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专业英语 第六章 教案
单词和词组
Ab initio 从头开始 Abnormal 异常的 Admiion valve 进气阀 Auxiliary 辅助的 A myriad of 大量的 Ae 评估
Be vital of 为…不可缺的 Carryover 携带 Category 种类 Control panel 控制盘 Categorise vt.分类 Cold start 冷态启动 Controllability 控制性能 Commiioning 试运行 Conservative 保守的 Console 仪表板，控制台 Contamination 污物
Condensate storage tank 凝结水箱 Condensate hotwell 凝汽器热井 Debris 碎屑 Deposits 沉积物
De-aerator storage tank 除氧器水箱Drain pipe 排水管
di-sodium phosphate 磷酸二钠 Duplicated 重置的 Energize 通电，供电 Electrical distribution system
In sequence 顺序 Limestone 石灰
Localized corrosion 局部腐蚀 Log 运行日记
Lube oil system 润滑油系统 Monitor 监控 Mill scale 氧化皮 Mill 磨煤机 Moisture 水分 Mandatory 强制的 Megawatt 兆瓦 Overlaid 覆盖 Parameter 参数 Parallel in 并网 Paivation 钝化
Part and parcel of …的重要部分Personnel 人员
Pertinent 有关的，相关的 Procedure 规程 Preempt 先占，抢先 Portion 部分 Plug 堵塞
Pneumatic test 气密性试验 Pulverizer 磨煤机 Reveal 展现 Residue 残渣 Scrub 净化
33-1
配电系统 Erection 安装 Excitation 励磁 Feasibility 可行性 Flange 法兰
Finned surface 扩展受热面 Flush 冲洗
Forced draft fan 送风机 Harp 竖管排 Header 联箱 Hose 软管 Hot start 热态启动 Hydrostatic test 水压试验 Ignition 点火
Induced draft fan 引风机 Intermittent 间歇的 In the vicinity of 在附近 Inorganic 无机物的 Initial 初始的 In parallel 并行的 EPC 欧洲专利公约 EPO 欧洲专利局 FAQ 常见问题解答 HRSG 余热锅炉 MST 主蒸汽温度 MSP 主蒸汽压力
Seal 堵头 Silo 仓 Silica 二氧化硅 Standstill 停机 Solubility 可溶性 Sophisticated 完善的 Synchronize 同步
tri-sodium phosphate 磷酸三钠 Trip 事故停机，跳闸 Turning gear 盘车 Utilize 使用 Valve seal 阀门密封 Velocity 速度 Veel 容器，管道 Vendor 厂家 Vent 排气口 Void 空隙
Warm start 温态启动 Welding 焊接 简写
OEM 设备制造厂家 PCT 专利合作条约 RSP 再热蒸汽压力 RST 再热蒸汽温度 USC 超超临界 VWO 阀全开
Chapter 6 Unit System Operation
第六章 单元机组运行
6.1 Introduction 6.1 前言 6.1 Intrudction
33-2
For the power plant to run and produce electricity, various categories of mechanical, electrical, and chemical equipment in each category must be placed into operation to perform its intended function.发电厂运行发电，需要运行大量不同种类的机械、电气和化学设备，The operation of the equipment must be coordinated to meet the demand of the electricity production proce, and the production proce must be regulated so that the cycle and the equipment are operated within design conditions.设备运行必须按照电力生产过程的要求进行，生产过程应按设计工况调节工质循环与设备运行
The plant control system provides the neceary tools to enable the operators to orchestrate plant operation for the reliable and efficient production of electricity.机组控制系统能够使运行人员可靠而高效地组织电厂生产运行
This chapter provides an overview of the plant control system, its functions, operation and the type of control equipment used in a modern pulverized coal-fired power plant.本章介绍现代燃煤电厂的控制系统概况、功能、运行和典型设备操作。
6.2 Basic Control Functions
6.2 基本控制功能
In a modern power plant, the majority of the control actions required to operate the procees is automated.在现代的发电厂，大多数运行控制与操作是自动的。
There are numerous reasons for plant automation.电厂之所以采用自动运行有以下理由：
Firstly, automation reduces human error in plant operation and thus provides greater safety for plant personnel.第一，自动化可以减少人员在运行中误操作，对电厂人员安全提供更大的保障；
Secondly, automation reduces the number of operators required to run the plant, which reduces labor costs.第二，自动化减少了运行人员的数量，降低了人工费用； Thirdly, an automated proce is more efficient than a manual proce because automatic controllers are capable of responding to changes in operating conditions faster and more accurately than human operators.第三，自动化生产过程比人工操作效率高，自动控制系统能够比人更快更准确地应对运行中各种情况变化
The result is tighter control of plant operating parameters which keeps the proce running within design conditions.自动运行使电厂运行参数更加接近于设计工况。
33-3
The control functions used in operating a power plant can be claified in many ways.电厂运行的控制有许多分类方法，For the purpose of this discuion, the functions of the plant control system are claified by type of control action used.为便于讨论，控制系统的功能可按控制功能分类
In this respect, control functions can be categorized into two distinctively different categories: on-off control and modulating control.这样，控制功能可分为两种截然不同的类型：启停控制和调节控制，Both types of control functions can be found in a power plant.这两种控制在电厂都有。
The on-off control is also known as digital control, binary control, discrete [离散] control, sequential control or motor interlocks.启停控制又称数字控制、二进制控制、离散控制、顺序控制及电机连锁。
Modulating control is some times called analog control, continuous control, or closed loop control.调节控制有时被称为模拟控制、连续控制、闭环控制。
No standard industry-wide terminology exists for these two types of control functions.这两种控制在各行各业没有统一的定义。
On-off control produces a control action that varies in discrete states.启停控制发出一个控制动作指令，An example of this type of control is starting and stopping motor.这类控制的一个例子是开启、停止一台电机。
The control system produces either a start command or a stop command, and the controlled equipment reacts to the command with two distinct outcomes: motor running or motor stopped.控制系统发出启动或停机命令，受控设备按命令来进行不同的动作：电机启动或电机停机。
No intermediate state exists between the ―running‖ and the ―stopped‖ state.在启、停状态之间没有中间状态。
教材 115页
Modulating control produces a control output signal with a magnitude that varies smoothly from one value to another.调节控制发出一个控制输出信号，该信号值从一个值连续变化到另一个值。
33-4 An example of this type of control is regulating water flow to a tank by adjusting the position of water supply valve.该类控制的例子是通过调整给水阀的开度调节到水箱的流量
The control action is continuously adjusting the valve position to maintain the water level in the tank at a desired point.控制动作连续调节阀门使水箱水位保持在要求位置。
The state of the valve is continuous in that the position of the valve can be anywhere between the fully closed and the fully open position.阀门状态是连续的，可以从全关到全开任一位置。
Using on-off and modulating control to operate a power plant may be compared to a person driving an automobile.采用启停和调节控制来运行电厂与开汽车类似，To start the car, the driver turns on the ignition key and the engine starts.This is on-off control.开车时，司机启动点火钥匙，发动机发动，Once the engine is started and the car is running, the driver controls the speed of the car by continuously adjusting the accelerator position whenever the car’s speed deviates from the desired speed.This is modulating control.这就是启停控制。当发动机发动后，汽车开动，只要车速与要求值有偏差，司机会连续调整油门使汽车速度连续变化，这就是调节控制。
A power operator goes through similar steps in operating the power plant.电厂运行人员在电厂运行时也进行类似步骤，The operator starts a pump motor, a fan motor, or some such equipment.启动给水泵、风机及其他设备
