complete unit tuning. The provided test sampling is intended for use during the 

optimization and tuning period. Due to the erosive flue gas environment, these 

probes would need to be removed from the duct and re-inserted on an as-needed 

basis and are not permanent instrumentation. 

 Brickwork Refractory Insulation & Lagging (BRIL) design 

 Operating and Maintenance Manuals 

 Delivery F.O.B. Flint Creek Power Station 

 System Requirements Specification, I/O Listing, Functional Logic Diagrams, 

Process & Instrumentation Diagrams for supplied equipment 

 Site visits to ensure fit up and confirm the design with regard to interferences 

 Project Management 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-9 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

Items Not Included 

The following list is provided as a convenience to illustrate the items and services 

NOT included in the proposed scope of supply. Items listed below may be required 

for proper unit operation but are outside the scope of this proposal. There is no 

implication that items not listed will be furnished by B&W. 

 Coal line resistor sleeves, although the engineering analysis to determine the 

necessary quantity is. Per unit resistor sleeve pricing is provided in Section 4 of 

this proposal 

 Burner related refractory, refractory re-work or refractory clean up 

 Demolition or installation services 

 Insulation and lagging materials or installation 

 Permits, licenses, and other Governmental Agency permission required to 

construct and operate the proposed equipment 

 Design, supply, and installation of existing control system I/O hardware additions 

(if required) for the proposed burner equipment 

 Finish painting of B&W-furnished burner equipment. If applicable, the equipment 

would be provided with a shop-applied primer coat. Vendor-supplied equipment 

would be furnished with the vendor's standard finish 

 Federal, State or Local sales and use taxes 

 Bid bond, performance bonds, or security deposit 

 Electrical and Controls-related items as follows: 

o Site Specific Configuration drawings 

o Control system hardware and/or software (including programming) 

except as noted in the scope of supply items listed above 

o Confirmation or modification of existing logic 

o Power supplies 

o Wiring design, supply, or installation between Contractor’s 

equipment and the DCS or power supplies 

 Ignitor oil main headers, regulating stations, pumps, or anything upstream of the 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 3 Page 3-10 

Scope of Supply 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

inlet flanges at the FPS oil control valve racks on each burner elevation 

 Hydrostatic testing 

 Boiler circulation analysis 

 Drawings in native file formats (i.e., .dwg). 

 Commissioning Spares or replacement parts 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 4 Page 4-1 

Not Used 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

4. NOT USED 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 6 Page 6-1 

Expected Emissions Performance 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

5. SCHEDULE 

This budgetary schedule is based upon availability of Babcock & Wilcox Power 

Generation Group, Inc. resources at the time of this Budgetary Proposal. These 

resources are subject to conditions of prior sale which may affect the final contract 

schedule. Upon notification of award, this preliminary information will be reviewed 

with AEP SWEPCO and a contract schedule would be issued. 

 

Milestone Weeks 

Receipt of Acceptable Purchase Order 0 

Engineering Release of Purchased Material Orders 8 

CFD Modeling to Determine Size and Position of OFA Ports 10 

Rev-0 General Arrangement Drawings Submitted 20 

Start Pressure Part Fabrication 22 

Start Burner Fabrication 26 

Delivery to Site – Pressure Parts 34 

Midpoint of Burner Fabrication 36 

Delivery to Site – Burner Components 46 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 6 Page 6-1 

Expected Emissions Performance 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

6. Expected Emissions Performance 

When the steam generating unit is retrofitted with new combustion equipment as 

described in this proposal, the Contractor expects the following unit performance. 

The ranges of expected emissions performance below may be subject to some 

variation depending on the final, mutually agreed design/guarantee basis operating 

conditions. Further, if the conditions during performance testing differ from the 

design/guarantee basis, then the as measured performance will be corrected to the 

design/guarantee basis conditions in accordance with the ASME Power Test Code 

(PTC). 

The precise NOx emission rate the unit ultimately runs at will depend on burning a 

PRB coal with certain constituent limits. The ranges below attempt to capture the 

range of performance applying B&W’s known database of PRB coal. 

