TECHNICAL TRAINING For Coal Boilers

1. TECHNICALTRAININGForCoal Boilers Matt Zedler Product Development January 22 Rev0

2. A power plant is a factory that is used to manufacture electric power. Power is energy that is used to produce work. Electric power is sent through wires where it can be used to spin motors, light lights, or for many other uses! Power plants can convert chemical energy in fuel (coal, gas, oil, nuclear) to electric power, or they can capture energy present in other forms (wind, water, solar) Background & History What is a POWER PLANT?

3. Coal Boiler Basic Training Background & History Boiler Components Boiler Types Further Learning

4. Background & History What is a BOILER? 锅 (guo1) means “pot” • “Boiler” = steam generator; uses heat to change water to steam • Heat can come from a variety of sources (coal, oil, gas, biomass, uranium, solar energy) • Typically divide the fossil-fueled boiler into two main systems: • 炉 -Fuel & fire side (fuel & air handling, combustion, radiation and convection heat transfer, exhaust) • 锅 – Water & steam side (feedwater pumps, tubes & downcomers, drum) • Used for power generation, municipal heating, industrial applications, etc. • Can be stationary or mobile (package boiler, boilers on ships) 炉 (lu2) means “furnace” Even the energy of the sun can be used to make steam in a boiler! The hot exhaust from combustion can be used to generate steam in a “heat recovery steam generator” (HRSG) Fossil fuels are burned in boilers

5. Background & History Boiler History 锅 (guo1) means “pot” • Greeks first used steam to drive a simple toy in 200 BC • Serious development began in 1600s AD • England led the world in steam power development during the industrial revolution • Limited by materials – as steel became available, boilers could go to higher temperatures and pressures 炉 (lu2) means “furnace” 1800s Babcock & Wilcox boiler Early 1700s kettle-type boiler Modern subcritical boiler

6. Boiler Components Fire-Side (炉) Looking down in furnace of corner-fired unit • Any fossil fuel requires oxygen to combust • Simply put, the furnace is simply a container for air and fuel to mix, combust, and release heat • Pulverized fuel and air are pushed into the bottom of the furnace by fans (forced draft), and hot exhaust is pulled out of the back of the furnace by different fans (induced draft) • Heat is released in the “front pass” primarily through radiation (tubes “see” the fire) • In the “back pass,” heat is released through convection (tubes “feel” the heat as hot gas passes over them) • Burning fuel releases tremendous heat (2000°C temperatures), melting any solids in the fuel • Combustion also releases pollutants: • Nitrogen oxides (NO, NO2 = NOx) – causes smog • Sulfur oxides (SO3 = SOx) – causes acid rain • Particulate matter – small amounts of solids • Mercury (Hg) – poisons water supplies • Carbon dioxide (CO2) – greenhouse gas 炉 (lu2) means “furnace” FRONT BACK Fuel (chemical) energy is changed to heat in the FURNACE Heat is released in FRONT and BACK passes of the boiler

7. Boiler Components Fire-Side (炉): Air A 60 megawatt (MW)* power plant requires 220 metric tons per hour of steam. To produce the steam, 37 metric tons per hour (37,000 kg/hr) of coal are required. Therefore, roughly 260,000 kg/hr of air are required (7 x 37,000 kg/hr). That’s roughly 56 m3 of ambient air every second!! *One megawatt is 1,000,000 watts. Therefore, a 60 MW plant makes enough power to light 600,000 100 W light bulbs! • Large fans are needed to move the amount of air required for burning coal – each kilogram of coal typically requires 6 to 8 kilograms of air • Forced draft fans (FDFs) pull in ambient air. Ducts are used to move the air to the boiler. The windbox is the final section of ductwork that connects to the burners. An air preheater (APH) can be used to take waste heat from the exhaust and heat incoming air. • Air is also used to move pulverized coal. Air with coal is called primary or tertiary air while air with no coal is called secondary air. Ductwork is LARGE – lots of air! AIR OUT AIR OUT APH (Single pass) Hot gas gives heat to cooler air AIR IN FDF Side View FDF, Showing Motor