Typically, the operator waits until a pump is started and then increases or decreases the opening of a valve at the pump discharge to regulate the water flow through the pump.典型的步骤是：运行人员在给水泵启动后，按泵的出水流量增减阀门开度来调节泵。On some occasions, both actions can be applied to the same piece of equipment.在某些情况下，同一设备可接受全部指令
A case in point is a pump drive by a variable-speed motor.比如当泵由一台变速电机带动时
The on-off action is used to get the motor started, and the modulating action is applied to regulate the pumping rate by adjusting the motor speed.启停控制用来启动电机，调节控制通过调整电机速度来调节泵流量
33-5 The on-off and the modulating control action complement each other.启停、调节控制互相补充
In the case of an emergency or a desired shutdown, the on-off control can shut down equipment and put the proce in a safe condition ready for a restart.在紧急停机或正常停机时，启停控制能使设备停机，并使其保持安全状态以备下一次启动
6.3 Plant Operation from the Control Room
6.3 电厂主控室运行
Operator interface devices are the tools that a control room operator used to monitor and control plant operation.主控室操作台是运行人员用来监视与控制电厂运行的工具
This section provides a brief rundown of the activities related to plant operation from cold start to full load that require the operator’s attention and interaction with the plant equipment and systems.本节给出电厂运行的简要说明，包括从冷启动到满负荷运行时的注意事项与电厂设备和系统的相互影响。
From the standpoint of operator in the central control room, the equipment and systems fall into two categories: 从主控室运行人员的观点看，设备和系统分为两类： those controlled by a local operator, and those controlled by the control room operator situated remote from the equipment.就地操作和主控室远程操作。
The former are mostly the plant systems that serve more than one or all units in the plant, and their operation is either intermittent or the outputs do not vary directly with the megawatt output of the plant.前者大部分是厂内系统，服务1个或几个单元，它们的运行是间断的且与电厂的负荷没有直接关系。
Those in the latter category are the unit-oriented equipment that must be placed into service when the unit is running and their operation must be regulated as the unit load changes.后者是机组运行的主要设备，它们的运行随着电厂负荷变化而变。
6.3.1 Common system operation 6.3.1公共系统运行
After a plant is built, it is rare that a unit has to be started from a very ―cold‖ condition with every piece of equipment at standstill and every tank or veel empty.电厂建成后，很少出现机组从所有设备停机、空水箱的极“冷”态启动。
However, if this is the plant condition at the time of a unit start, the operating
33-6 personnel will have to get
教材 116页
these systems into operation before doing anything else.The following steps should be taken:如果启动时电厂机组处于这样的冷态，运行人员在其他操作之前必须运行一些系统，应采取以下步骤：
(1)Energize the plant auxiliary electrical distribution system by bring in power from an outside source and powering up the control systems.（1）首先从电网向厂用电和控制系统供电。
(2)Start the compreed air systems(both the station service and the control air system)（2）启动压缩空气系统（包括检修用气和控制用气）。
(3)Make water(plant service water and cycle makeup water)by first starting the plant raw water system(or well water system, as the case may be)with its aociated water treatment system.（3）启动电厂生水系统（如井水系统）及水处理系统制水。(4)Prepare coal handling and other material(such as limestone)handling system for service.（4）准备制粉系统及其他材料系统（如石灰）。
(5)Prepare the ignition fuel system, and if applicable, the auxiliary boiler fuel system for service.（5）准备点火燃油系统和辅助锅炉燃油系统。
(6)Produce auxiliary steam by starting the auxiliary boiler when the required fuel, water, and compreed air are ready, or by taking steam from other sources if available in the plant.（6）当所需煤粉、软化水和压缩空气制备好后，启动辅助锅炉生产辅助蒸汽，也可从电厂其它蒸汽源获得。
Typically, plant common systems are installed with a control cabinet or a local control panel located in the vicinity of the system equipment(in some plants, the local control functions are selectively duplicated in the control room).典型地，电厂公共控制系统布置设备附近的控制柜或控制板，有些主控室也同样布置与就地控制板功能相同的控制柜。
While the systems are in operation, the major task for the central control room operator is to monitor the status of these systems.这些系统运行时，主控室运行人员主要任务是监控这些系统的参数。
33-7 As a rule, abnormal operating conditions of each system are alarmed in the central control room in the form of a ―system trouble‖ alarm for the control room operator to call on the local operator to investigate the trouble.通常，系统运行不正常时会在主控室发出“系统故障”的警报，主控室通知就地人员检查故障。
In addition, all equipment status information can be made available in the control room through the data highway of the equipment control systems(PLC or DCS).另外，通过设备控制系统的数据通道（PLC 或 DCS）主控室可获得全部设备运行参数的信息，The key to this monitoring function is to constantly check the major parameters such as coal silo [音标sailou] level, water tank level, and compreed air preure to ensure that each of the common systems is running at a capacity sufficient to support the needs of operating units in the plant.监控功能的关键是定期检查主要参数，如煤粉仓位、水箱水位、压缩空气压力，来保证公共系统能够充分满足电厂主机运行的需要。
6.3.2 Unit system operation A unit may be started as soon as the common service systems are operational.A myriad of activities will be conducted during a unit startup, some in parallel and some in sequence.6.3.2单元系统运行
公共辅助系统运行后单元机组即可启动，在一台单元机组启动时有大量的操作要执行，有些同时进行，有些按顺序执行。主要操作列举如下：
Preparation(1)Air Blow Startup 准备工作（1）空气吹扫启动
Air blows are a relatively new technology in the power plant construction industry.在现代电厂中空气吹扫是一项相对新一些的技术
The use of air blows must be worked into the schedule early in the preparation proce, to ensure proper cleanline specifications are iued to all vendors supply portions of the steam generation system.在准备过程中，应用空气吹扫必须及早做好计划，对蒸汽发生系统确保清洁。
33-8 Mill scale must be completely removed and proper welding techniques must be employed during the erection of the piping in preparation of air blows.Mill scale removal在空气吹扫系统管路建立过程中应采用正确的焊接技术，氧化皮须彻底清除，教材 117页
utilizing a chemical cleaning is often recommended to ensure the surfaces are adequately prepared for the air blows.一般推荐采用化学方法清理氧化皮，保证管道内表面合格以备空气吹扫。
A solid paivation layer on the piping will prevent flash rusting during the air blows.管道表面坚固的钝化层可避免在空气吹扫时生锈。
It should be noted that air blows are the only method available to achieve a cleaning force ratio or disturbance factor above 1.2(industry standard)in the superheaters of the boiler.应注意的是空气吹扫是唯一能够在锅炉过热器获得清洁力比或干扰因数大于1.2（工业标准）的方法，Manufacturers of boilers and HRSGs discourage steam flow rates during steam blows that would allow for carryover of moisture from the drum to the superheaters.电站锅炉和余热锅炉厂家从汽包到过热器设置节流板降低蒸汽流量，避免水蒸汽把水珠从汽包带到过热器。
As a result of this, steam flows through the superheaters cannot be greater than maximum normal operation.这样做的结果是蒸汽流量不会超过正常运行的最大流量，Air blows do not have this limitation and thus provide much more effective cleaning of the superheaters.空气吹扫没有这个限制，能够对过热器提供效果更好的清洁。