Expected Emissions 

A. Nitrogen Oxide (NOx) Emissions (“Full Load” Condition) 

The average NOx emission rate over a single 4 hour test period, expressed as NO2, 

leaving the economizer is expected to be with the following ranges: 

Table 6.1: Expected NOx

Equipment Condition NOx ( lb/ 106 Btu/hr) 

AireJet Burners 

(Item 1) 

42 or 35 Burners in Service 

@ MCR Load 0.145 – 0.20 

DRB-4Z Burners 

(Item 2) 

42 or 35 Burners in Service 

@ MCR Load 0.165 – 0.218 

The NOx ranges in Table 6.1 account for the number of burners in service at MCR 

and also for the variation in fuel characteristics that B&W has recorded as being 

associated with PRB coals of the type expected to be used at this facility. 

The precise NOx and CO emission rates as measured at the time of the performance 

test will be a result of the combustion equipment type and design selected and will 

also be a result of the specific operating conditions and fuel characteristics associated 

with this facility as described in section 6.C and 6.D below. 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 6 Page 6-2 

Expected Emissions Performance 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

B. Carbon Monoxide (CO) Emissions (“Full Load” Condition) 

The average CO concentration in the flue gas leaving the economizer and 

corresponding with the NOx emissions values presented in table 6.1 will not exceed 

200 ppm by dry volume, corrected to 3% O2.

C. Fuel Impacts 

Certainly, coal quality impacts NOx emissions and changes from one analysis to the 

next can produce slightly different expectations for such emissions. 

As part of the emissions performance evaluation above, B&W considered the 

approximately 50, “as-received” PRB coal analyses in our database. When NOx 

emissions are considered across the range of those PRB coals, B&W predicts that 

NOx emissions may fluctuate about 0.03 lbs/106

 Btu/hr across the range and this 

variation has been included in table 6.1 above. Fuel analysis fluctuation is one 

reason why sometimes day-to-day NOx performance of a boiler varies from the 

original guarantee values. 

Indirectly, coal quality may affect unit operation which impacts NOx performance. 

One example of this would fuel that is more prone to slagging or fuel that is wet. In 

such instances, plant operations may require that excess air be raised to minimize 

slagging but increasing excess air almost always means an increase in NOx 

emissions. 

D. Operational Impacts 

B&W typically expects degradation in NOx emissions performance of about 10% 

given any one pulverizer group out of service except if that group is associated with a 

top burner row. For a top row pulverizer group out of service, NOx emissions would 

be expected to be no worse than with all burners in service. This variation has also 

been included in the range of performance listed in table 6.1. 

Although it is not possible to quantify their precise effects, other operational 

parameters which may impact NOx and CO performance include excess air to 

combustion equipment, secondary air temperature, pulverizer exit temperature, line to 

line coal balance, and windbox static pressure. 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 6 Page 6-3 

Expected Emissions Performance 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

E. Operational History 

Other recent radiant boiler (RB) units with AireJet burners installed and without SCR’s 

so EPA emissions data would be available to demonstrate day-in-day-out emission 

levels are: 

 Nebraska Public Power – Gerald Gentleman Unit 2 (2012) 

 Basin Electric – Laramie River Unit 1 (2012) 

 PacifiCorp – Wyodak (2011) 

 City of Sikeston (2013) 

Other recent radiant boiler (RB) units with DRB-4Z burners with OFA installed and 

without SCR’s so EPA emissions data would be available to demonstrate day-in-dayout emission levels are: 

 Portland General Electric – Boardman (2011) 

 AEP SWEPCO – Welsh Units 2 & 3 (2005, 2001) 

 Public Service of New Mexico – San Juan Unit 3 & 4 (2008) 

 
Low NOx Combustion System Proposal No. P006876-R4 

AEP SWEPCO June 20, 2013 

Flint Creek Unit 1 

Section 6 Page 6-4 

Expected Emissions Performance 

Copyright  2013 Babcock & Wilcox Power Generation Group Inc. 

All rights reserved. 

To provide additional detail on one of the units above, the below chart shows the 

performance over the load range for Gerald Gentleman Unit 2. This unit was retrofit 

with AireJet burners in 2012 and continues to operate within its guaranteed 

emissions. 

The plotted trend of load versus emissions is typical of the AireJet burner with higher 

NOx rates occurring at due to higher levels of excess air being applied.