8. Boiler Components Fire-Side (炉): Fuel Crushed coal going into a storage bin • Solid fuel burns best when crushed to a very fine powder (pulverized – 60% to 70% of coal entering a boiler is less than 75 microns in diameter! • Fuel is moved by conveyors, crushed, and then pulverized in several mills. • Mills use steel balls, rollers, or some sort of grinding element to pulverize the coal. • Air can then be used to convey pulverized coal to the burners. Coal passing through a vertical pulverizer is crushed by rollers Pulverized coal is like a fine dust – make sure not to breath too much in! FDF Side View

9. Boiler Components Fire-Side (炉): Fuel (Direct vs Indirect) • There are two main milling system configurations in use: • DIRECT – Primary air that enters the mill is used to then carry the coal to the burner (no tertiary air) • INDIRECT – After the coarse classifier, coal is separated from the air after and stored in a bin. Primary air is used to convey coal from the bin to the burner. The tertiary or milling air may either be used in the boiler or recirculated to the mill. A classifier is a piece of equipment that ensures particles that are too large (typically over 300 microns) are not sent to the boiler. The classifier can be internal to the mill (direct system) or external to the mill (indirect system’s coarse classifier) LP Amina has a patented classifier technology. FDF Side View Indirect System Direct System

10. Boiler Components Fire-Side (炉): Burners (Air + Fuel) • Coal and air are mixed and ignited in the burner zone. • Burners come in many different sizes and shapes, but the primary goal is ensure proper mixing. Poor mixing leads to incomplete combustion (typically represented by a large point of unburnt carbon or UBC). • Burners must be able to withstand very high temperatures, typically for several years of operation. • The tip of the burner is called the nozzle. Nozzles can sometimes tilt to raise or lower the location of the main combustion zone. Tangent-fired burner column (nozzles visible) Nozzles are typically labeled using letters, starting at the bottom of the burner column and moving up. Nozzles that have fuel are given a single letter (A, B, C…). Nozzles that are only air are labeled by the coal nozzles they are between (AB would be the air nozzle between coal nozzles A & B). Burnt-up coal nozzle Burner pipe spares FDF Side View Drawing of a wall-fired burner

11. Boiler Components Water-Side (锅) Nozzle opening in tube (membrane) wall • Complex system of tubes and pipes that gather heat from the furnace to change water to steam • Water (feedwater) is pumped to the steam drum at the top of the boiler, passing through the economizer on the way • Downcomers and headers carry water to the bottom of the boiler. • Water flows upwards to the steam drum through the membrane wall, absorbing heat and changing to steam. • Steam exits the steam drum at desired temperature and pressure • Steam drum separates steam and water in a subcritical boiler. There is no steam drum in a supercritical boiler (water is so hot and at such a high pressure it simply turns into steam without boiling) • Steam is typically at 13 – 17 MPa and 540°Cin subcritical boilers 锅 (guo1) means “pot” (pot is made of many tubes) Heat is collected and transferred to the end use in the water-steam system. Heat is released in FRONT and BACK passes of the boiler

12. Boiler Components Water-Steam System(锅:水气系统) The “pot” is very complex – boiler manufacturers want as much heat transfer as possible in a small area to save costs

13. Boiler Components Water-Steam System(锅:水气系统) Steam turbine converts heat to mechanical energy LOOP 1 MAKE STEAM Natural convection cooling LOOP 2 COOL STEAM Boiler uses fuel to change chemical energy into heat energy Steam turbine is fan spinning at 3,000 – 3,600 RPM Air cooled condenser Steam condenses back to water in the condenser Some hot water may go for district heating Once-through river / lake cooling Two separate water loops at all thermal power plants – Loop 1 water quality very important

14. Boiler Types Coal Boiler Types • Boiler design is determined primarily by the following: • Desired output steam conditions (pressure, temperature, flow rate) • Fuel type • Biggest differences are typically in boiler size and burner arrangement

15. Boiler Types Coal Boiler Types Wall-Fired Unit Corner / Tangent-Fired Unit

16. Further Learning References • Material for this training was primarily taken from the following sources, as well as the Internet and personal photo archives: • Kitto, J.B. & Stultz, S.C. Steam: Its Generation and Use (Ed.41). Babcock & Wilcox Company. USA : OH, Barberton (2005). • Drbal, L.F. Power Plant Engineering. Black & Veatch. USA : NY, New York (1996). • LP Amina is working on putting together more detailed technical references and trainings and would welcome any comments or feedback. Please direct any suggestions to M. Zedler in Product Development.