A comprehensive engineering analysis of the plant design is needed to ensure the feasibility of air blowing.一个完整的电厂设计需要保证空气吹扫的可行性
The engineering study must reveal the preure required to achieve proper disturbance factors, pump up times, blow down times, required exit piping sizes, disturbance factors in all portions of the flow path and the order in which the piping systems should be blown.工程分析必须提出所需的压力，以获得适当的干扰因素、加压次数、泻压次数、必需排气管尺寸、在所有流程的干扰因素、管道吹扫的次序。
The use and selection of the proper equipment is mandatory.必须使用和选择合适的设备，Oil free air compreors, boosters[升压机] capable of easily achieving the required
33-9 blow preures, air drying and cooling provisions should also be included.Heavy wall piping with full thickne and preure rate flanges, heavy-duty blow-down silencers with debris containment systems and fast acting valves are also part and parcel of air blows.如无油空气压缩机、升压机（能够较易获得所需的吹扫压力），也包括干燥空气、冷却空气的制备、带有高压法兰的厚壁管、带滤网大负荷排空消音器、快速阀。
(2)Steam blow start up（2）蒸汽吹扫启动
Exhaustive steam blows have been utilized in the industry for over 75 years, and was once the standard approach to cleaning steam circuit.全面蒸汽吹扫应用于工业已有75年之久，曾经是清洁蒸汽循环管路的标准方法
This method is similar to the exhaustive air blow technique, except the boiler is fired to generate the preurized steam used to clean the steam path to the turbines.该法与空气吹扫技术类似，不同之处是锅炉点火产生高压蒸汽清洁锅炉到汽轮机的蒸汽管路
Specialized high temperature quick-opening valves for the technique is provided, as well as detailed procedures and design of temporary piping, steam quenching devices, silencers and debris containment equipment.使用高温快开阀，设计临时管路、蒸汽淬火装置、消音器及滤网。
The highly trained Field Supervisors direct plant personnel in the conduct of this method, providing and operating target insertion devices used to aes the final cleanline of the steam circuit systems.专家应指导电厂运行人员吹扫操作，正确操作靶板来评估蒸汽循环管路的最终清洁度。
Over 20 years ago, the continuous low-preure steam blow technique was introduced, which has become standard practice for the pre-commiioning cleaning of steam system circuit.20多年前，引入了连续低压蒸汽吹扫技术，它已经成为试车前蒸汽循环管路清洁的标准程序。
This method provides for the steam generators to be continuously fired to generate steam velocities that are 7~15 times greater than the velocities generated during normal plant operations.这种方法使得管路中的蒸汽速度比机组正常运行时高7-15倍，Although the method requires the steam generators to be fired, it is also provides the plant operator the opportunity to commiion many plant auxiliary systems that require steam cleaning.33-10 尽管蒸汽吹扫要求锅炉点火运行，它能够给运行人员机会操作要求蒸汽清洁的许多辅助系统。
(3)Chemical clean and paivation The initial cleaning of a new boiler or pipe-work is critical to its operational succe.Added cost grows rapidly with no or poorly applied chemical cleanings.（3）化学清洗和钝化
一台锅炉或一套管路系统的最初的清洁对成功运行至关重要，没有清洗或清洗不够都会使机组今后的运行成本大幅增加。
Chemical cleaning removes inorganic residue such as rust, silica and millscale, utilizing化学清洗利用特殊配制的药剂去除诸如铁锈、硅石、氧化皮等无机残渣
教材 118页
chemical compounds which are determined by the need of user’s specific project.Typical chemical cleanings involve the use of tri-sodium phosphate / di-sodium phosphate , which gently scrub the residues from the interior of piping, tubes and other interior boiler surfaces.典型的是使用磷酸三钠/磷酸二钠清洗管路，能从管路内表面、其他锅炉容器内表面逐渐去除残渣。
Failure to remove this inorganic residue results in pitting and further corrosion and eventually, tube failure.不清洗这些无机残渣会导致侵蚀和腐蚀，最后导致爆管。Recent investigations of tube failures on relatively new HRSGs have shown that on some units, heavy deposits of scale are located at the tube to header weld area[音标airiea].最近一项锅炉管路失效研究表明，在某些机组管路到联箱的焊缝处积垢严重。This localized heavy corrosion is the result of the localized post weld heat treatment of the tube to header welds.这种局部严重腐蚀是从管路到联箱的焊缝局部热处理的结果，It is common practice for HRSG fabricators to locally heat-treat these areas of the harp sections to avoid exceive corrosion of the finned surfaces of the tubes.对余热锅炉厂家来说在竖管部分进行局部热处理以避免管路的鳍片内表面过度腐蚀的方法是常规措施
The presence of the deposits may result in reduced natural circulation in the tubes and may also provide a site for under scale corrosion.严重的积垢会导致自然循环流量减少及垢下腐蚀。
33-11 When such localized heavy deposits of mill scale are present, special care must be taken during chemical cleanings to insure that sufficient chemistry and contact time is provided to completely remove these deposits.当这样的局部腐蚀物出现时，在化学清洗中须特别关注它，保证足够的药品接触时间和剂量以全部清除这些沉积物。
Chemical analysis is followed by the engineer’s determination of the best cleaning method and appropriates chemistry for complete cleaning.化学分析后，工程师确定最佳的全面的清洗吹扫方法，Chemical cleaning is followed by paivation of the surfaces.Sometimes a nitrogen base, sometimes paivation takes another chemical form.清洗后管路表面进行钝化，钝化层有时采用氮基，有时是其他化学形式。
(4)Hydrostatic Testing（4）水压试验
During hydrostatic testing, all high points are targeted to ensure complete water fill, eliminating the small air pockets by utilizing rapid fill rates.在水压试验中，管路高处应保证充满水，提高加水速度可减少气泡的滞留。
Secured hoses are connected to high points to allow water to flow through high point valves, and directing exce test water away from exposed insulation that not yet been covered by cladding.[包裹层]
将牢固的软管接到管路高处就地阀门注水，避免管路溢水在没有覆盖的绝缘上。
Test water is often run through partially open valves to ensure contamination is removed from seats and seal prior to preurization, since many valve seats will be contaminated initially with dirt and debris.为了加压，水从半开的阀门流出，将阀座和先前密封处的污物带出，因为许多阀座最初被污垢和碎屑污染。
If vent or drain piping is plugged with debris, sections of the system may not fill properly, therefore this preliminary testing is vital to succeful hydrostatic tests.如果管路出口被碎屑堵塞，有些系统注水不满，因此这个初步的试验对水压试验的成功非常重要。
Once sealed, it is often beneficial to perform preliminary pneumatic test at preures below 25 psig to identify valves and fittings that have not been adequately tightened, or have exce debris in seals and seats.一旦密封，进行初步的25 psig压力下
33-12 的空压试验有益于确定阀门和附件是否关闭严密及阀座、密封是否有碎屑。
Valves that have not sealed under preure may have their seats cut by high preure water, leaking valves are opened to flush contamination before the valve is resealed to stop the leak.承压下未密闭的阀门其阀座会被高压水冲刷，阀门打开排污后阀门重新关闭停止泻流，Hydrostatic test water is filtered to remove the solid contaminates that are often present in new plants.水压试验注水清洗掉新机组内常有的固体污物。
