Introduction

This course, which is of three (or four) days duration is aimed at engineers and management personnel of process plants, cogeneration plants, power plants, refineries and steam plants who are involved with boiler or heat recovery equipment performance aspects and engineering/ operation of waste heat boilers and HRSGs. It highlights process heat transfer aspects, boiler design features, recent trends in boiler design, what to look for in a good design or identify a poor design, evaluation of operating parameters and regimes and critical issues such as: boiler/HRSG efficiency evaluation, steam purity, heat flux and circulation, effect of fuels on boiler performance, deviations from design operating point, economizer steaming, evaluating field data for possible process problems, identification of problems in superheaters, evaporators or economizers, air heaters , operating cost minimization through proper evaluation of offers before specifying the boilers and pollution control issues. Typical field problems or issues from process viewpoint such as fouling, corrosion, efficiency improvement and modifying existing equipment for better performance will also be discussed. The discussions are more process and thermal design oriented and not on mundane operating issues such as flash steam recovery or excess air adjustments for energy improvement. The author feels that lot of plants buy steam generation equipment without understanding the process aspects and then spend lot of money and time later fixing the equipment to meet specified plant performance needs.

Basically it is a course dealing with thermal and process issues which can help plant/design and operating engineers to understand or improve their equipment performance. It is more of an education in thermal process behind these boilers/heat transfer equipment, which will give an all-round understanding of various design and operating issues. For example, I may not be able to discuss in detail what chemicals to use for water treatment as it is more of a chemist's business but I can relate the problems of poor boiler or feed water chemistry on boiler fouling, tube failures and steam purity, carry over, superheater failures, steam temperature variations etc. Similarly if the waste heat boiler is operating at off-design conditions, is it meeting the original design expectations or performing poorly? If a tube failure has occurred, is it due to fouling on tube or steam side? What happens if the gas flow or gas inlet temperature to the HRSG changes? Often operating engineers have no way of evaluating these issues and depend solely on the boiler supplier, who may or may not be able to offer timely help. This course will emphasis such aspects and offer simple tools for understanding and evaluating boiler/HRSG performance or problem areas.

The contents are given below. It is planned as a three day course with discussions on:

design and off-design performance of boilers/HRSGs, field problems and solutions, demonstration of software for boiler performance understanding/calculations and HRSG simulation which helps understand performance of HRSGs without even knowing its mechanical design features. Using simulation concepts, one plan new HRSG projects or optimize the HRSG configuration before even purchasing the HRSG.The course material will be in the form of power point presentations as shown below. Also several articles published by me are available from my web site, which can be downloaded

free of cost and can form additional course material. You may also purchase copies of my

latest book, "Industrial Boilers and HRSGs" if interested, which has over 230 fully worked out examples on boiler design and performance aspects and steam plant calculations.

Oil/gas fired steam generators

Boiler basics-boiler classification-package boilers-A,D,O types-custom designing-recent trends.

advantages of completely water cooled furnaces-membrane wall vs tangent tube designs.

why economizer is preferred to an air heater for heat recovery-boiler performance aspects-oil vs gas firing-variation of steam temperature, efficiency etc with boiler load-minimizing operating costs-furnace design-performance-

effect of fuels on furnace duty-heat flux-boiling process-understanding heat flux-heat release rates-boiler circulation-superheaters-radiant vs convective designs and problems-Materials for boilers-steam temperature control methods. Why refractory is avoided in recent designs- boiler surface area comparison or significance of surface areas-effect of steam pressure on operation-heat losses in a boiler and efficiency calculations-short method-field data analysis-efficiency on HHV ,LHV basis-relating excess air with oxygen in flue gases-Simplified combustion calculations-multiple fuel firing-fan selection issues-blow down and steam purity issues-specifying steam generators- effect of emission regulations on design and performance-what to look for while buying/selecting future boilers- drum level fluctuations with load-effect of fuel on boiler performance-low and high temperature corrosion problems-requirements for quick startup-effect of gas pressure drop on boiler design and size-how to evaluate boilers before buying them. Effect of emission regulations on boiler design or operation.

Waste heat boilers & HRSGs

Classification-fire tube and water tube boilers-boilers in hydrogen plants(reformed gas boiler, flue gas boiler) sulfur plants(claus plants,sulfuric acid plants)-solid, gaseous, liquid waste incineration heat recovery systems and gas turbine or diesel engine exhaust HRSGs-design features of different applications-performance-importance of flue gas analysis-low and high temperature fouling and corrosion issues and minimizing the problems-Insulation selection-hot and cold casing designs-acid dew point calculations-unfired, supplementary fired and furnace fired HRSGs-burner calculations- why fired HRSGs are more efficient than unfired units-Savings in fuel consumption-fresh air firing -HRSG efficiency calculations-economizer steaming-what is it, why it occurs and how to avoid it-performance variation with load-Effect of ambient temperature on HRSG performance-how to combine operation of steam generators and HRSGs to minimize overall fuel consumption-natural vs forced circulation HRSG designs-fouling inside and outside tubes and how to minimize the concerns-effect of emission regulations on boiler design and performance-relating field data with design and evaluation of potential problems-drum sizing, drum internals, steam purity concerns-comparison between fire tube and water tube boilers-Use of fins or bare tubes-noise and vibration analysis-material selection. Importance of gas pressure drop-drum internals, water chemistry issues-how to develop waste heat boiler specifications from process view point.