17. 燃煤锅炉技术培训 产品研发部 马修文 现场服务部 陈福兵 2013年01月26号 0修改

18. 电厂是用来发电的工厂。 电力是生产工作的能量来源。电能通过电线传输，具有提供动机所需动力、提供照明等诸多用途. 电厂可以将储藏在燃料（煤、天然气、石油、原子核）里的化学能量转化成电能，或利用其他形式（风、水、太阳）的能量。 背景与历史 什么是电厂

19. 燃煤锅炉 - 技术培训 背景与历史 锅炉部件 锅炉型 进一步学习

20. 背景与历史 什么是锅炉？ 锅 (guo1) means “pot” • 锅炉 = 蒸汽发生器，通过热能将水转化为蒸汽 • 热能来源广泛（煤、石油、天然气、生物、铀、太阳能等） • 一般将化石燃料锅炉分为两大系统： • 炉 – 燃料和火焰（烟风） （燃料与空气处理、燃烧、热辐射与对流传热、废物） • 锅 – 水和蒸汽 （给水泵、管道和下降管、集箱） • 用于发电，城市供暖、工业应用等 • 分为静态和动态（整装锅炉、作为轮船动力的锅炉） 炉 (lu2) means “furnace” Even the energy of the sun can be used to make steam in a boiler! The hot exhaust from combustion can be used to generate steam in a “heat recovery steam generator” (HRSG) Fossil fuels are burned in boilers

21. 背景与历史 锅炉简史 锅 (guo1) means “pot” • 公元前200年，希腊人首先利用蒸汽推动一个简单的玩具 • 公元1600年后，对蒸汽用途的严肃研究拉开了帷幕 • 工业革命时期，英国引领世界进行蒸汽发电研发 • 起初受限于材料，后来随着钢材的出现，锅炉可以达到更高的温度和压力。 炉 (lu2) means “furnace” 1800s Babcock & Wilcox boiler Early 1700s kettle-type boiler Modern subcritical boiler

22. 锅炉部件 Fire-Side (炉) Looking down in furnace of corner-fired unit • 任何化学燃料都需要氧气进行燃烧 • 简言之，炉就是空气与燃料混合、燃烧并释放热能的容器。 • 通过送风机（强制通风）将煤粉和空气送入炉底部，热废气通过引风机（诱导通风）从炉后排出。 • 在前炉膛（水冷壁）主要以辐射换热为主（即：火焰和高温烟气没有与管道接触） • 在后炉膛主要以对流换热为主（在高温烟气通过时，直接冲刷管道） • 燃烧燃料产生很高温度（2000摄氏度），将燃料中的所有固体都熔化（如果煤颗粒在 熔化前，没有被燃烧掉，就会结渣。） • 燃烧会产生的污染物： • 氮氧化物(NO, NO2 = NOx) – 产生烟雾 • 硫化物(SO3 = SOx)- 产生酸雨 • 悬浮颗粒物 – 少量的固体颗粒 • 汞(Hg)– 污染水源 • 二氧化碳(CO2)– 温室气体 炉 (lu2) means “furnace” 前 通过 后 通过 Heat is released in FRONT and BACK passes of the boiler Fuel (chemical) energy is changed to heat in the FURNACE

23. 锅炉部件 Fire-Side (炉): 空气 A 60 megawatt (MW)* power plant requires 220 metric tons per hour of steam. To produce the steam, 37 metric tons per hour (37,000 kg/hr) of coal are required. Therefore, roughly 260,000 kg/hr of air are required (7 x 37,000 kg/hr). That’s roughly 56 m3 of ambient air every second!! *One megawatt is 1,000,000 watts. Therefore, a 60 MW plant makes enough power to light 600,000 100 W light bulbs! • 风机提供燃烧所需的空气 —— 每千克煤通常需要6至8千克空气 • 送风机(FDF) 将周边空气引入。风道将空气导入锅炉。风箱是风道系统的最后一个部分，连接燃烧器。预热器(APH) 可以将废气中的热能传导至进入系统的空气，从而加热空气,在空气被燃烧之前，对其进行预热（所以叫预热器）。 • 空气还用于运送煤粉。夹带煤粉的空气称为一次风或三次风，没有夹带煤粉的空气称为二次风。 Ductwork is LARGE – lots of air! AIR OUT AIR OUT APH (Single pass) Hot gas gives heat to cooler air AIR IN FDF Side View FDF, Showing Motor