Since the solubility of air in water increases with preure, small air pockets will slowly diolve into preurized test water, which will typically result in a slow lo of preure as void is filled with water.因为空气的溶解性随着压力的升高而增加，小气泡会慢慢地溶解于高压水中，当管内的空间充满水后它将导致压力的缓降。
Good practice allows for this phenomenon by slow preurization and adding additional water, as required, to maintain test preure.好的做法是按要求缓慢加压并加水以保持水压。
Ice is also a dangerous threat to a new HRSG, so complete draining will follow hydrostatic testing to prevent damage to preure parts.结冰是新余热锅炉的一大威胁，因此水压试验后应排干水以避免损坏承压部件
Ice can plug and damage new drain and
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vent piping, and can ruin valve seals, so attention to drainage following hydrostatic testing is carefully engineered into all procedures related to this testing.结冰能堵塞和损坏排水、排气管路、阀座，所以要注意水压试验后进行排水统，这是锅炉水压试验必不可少的部分。
Starts Starts are usually categorized as cold, warm or hot stars.The definitions vary between utilities and units and are influenced by the extent to which heat is retained in the unit and the controllability of the plant.Starts are typically categorized as: 启动
启动经常分为冷态启动、温态启动、热态启动。该定义受以下因素影响：机组、机组蓄热量、机组操控性等。启动大致分为以下几类：
33-13(1)Hot start---(400℃(Fig.6-1).(2)Warm start---(> 8 hours), 200 ℃(Fig.6-2)(3)Cold start--->72 hours shutdown and turbine metal temperature 400℃（见图6-1)。
（2）温态启动──停机> 8小时, 200℃（见图6-2)。（3）冷态启动──停机>72小时，汽轮机金属温度
图6-1 1000MW超超临界机组热态启动曲线
MST 主蒸汽温度；RST 再热蒸汽温度；MSP 主蒸汽压力；parallel in 并网；turbine in 汽轮机冲转；L/min 满负荷/min；
Guidance from the original equipment manufactures(OEM’s)for traditional base load units is likely to have been very conservative with a typical cold start time of 12 to 15 hours and 3 hours for a hot start for a large machine.设备制造厂家保守地认为一台带基本负荷的大机组冷态启动时间为12到15小时，热态启动时间至少为3小时。
Economic two shift operation requires that units are brought back on load and taken off load as quickly as poible to minimize off load heat costs.从经济上讲两种运行方式（带负荷和降负荷）应越快越好，以尽可能减少热损失
This action has to be balanced against the obvious effects of induced thermal strees resulting in costly plant failures.这种操作应平衡考虑引起热应力的明显效应，从而影响机组的寿命。
Unit Operation(1)start the circulating water system(2)Fill the water tanks and veels(such as the boiler drum, condensate storage tank, condenser hot well, and de-aerator storage tank)with treated water.(3)Place the condensate system into service by starting the condensate pumps.单元运行
（1）启动循环水系统。
（2）向水箱、容器添加处理合格的水（如锅炉汽包、凝结水贮水箱、凝汽器热井、除氧器水箱）。
（3）启动凝结水泵开启凝结水系统，教材 120页
33-14 图6-2 1000MW 超超临界机组温态启动曲线
Shutdown 停机；
图6-3 1000MW 超超临界机组冷态启动曲线
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Because there is no demand for condensate at this time, the condendate flow will be re-circulated from the pump discharged back to the condenser.因为此时不需要凝结水，凝结水由凝结水泵驱动在系统内自循环。
(4)Use the auxiliary steam to peg [固定] the de-aerator at a predetermined preure.(5)Place the feed water system into service by starting the boiler feed pump.Because there is no demand for feed-water at this time, the feed water flow will be re-circulated from the pump discharge back the de-aerator.（4）用辅助蒸汽确定除氧器的预定压力。
（5）启动给水泵开启给水系统，因为此时不需要给水，给水由给水泵驱动在除氧器系统自循环。
(6)Start the turbine lube oil system;put the turbine on turning gear and use auxiliary steam to heat the turbine and pull vacuum on the condenser.(7)Open all the boiler dampers, start the air heaters, include draft fans, and forced draft fans, and commence the furnace purge.（６）启动汽轮机润滑油系统，开启盘车，用辅助蒸汽加热汽轮机，凝汽器开始抽真空。（7）打开锅炉风道挡板，启动空气预热器、送风机、引风机，进行锅炉冲洗。
(8)Initiate boiler firing after completion of the furnace purge by starting the required number of igniters for lightoff [点火], and start the first pulverizer group following the succeful lightoff.(9)Warm the steam line as steam is produced from the boiler.（8）锅炉冲洗合格后，启动燃烧器进行锅炉点火，成功点火后启动第一组磨煤机。（9）锅炉产出蒸汽后进行暖管。
(10)Open the turbine steam admiion valves and roll the turbine off the turning gear as the boiler steam condition matches the turbine metal condition.(11)Increase the turbine speed to the generator synchronous speed(3000 r/min)
33-15 through the turbine control system and hold the speed for turbine heat soak [浸泡] if neceary.（10）打开汽轮机主汽阀冲转，当锅炉蒸汽与汽轮机金属情况匹配时，切除盘车。（11）通过调速系统汽轮机升速至发电机的同步转速（3,000 rpm)，如有必要则定速等待汽轮机膨胀。
(12)Start the generator excitation system, synchronize the generator and put the turbine-generator unit on minimum load.(13)Increase the unit load by increasing the boiler firing rate, and put additional burners(and pulverizers)and other auxiliary equipment(fans and pumps)into service as the unit load increases until the unit reaches full load.（12）启动发电机励磁系统，发电机并网，使汽轮发电机组带最低负荷。
（13）通过加大锅炉负荷（增加燃烧器、磨煤机、风机和泵的负荷）提高机组负荷，直至机组达到满负荷。
Startup and online operations involve a variety of plant systems.启动和并网运行涉及电厂各个系统
The operating procedures are automated to a varying degree.运行过程不同程度地自动进行
The basic concept of CRT-based operator interface functions is to develop displays revolving around the individual plant systems, starting with a system overview followed by proce graphic displays and supplemented with faceplate, bar graph, and trend displays of pertinent parameters.屏幕操作界面的基本功能是巡回显示电厂各个系统，初始界面是一个图示的系统全貌，由相关参数柱状图、趋势线组成Similar displays can be made and fuel flow paths piece of equipment such as a pulverizer, with a diagram showing the air and fuel flow paths in the pulverizer, measuring points, and damper drives, accompanied by bar chart, faceplate, and starting permiive displays.大量的单个设备（如磨煤机）也可类似地显示，图示出空气和燃料流程、数据测点、挡板驱动、启动允许参数
The supplementary displays can further be overlaid on the graphic display.图上可加入一些辅助的数据显示
The idea is to have the displays organized so that they can be easily and quickly called up as the need arises.显示图设计成又快又容易调出所需数据，With a CRT-based console, the operator remains in a seated position while
33-16 performing his or her duties.在屏幕控制台前，运行员坐着操作，All information and data gathered in any proceor are available for the operator to make decisions about the control actions neceary during operation and particularly under emergency circumstances.可以在运行时随时调出每个操作的数据信息以便决定操作（特别是在紧急状况时）
Alarms are treated separately.New alarm meages take precedence over other displays and preempt the current displays if needed.警报被分类处置，新警报信息优先显示。
Printed logs also play a role in helping the operator.Typical usage includes periodic logs 运行日志也扮演着重要角色，典型的日志包括用定时日志