Applied heat transfer

Heat transfer basics-heat transfer inside and outside bare and finned tubes-advantages of finned tubes. comparison with bare tube boilers-effect of tube size on heat transfer and tube wall temperature-importance of fin configuration on heat transfer and surface areas-optimization through proper fin geometry-how surface areas can be misleading especially with finned tubes.

Solid and serrated fins-inline vs staggered arrangement of tubes-effect of fin configuration on tube and fin tip temperatures-scale formation and impact on tube wall temperatures-tube bundle vibration-predicting performance of furnaces, evaporators, superheaters, air heaters and economizers, off design calculations. Evaluating field data. Use of NTU method to predict boiler performance-effect of steam demand on steam pressure, drum level. Calculation of convective, non-luminous radiation coefficients. Simplified performance predicting methods for boiler components.Tube wall temperature, tube life estimation.

HRSG simulation

What is simulation-understanding pinch and approach points-how to predict temperature profiles and performance of a given HRSG and check if it is operating-well-how to predict performance of HRSGs under different gas inlet temperatures-steam pressures, feed water temperatures, load conditions, unfired or fired conditions using the simulation program-planning future HRSG projects using simulation-how to optimize heat recovery-single or multiple pressure units, fresh air firing and fuel consumption-oxygen depletion and exhaust gas firing. Illustration with practical examples-optimizing HRSG configuration or maximizing energy recovery using simulation.

Cogeneration

Optimizing steam generation using HRSGs and steam generators. Understanding efficiency characteristics of each type of boiler vs load.

Pollution Control

Emissions in boilers and HRSGs. Methods of control of CO and NOx. Use of SCRs and Flue gas recirculation in boilers. Impact on boiler performance. Cost of pressure drop. Calculations for conversion of pollutants from mass to volume units.

POWER POINT PRESENTATION

The course will be conducted through power point discussions and exchange of thoughts, experiences between the course director and participants. Boiler problems relating performance issues can also be discussed. The following slide shows will be presented as part of the course. The emphasis is on process and applied heat transfer aspects.

· Introduction

· Steam generators

· Waste Heat Boilers

· HRSGs for gas turbines, diesel engine exhaust

· HRSG simulation

· Emission control

· Applied Heat Transfer

· Power systems

· Cogeneration

· Water chemistry issues·

· Quiz

Demonstration of HRSGS simulation program and general boiler programs will be included in the course. They are also available for purchase. It is also possible to model your HRSG so that future performance evaluation can be easily done.

USEFUL ARTICLES( may be downloaded from my web site.

https://vganapathy.tripod.com/boilers.html)

COURSE DURATION: 3 or 4 days of about 7 hour duration suggested with probably half a day for plant problems, discussions on boiler design or performance aspects, improvement of equipment performance. These may be referred by the participants. If advance information is given, these can be discussed if it is in the larger interests of the audience. This is an intensive course and participants are expected to have some background in boiler or heat recovery equipment design/operation/performance aspects and some process, heat transfer knowledge.

Background of V.Ganapathy

Education: B.Tech from IIT, Madras 1969 in Mech engg and Msc(engg) in Boiler Technology in 1972 from Madras University.

Professional Experience:

BHEL, Trichy:, boiler plant 1972-1982: Served in various positions in Research and Engineering, Boiler design and proposals and responsible for basic engineering of a coal based combined cycle research plant. Utility and industrial boiler performance and design.

1982-1984:Engineer at Struthers ThermoFlood in Winfield, Kansas, USA, involved in engineering of once through steam flood boilers for oil field applications.

1984-2003:Boiler Specialist at ABCO Boilers in Abilene,Texas, involved in design of steam generators and waste heat boilers for a variety of applications in process and power plants. Designed over 100 customized packaged boilers, over 350 water tube and fire tube waste heat boilers and HRSGs, which are in operation today, for FCC units, incineration (solid, liquid and fume ) systems, hydrogen and sulfur plants, gas turbine plants and custom designed systems for various process applications. Developed software for design of steam generators and waste heat boilers and programs for steam plant engineers including HRSG simulation, a program that predicts design as well as off-design performance of complex, multiple pressure, unfired and fired HRSGs.

2003-present: Boiler Consultant at Chennai, India. Consultant for a USA boiler company; developing programs for boiler/heat recovery applications.

Other: Authored over 250 articles on boiler design, heat recovery, boiler heat transfer and calculations, which have been published in numerous professional journals such as Chemical Engineering, Hydrocarbon processing, Power, Power Engineering, Plant Engineering, Chemical Engineering Progress and in UK and India. Authored 5 text books, the latest being, ”Industrial Boilers and HRSGs”, published by Marcel Dekker, New York. .Contributed several chapters to Handbook of Mechanical Engineering Calculations and Encyclopedia of Chemical process and Design, published by Marcel Dekker.

Conducted courses on boilers and heat recovery in India and in Venezuela for PDVSA refineries, RIPI in Tehran, Iran, Reliance, Saudi Aramco in Bahrain, Thermax, IPCL, NTPC, L&T in Baroda to mention a few.

Introduction

Contents

HRSG simulation