24. 锅炉部件 Fire-Side (炉): 燃料/煤 Crushed coal going into a storage bin • 当被研磨成非常细小的粉末时，固体燃料的燃烧效果最好。（这些送入锅炉的细小粉末有60% 至 70%的煤粉颗粒直径小于75微米）！ • 传送器运送煤粉，煤料被压碎，并在几个磨煤机里磨成细小颗粒 • 磨煤器使用钢球、辊子或者其他研磨部件研磨煤料 • 空气用于将煤粉运送至燃烧器 Coal passing through a vertical pulverizer is crushed by rollers Pulverized coal is like a fine dust – make sure not to breath too much in! FDF Side View

25. 锅炉部件 Fire-Side (炉):燃料/煤（直接与间接） • 现在常见的主要有两种研磨系统结构： • 直接： 一次风送入磨煤机，然后携带煤粉至燃烧器（没有三次风） • 间接：煤料在经过粗粉分离器后，与空气分离，并将其储藏在煤粉仓中。一次风用于将煤粉从煤粉仓输送至燃烧器。三次风或者研磨空气可以用于锅炉或者磨煤器再循环。 A classifier is a piece of equipment that ensures particles that are too large (typically over 300 microns) are not sent to the boiler. The classifier can be internal to the mill (direct system) or external to the mill (indirect system’s coarse classifier) LP Amina has a patented classifier technology. FDF Side View Indirect System Direct System

26. 锅炉部件 Fire-Side (炉):燃烧器（空气+燃料/煤粉） • 在燃烧器区域，煤粉与空气混合，并被点燃。 • 燃烧器的形状大小不尽相同，但总的原则是保证正确的煤与空气的混合。混合不充分会导致不完全燃烧（最典型的是体现在大块的未完全燃烧碳上，即：UBC） • 燃烧器应确保耐磨、耐磨损，一般为一个锅炉大修周期 • 燃烧器前端称为喷嘴。喷嘴可以上下摆动来抬高或降低主燃烧区域位置。 Tangent-fired burner column (nozzles visible) Nozzles are typically labeled using letters, starting at the bottom of the burner column and moving up. Nozzles that have fuel are given a single letter (A, B, C…). Nozzles that are only air are labeled by the coal nozzles they are between (AB would be the air nozzle between coal nozzles A & B). Burnt-up coal nozzle Burner pipe spares FDF Side View Drawing of a wall-fired burner

27. 锅炉部件 Water-Side (锅) Nozzle opening in tube (membrane) wall • 复杂的管道系统吸收燃烧炉的热量，并将水 • 转化为蒸汽 • 将水（锅炉给水）泵入位于锅炉顶端的上汽包，途经省煤器 • 下降管和联箱将水运送至锅炉底端（水冷器下集箱） • 水流经过水冷壁向上流至上汽包，吸收热量，并转化为蒸汽 • 蒸汽在上汽包内达到预定的温度和压强 • 上汽包将亚临界锅炉的水蒸气和水分开。 • 超临界锅炉没有汽包（水太热了， • 高压下直接转化成蒸汽，无需沸腾） • 亚临界锅炉里面的水蒸气压强为 • 13 – 17 MPa，温度为300 - 540°C。 锅 (guo1) means “pot” (pot is made of many tubes) Heat is collected and transferred to the end use in the water-steam system. Heat is released in FRONT and BACK passes of the boiler

28. 锅炉部件 Water-Steam System(锅:水气系统) The “pot” is very complex – boiler manufacturers want as much heat transfer as possible in a small area to save costs

29. 锅炉型 燃煤锅炉型号 • 锅炉设计首先有以下因素确定： • 预期输出蒸汽条件（压强、温度、流速） • 燃料类型 • 锅炉间差异的最主要因素是大小和燃烧器布置

30. 锅炉型 燃煤锅炉型号 Wall-Fired Unit Corner / Tangent-Fired Unit

31. 进一步学习 参考文献 • 以下为此培训材料的参考文献，包括一些专著、网上和个人图片库。 • Kitto, J.B. & Stultz, S.C. Steam: Its Generation and Use (Ed.41). Babcock & Wilcox Company. USA : OH, Barberton (2005). • Drbal, L.F. Power Plant Engineering. Black & Veatch. USA : NY, New York (1996). • 阿米那正在备至更加详尽的培训材料，并欢迎大家评论与反馈。请直接联系产品研发部马修文。