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(hourly, daily, etc.)to collect routine information, alarm log to check alarms in recent past, trend log to trend variable(for example, turbine metal temperature during startup), sequence of log to determine the cause of a trip, and post-trip review log to examine the behavior of major equipment in the period immediately before and after a trip.（每小时、每天等）收集日常信息，警报日志核对近期警报，趋势日志表示变量的趋势（如启动时汽轮机金属温度），事故日志确定故障和事故的原因，机组跳闸日志确定跳闸前后主要设备的操作。
Data collected by the long-term data storage equipment are not just for the operator.大容量存储器收集、存储数据不仅是为了运行人员，The data represent the operating history of the various pieces of plant equipment(running time and number of starts, etc.)and the status of machine health(for example, trend of metal temperature or bearing vibration over time), and are used by the plant maintenance personnel as a reference to develop preventive maintenance programs for the plant equipment.这些数据记录了电厂各个设备的运行历史（运行时间、启动次数等）、机器设备的健康状况（如金属温度趋势、轴承超时振动），它还可帮助检修人员针对电厂设备制定预防保养措施，This application will increase as the data collection and analyzing techniques of the DCS become more sophisticated.随着DCS数据收集和分析技术日臻完善这些数据更具价值。
33-17
6.4 Burner Operation 6.4 燃烧器运行
The most critical consideration in operating the fuel burning equipment of a boiler is the hazard of furnace explosion.在运行锅炉燃烧设备时最主要考虑的是炉膛爆燃的危险，A furnace explosion can cause catastrophic damage to the boiler equipment and endanger the safety of plant personnel.炉膛爆燃会对锅炉设备造成灾难性的损坏，并且危及电厂运行人员的安全。
The most likely cause of a furnace explosion is the spontaneous and rapid combustion of any accumulated unburned combustibles in the furnace or along the flue gas path of the boiler.炉膛爆燃最主要的原因是炉膛内或烟道内堆积的未燃煤粉自燃及快速燃烧，当超量未燃煤粉与空气混合时，气粉混合物达到爆燃浓度，遇到足够电荷点火能量、热渣或意外引入炉膛的火星就会发生爆燃。
The explosive combustion is likely to occur when an exceive quantity of unburned combustibles is mixed with air and the mixture reaches an explosive proportion in the presence of sufficient ignition energy from electric charges, hot slag, or sparks inadvertently introduced into the furnace.爆燃容易发生在下列情况：多于的可燃物质积累并与空气混合，混合物浓度达到爆燃范围，来自放电、热渣、电弧等足够的点火能量。
Operating experience shows that such an accumulated mixture is often the result of idle burners, sudden lo of burner flame during operation, or any other situation that can poibly result in such a situation must be prevented and any combustibles present must be burned or completely purged from the furnace.运行实践表明：多次试图点炉失败、煤粉从非工作燃喷燃器漏入炉膛、运行中灭火及大量煤粉混合物进入炉膛的任何其它情况都会产生超量气粉混合物。因此，应避免以上情况的操作，现有的煤粉须燃尽，未燃煤粉须彻底从炉膛清理掉。
Every burner control system is designed with the considerations in mind.每个锅炉控制系统在设计时就充分考虑了这一点。
The burners in a multiple-burner furnace are grouped for operation according to their physical location in the furnace.在多喷嘴炉膛燃烧器按炉膛实际结构布置 The boiler manufacture’s particular design of a furnace will dictate [规定] whether
33-18 the burners in a burner group will be operated singly, in pairs or as a group.锅炉制造厂家对炉膛的特别设计规定了燃烧器是否单独运行、成对运行还是成组运行
Operating a burner involves manipulating the fuel valve, air register(damper), igniter, ignition fuel valve, and other acceories aociated with the burner.燃烧器运行包括熟练操作煤粉阀、调风器（风门）、点火器、燃油阀和燃烧器其它相关附件。
At the group level, operation involves starting and stopping the equipment common to the group.燃烧器成组运行包括启停该组公用的设备
For a pulverized coal-fueled boiler, the group equipment includes the feeder(s), pulverizer, primary air fans and air dampers around the pulverizer.对煤粉炉，这些设备包括给粉机、磨煤机、一次风机、磨煤机周围的风门。
The operation of the various components in the group must be coordinated to ensure that fuel and air are admitted into the furnace through the burners in proper order and in correct proportion to avoid the 燃烧器组内各部运行必须协调，以保证喷嘴喷入炉膛风粉浓度合适，教材 123页
accumulation of any unburned combustibles and without unwanted ignition source.The procedure must be repeatable and indentical [完全相同的] for all the burners, which makes it very conductive to the application of a sequential control logic.避免煤粉未燃尽或煤粉太少。运行规程对所有燃烧器应统一、可重复，这样有益于连续控制的应用。
A typical burner control system consists of three parts: burner control, matter fuel trip, and furnace purge operation.一个典型的燃烧器控制系统由三部分组成：燃烧器控制、主燃料跳闸控制、炉膛吹扫。
The burner control portion of the system involved the starting and stopping of the individual burner or burner groups.For a pulverized coal-fired boiler, typical burner start operation is as follows: 燃烧器控制部分包括单个或成组燃烧器的启停，煤粉炉燃烧器运行的典型步骤如下：
Check the secondary air flow is adequate. Put the air register in the light-off position. Check that the ignition fuel supply is available..检查二次风量合格。.将风门调至点火位置。
33-19.检查点火燃料可用。
Initiate the spark or other ignition source. Place the igniter into service by opening the ignition fuel shutoff valves. Check the ignition flame and shut down the igniter if the flame is not detected within a specified time period..启动点火器或其它点火装置。.打开点火燃料关断阀点火。
.检查点火火焰，如果未发现火焰，应在规定时间内关闭点火器（如果第一台磨煤机投运则应启动主燃料跳闸）。
Check the primary air flow is adequate. Open the coal valve on the coal pipelines from the pulverizer to the burners being started. Start the pulverizer..检查一次风量合格。
.开启从磨煤机到喷燃器煤粉管道的阀门。.启动磨煤机。
Start the coal feeder. Check the coal flame and shut down the burner and igniter if the flame is not detected within a specified time period..启动给粉机。
.检查煤粉火焰，如果未发现火焰则在规定时间内切断燃烧器和点火器。
The operation is considered succeful when the main(coal)flame is detected within preset time period.In general, the igniters are kept in operation during low load operation to help maintain flame stability in the furnace.They can be shut down at the operator’s discretion [考虑] when the boiler load reaches a certain minimum level and there is sufficient turbulence to enhance flame stability.在规定时间内监测到主火焰即认为点火成功，为了炉膛燃烧稳定，在低负荷时点火油枪继续投运。锅炉升至一定负荷时，燃烧稳定维持，油枪即可退出关闭。
33-20 The burner control system is designed for remote operation from the central control room of the plant.燃烧器控制系统设计成在电厂主控室远程操作
The sequence can be operated in either manual or automatic mode.运行模式可手动或自动
In the manual mode, the operator initiates each step of the sequence.在人工控制模式，运行人员需执行每一步操作
In the automatic mode, the operator needs only to initiate the first step and the system logic automatically cycles the equipment through the remaining steps.自动模式中，运行人员只需执行第一步操作，系统会按程序执行其余的步骤
In either case, the logic checks the permiive for each step before it is allowed to proceed to the next step, and the sequence is stopped automatically if any prescribed unsafe operating conditions are detected.不论哪种模式，执行下一个步骤前程序都会对每一步的正确性检查
Similarly, a shutdown sequence is also provided.如果有规程规定的不安全操作情况出现，程序会自动停止，同样可以停机。
Typically, an operator panel with push buttons and indicating lights or a CRT-based control is provided for the operator to select the manual or automatic mode, 带按钮和指示灯的操作台或操作屏幕可以让运行人员选择是手动还是自动模式
and to initiate each step when in the manual mode(with all feedback information displayed to show the status of，在手动模式启动每一步骤时，教材 124页
the components and the system).反馈回来的参数会显示系统和设备的状态。
The key to safe burner operation is to shut off the burner immediately at the slightest indication of any accumulation of unburned combustibles or if ignition energy is insufficient to sustain the fuel burning proce.燃烧器安全运行的关键是在有即使是轻微的未燃煤粉堆积或点火能量不足以维持煤粉稳定燃烧时立即关闭燃烧器
No practical means exists to monitor the accumulation of unburned combustibles or the ignition energy.但是现在无法监控未燃煤粉的堆积或点火能量
Its existence can only be inferred from the lack of burner flame when the fuel is being admitted into the furnace through the burners.现在只能从看到煤粉从燃烧器喷入炉膛后火焰熄灭推断
33-21 A ―flame detected‖ or ―no flame detected‖ condition for a burner is an indication of whether the fuel admitted is being burned or not.火焰存在与否确切表示煤粉是否燃烧 For this reason, flame detection plays a vital role in the functioning of burner control system.正因为如此，火焰监测在燃烧器控制系统中扮演着至关重要的角色 A variety of techniques exist for flame detection.The detectors used for utility boilers are those sensing the light emitted by the burning fuel(ultraviolet and infrared detectors)or the flickering frequently of the light produced by the burning proce(flicker detectors).现有多种技术进行火焰监测，电站锅炉使用的火焰监测器是监测煤粉燃烧火焰的光线（紫外线和红外线探测仪），或是监测燃烧过程火焰光闪烁频率（闪光探测仪）
The selection is largely dependent on the type of fuel burned, burner design, and the particular design consideration of the boiler and the burner control system.选择那种监测技术取决于燃煤品种、燃烧器型号及锅炉、燃烧器控制系统的特殊设计考虑。
In general, igniter flame is monitored on an individual basis.一般而言，点火火焰分别监控。
The monitoring philosophy for main flame varied depending on the firing pattern of the boiler.主火焰的监控方法因锅炉的不同燃烧形式而变化。
In a wall-fired furnace, a detector is typically installed for each burner.在墙式炉膛，典型地为每一个燃烧器配监控。
In a tangentially fired furnace, the detectors are shared between burners on adjacent elevations.在四角切圆燃烧炉膛，相邻的燃烧器公用监控。
The main flame is monitored either on an individual or group basis depending on the manufacturer’s arrangement of the burners.主火焰可按生产厂家的设计单独或分组监控。
6.5 Preure Operation 6.5 压力运行操作
Constant preure operation consists of operation at a constant throttle steam preure over the entire load range.定压运行指在整个负荷范围内保持蒸汽压力恒定 Variable preure operation is defined as controlling the boiler steam production by controlling and adjusting the boiler steam preure.变压运行是指通过控制、调节锅炉主汽压力来控制锅炉出力
33-22 Eentially, the turbine throttle valves are left in an open position and steam flow is increased or decreased by increasing or decreasing the throttle steam preure.原则上，汽轮机进气阀处于全开状态，进汽的增减由升降气压控制。
Variable preure operation is further divided into two types: pure variable preure and hybrid variable preure.变压运行进一步分为两类：纯变压运行、混合变压运行 In pure variable preure, the turbine throttle valves are wide open and any load reduction below maximum continuous rating is achieved by steam preure operation over the upper load range and variable preure operation over the lower load range.在纯变压运行中，汽轮机进气阀全开，低于最大连续负荷的工况变化由调节汽压完成。混合变压运行中，机组高负荷时定压运行，低负荷时变压运行。
The benefits of variable preure operation are improved turbine cycle efficiency and improve boiler steam temperature control range.变压运行的优点是它提高了汽轮机循环效率、加大了锅炉汽压的控制范围
Part-load turbine cycle efficiency improves as a result of reduction of high-preure turbine throttling valve loes.高压汽轮机进气阀气压损失的结果是提高了部分负荷汽轮机循环效率
The reduction of throttle valve loes results in higher steam temperatures through the high-preure turbine, higher high-preure turbine exhaust(cold reheat)steam temperature, and therefore an improvement in reheat steam temperature control range, since the cold reheat steam is hotter
教材 125页
than it would otherwise be with constant preure operation at the same steam flow.提高高压缸进汽压力和排汽温度（再热冷段），因为再热冷段温度比定压运行相同蒸汽流量时高，改进了再热蒸汽温度控制范围，这样就可降低进气阀气压损失。
Variable preure operation can be achieved either by control of firing rate during operation, or through the use of large division valves in the intermediate superheater flow connecting links.(Fig.6-4 is a flow diagram that includes division valves.)变压运行可由控制燃烧负荷或调节中段过热器管道阀门实现，图6-4是含阀门的流程图
Variable preure operation through control of the firing rate is accomplished by changing the firing rate prior to changing the load, or steam flow.变压运行中在变机组负荷和蒸汽流量前改变燃烧
If a load reduction is desired, then the firing rate is reduced without moving the
33-23 turbine throttle.如果想降机组负荷，只需降低燃烧负荷，不必变动汽轮机主气阀开度 As energy delivery to the steam system is reduced, the drum temperature, steam preure, and steam flow decrease.因输入蒸汽系统的热量减少，汽包温度、气压及流量降低
As the desired lower load is achieved, the firing rate is stabilized, drum temperature and preure stabilize, and a reduced steam flow is established.For an increase in load the firing rate is increased and the effects are reversed, which results in an increase in steam flow.当机组负荷降到目标值后，稳定燃烧、汽包温度、气压、流量。机组增大负荷时，操作相反，加大燃烧负荷，最后增加蒸汽流量。
图6-4 全负荷启动系统
Division valve bypa 隔离阀旁路；
Control of steam preure by control of the firing rate is the least expensive and most widely used variable preure system.通过控制燃烧来控制蒸汽压力是最经济的，在各种变压系统中广泛运用
Control by firing rate has added benefit of a reduction of boiler feed pump power, since the drum preure and therefore the static preure requirement of the boiler feed pump are reduced during variable preure operation.控制燃烧的另一优点是降低了锅炉给水泵耗电，这是由于在变压运行中汽包压力和锅炉给水压力都降低了
Since the drum operates at full preure with a division valve system, the boiler feed pump power is not reduced.在分段阀系统微调压力时，锅炉给水泵功率不降低。
The division valve system is somewhat more responsive to load changes than a firing rate variable preure control system.对于负荷变化，分段阀系统在变压系统中比燃烧响应度高，With a division valve system, the firing rate is controlled to maintain drum preure.燃烧控制与分段阀系统一起维持汽包压力。
Load reduction valves are closed, the superheater outlet preure and flow are reduced.The drum preure increases as the division valves close and the firing rate is decreased, returning the drum preure to its original valve.When the boiler stabilizes at a reduced load, the drum preure returns to its original value, the division valve is in a throttled position, superheater outlet preure and flow are reduced, and the firing
33-24 rate is reduced
使用分段阀减少主汽流量来降低机组负荷，当分段阀关闭时，过热器出口压力、流量降低，汽包压力提高，燃烧降低，形成反馈使汽包压力回到原值。
教材 126页
to establish a balance with steam production energy requirements.The division valve action and effects are reversed to increase the steam generator load.The load change capabilities for the two variable preure systems are 2% of full load per minute with firing rate control, and 10% of full load per minute with a division valve system.当分段阀处于节流位置时，过热器出口压力、流量降低，燃烧降低以平衡蒸汽生产所需热量的减少，分段阀的功能作用与提高机组负荷相反。对于调整燃烧的两类变压系统，机组负荷变化能力为每分钟2%的满负荷，分段阀系统的加入可使变化扩大至10%满负荷。
An additional benefit of variable preure operation and higher steam temperature is the ability to trip the turbine at a higher temperature on shutdown.If the turbine is subsequently restarted from hot conditions, the resulting thermal cycle of the turbine components is reduced.变压运行和提高主汽温度的另一好处是能够在较高温度汽轮机打闸停机，如果汽轮机随后从热状态启动，其结果是汽轮机的热力循环周期缩短。
Because of the turbine heat rate and steam temperature control range improvements that can be obtained, variable preure capability typically is recommended as a design feature for new utility steam generation units.因为汽轮机温升速度和主汽控制范围的改进，变压系统是电站新机组的一个设计特点。
Preure control: main steam flow and hence generated load is effectively controlled by setting the steam preure.压力控制：通过压力控制对蒸汽发电负荷进行有效地控制，这可以通过以下几种措施进行：
This can be achieved by either(1)throttling the steam flow by modulating the governor(or throttle)valves of the turbine while maintaining constant upstream conditions;(1)当阀前定压时调节汽轮机主汽阀（调节阀）以控制主汽流量
(2)varying the steam preure ahead of the turbine;(2)先于汽轮机改变主汽压力 or(3)some combination of the above.For the latter two, the preure set point is adjusted so that the throttle valves operate at valve points, i.e.where no valve is
33-25 partially open.(3)前两者结合。对后两者，压力调节点已调整，这样调节阀在阀点运行，即没有阀门是半开的。
Power plants can operate in sliding-preure, constant-preure or modified sliding-preure mode which lies somewhere between the first two.The operating mode has a bearing on both the design and material stre of the components, as well as the dynamic behavior and efficiency of the unit.电厂能进行滑压运行、定压运行或介于二者的改进滑压运行，运行模式取决于电厂设计、部件材料应力、机组的动力性能及效率。
Constant Preure Operation: When in automatic mode, operation will always try to control turbine throttle preure to set point.It will normally control throttle preure by adjusting the fuel firing rate(boiler flow mode)or, in unusual circumstances, by modulating the turbine governor valves(turbine follow mode).定压运行：在自动模式，运行总是来控制汽轮机调节阀，它通常调节燃烧强度来控制调节阀压力（锅炉跟随模式），在非正常情况下调整汽轮机主汽阀（汽轮机跟随模式）。
Sliding Preure Operation: In sliding preure operation, the throttle preure set point(and therefore throttle preure)is varied to achieve load demand while the turbine throttle valves are controlled to wide open position(VOW—Valves Wide Open).The primary advantages of this mode of operation are: 滑压运行：滑压运行中，当汽轮机调节阀全开时，调节阀压力位置（也即调节阀压力）随机组负荷要求而变，这种运行模式的优点主要有：
Reduced throttling loses from the governor valves increases turbine efficiency. Boiler feed pump power consumption is reduced at lower loads. Higher superheater temperatures at low loads improves turbine cycle efficiency.•减少主汽阀节流损失，提高汽轮机效率。•在机组低负荷时降低锅炉给水泵耗能。
•机组降负荷时过热器压力较高，提高了汽轮机循环效率。
A disadvantage of sliding preure operation is slow response time for the unit.The DCS has been configured to allow sliding preure operation but testing has not been conducted to develop the neceary set point curves and it is not utilized.33-26 滑压运行的缺点是机组的反应时间慢。
DCS系统设定成允许滑压运行，但是没有测试定出启动曲线前不能使用。
6.6 Startup Systems
6.6 启动系统
The purpose of boiler-internal startup systems is to drain off the exce water discharged 炉内启动系统的目的是从蒸发器排出未汽化水，教材 127页
from the evaporator and ensure flow through once-through evaporators.保证直流蒸发器流量。
Exce water is defined as the quality of water which must be remove from a water-filled heat-exchange system due to increased volume as a result of steam formation and increased temperature.这些水的定义是：当水在满液蒸发器中形成蒸汽并升温时体积膨胀而排出的部分。
Natural circulation and forced circulation boilers only have equipment for removing the exce water from the drum.自然循环锅炉和强制循环锅炉有从汽包排水的设备
During startup of once-through boiler, a circulation flow is combined with the once through flow in the economizer and evaporator until the minimum evaporator flow level.在直流炉启动中，最小蒸发流量循环流量由省煤器和蒸发器流量合并
The water that does not evaporate is separated from the steam in HP separators and then fed either to a recirculation pump, a drain heat exchanger, the feed-water tank or an atmospheric flash tank.未蒸发的水在高压分离器分出入再循环泵、排水换热器、给水箱或大气扩容器。
The unit startup system ensures cooling of the superheater heating surface and supplies steam to the turbine at the required startup preure and temperature.机组启动系统保证过热器受热面的冷却、在需要的启动压力温度时向汽轮机供汽。
In modern power plants, separate turbine bypa systems for the HP and IP/LP cylinders of the turbine, respectively, are seeing increased use.在现代化的火电厂，汽轮机高、中、低压缸分别有各自的旁路系统越来越多见。
Eential advantages of this system are the result of the uniform heatup of the
33-27 superheater heating surface-preventing flaking of the protective coating of on the inside of the tubes caused by thermal shock and carryover of corrosion products into the turbine(solid particle erosion)– short startup time, and the same basic startup procedure for cold, warm and hot stars.这个系统的主要优点在于使过热器受热面均衡受热，避免由于热冲击造成管路内表面保护层脱落而将固态腐蚀物带入汽轮机，缩短启动时间（不论是冷态、温态和热态启动）。
If bypa systems are dimensioned appropriately(>60% steam flow at full load), the steam generator can be kept in operation even when there is a turbine-generator load rejection to the station auxiliary power level, thus in most cases preventing a unit trip.如果旁路系统应用得当（> 60%满负荷时蒸汽流量），即使甩负荷时，锅炉可保持运行，这样在大部分情况下避免机组跳闸。
Steam generator startup involves firing with natural gas or fuel oil heat up the boiler.When combustion air temperatures are sufficiently high, coal firing is initiated.The principal firing rate constrains during startup are as follows: 锅炉启动包括用天然气或燃油点火加热锅炉，当燃烧温度足够高时，煤粉开始燃烧。在启动中燃烧速率主要受制于以下因素：
Heat transfer surface metal temperature. Heatup rate of thick-walled preure parts such as the drum and steam headers. Steam preure control. Temperature mismatch between steam and turbine metal.•换热器表面金属温度。
•厚壁压力容器的加热速率（如汽包、蒸汽联箱）。•蒸汽压力控制。
•蒸汽与汽轮机金属温度是否匹配。
During startup, when the steam flow is zero or very low and the cooling effect of the steam is limited, the superheater metal temperature is eentially equal to the flue gas temperature entering the superheater tube bank.启动中，当蒸汽流量为零或很低时蒸汽的冷却作用有限，过热器金属温度基本上等于进入过热器管箱的烟温。
During this early stage of the startup, the metal temperatures are monitored indirectly by measurement of the flue gas temperature with an air-cooled flue gas temperature probe in the upper furnace.在这个启动的早期阶段，金属温度由炉膛上部测量烟温的空冷探头直接监控。
33-28
The heatup rate of thick walled preure part is monitored with thermocouples.厚壁压力部件的加热速率由热电偶监控
Typical drum heatup rates range from 100ºF(56℃)/h on older boilers to 400 ºF(222℃)/h on a modern installation.典型的汽包加热速度旧锅炉为100℉(56℃)/h、现代化新锅炉为400℉(222℃)/h
Preure part temperatures must be monitored and the firing rate controlled to achieve an acceptable heat up rate.为获得理想的加热速率，承压部件温度必须监控，燃烧强度也要控制。
Several specialized systems are available to aid in steam temperature and preure control during startup.一些特殊系统在启动中对蒸汽温度和压力控制也有帮助
These systems include the superheater bypa, the reheater outlet steam attemperator, and the superhjeater outlet steam attemperator with secondary superheater stop，包括过热器旁路、再热器出口蒸汽减温器、过热器出口蒸汽减温器（教材 128页
valve and stop valve bypa.带二级过热器关断阀及关断阀旁路）。
6.6.1 Superheater bypa 6.6.1过热器旁路.The superheater bypa is startup system that provides a method of releasing steam and relieving drum preure during boiler startup without the lo of feedwater.过热器旁路是一套启动系统，它可以在锅炉启动中不损失给水的前提下释放蒸汽、汽包减压
On hot starts, including starts from following overnight shutdowns, the turbine metal temperature is high prior to rolling the turbine, and high steam temperatures are desirable to match the turbine metal temperature.在热态启动中，包括启动前夜停机的机组，汽轮机金属温度较高，高的金属温度要求高的蒸汽温度。
As the turbine is rolled, the firing rate and the gas temperature leaving the furnace have to be kept high to maintain high main steam and reheated steam temperatures.汽轮机冲转时，要保持较高的燃烧强度和炉膛烟温使维持高的主汽和再热温度。
This generally results in a rapid rise in throttle preure which is undesirable because of the resulting large temperature drop when steam is throttled acro the
33-29 turbine control valves.这一般会导致节流压力迅速上升，因为蒸汽通过汽轮机主汽阀时节流温度骤降。
The superheater bypa to the condenser provides a mean to maintain throttle preure in the range of 500 to 1000 psi(3.45 to 6.90MPa), and offers several advantages for hot restarts and starts following overnight shutdown:过热器旁路为凝汽器提供了措施，来保持3.45-6.90 MPa调节压力，对热态重新启动和隔夜停机启动都大为有利：
An optimum match of steam conditions and turbine metal temperatures at the maximum heat input to the boiler within the limits dictated by metal protection of the reheater and superheater.在最大锅炉热输入时保持最适合的蒸汽与汽轮机金属的温度匹配，并维持在再热器和过热器金属保护的限度内。
Reduction in startup time from improved turbine metal to steam temperature matching and increased heat input;and减少启动时间，因改进汽轮机金属与蒸汽温度匹配和提高热输入 Turbine starting with a greater opening of the turbine control valves as a result of the lower throttle preure, thus easing the temperature shock of the turbine first-stage(impulse stage)shell metals.汽轮机启动时主汽阀大开，节流压力低，减缓了在启动第一阶段汽轮机缸体温度冲击。
6.6.2 Reheater outlet steam attempertor-partial startup system 6.6.2再热器出口蒸汽减温器启动系统
Before steam is admitted to the turbine, the reheater is without flow.蒸汽进入汽轮机之前，再热器没有蒸汽。
The reheater metal absorbs heat from the flue gas and eventually reaches the temperature level of the flue gas.再热器从烟气吸热，最终达到烟气的温度。
When steam is first admitted to the turbine and paes through the reheater, reheat outlet steam temperature rises very rapidly to the gas temperature level, resulting in a poor match with the intermediate preure turbine metal temperatures for cold starts and starts following a weekend shutdown.当蒸汽首次进入汽轮机通过再热器时，再热器出口汽温很快升至烟温的水平，导致无法与在冷态和停机一周的机组汽轮机中压缸金属温度匹配，A reheat steam attemperation system, including a superheater bypa, provides a
33-30 method of startup reheat steam temperature control.一套再热器减温系统包括过热器旁路，提供启动中再热器汽温控制。
Steam attemperation, using saturated steam at the reheater outlet, limits the rise of reheat steam temperature when steam is first admitted to the turbine and offers positive reheat steam temperature control up to about 10% of full load.当蒸汽首次进入汽轮机，再热器温度陡升，减温器在再热器出口用饱和蒸汽限制再热器出口汽温，10%满负荷温度控制。
This system extends the hot start advantages described for the superheater bypa to cold starts and starts following a weekend shutdown.该系统对过热器旁路热启动、冷启动、停机一周启动都是有利的。
6.6.3 Superheater outlet steam attemperator with secondary superheater stop valve and stop valve bypa-full startup system 6.6.3 过热器出口减温器带二级过热器截止阀和截止阀旁路启动系统
For cold starts and starts following weekend shutdowns, the requirements early in the startup of low steam temperature for a good temperature match and high heat input for a quick startup are generally not compatible.With low steam flows up to about 10% to 15% of 冷启动、停机一周启动时，低汽温与好的温度匹配、高热量输入与快速启动一般是不一致的。只有满负荷蒸汽流量的10% 到15%，教材 129页
full load, the main steam temperature approaches the gas temperature in the final tube paes of the secondary superheater.第二级过热器管汽温达到烟温。
To keep the steam temperature low, the flue gas temperature must be kept low.为了降汽温，烟温也须降。
Low furnace flue gas temperature is incompatible with a firing rate and heat input high enough to generate sufficient steam from rolling and initial loading of the turbine.低的炉膛烟温与燃烧速率是不协调的，热量输入已足够产生蒸汽冲转和带最低的汽轮机负荷。
Separate systems for main and reheat steam temperature control facilitate steam-to-turbine metal temperature matching during cold startups.分离系统对主汽和再热汽温的控制有利于冷启动的汽温-金属温匹配，A partial startup system consists of reheat steam attemperation with drum steam.A
33-31 full startup system adds attemperation of superheater steam with drum steam and superheater division valves or stop valves to the partial system.部分启动系统由再热器减温器和汽包蒸汽组成。全面启动系统增加了过热器减温器、过热器分段阀或截止阀。
The superheater outlet steam attemperator, using saturated steam from the drum, permit start steam temperature control independent of heat input to the boiler.使用汽包饱和蒸汽的过热器出口减温器允许启动汽温控制，而不依赖于锅炉的热负荷。
To bypa saturated from the drum to the superheater outlet, it is neceary to install stop valves and a stop valve bypa between the primary and secondary superheater to provide flow resistance and control flow through the superheater.将汽包饱和蒸汽通过旁路引到过热器出口，一级和二级过热器之间必需安装截止阀和截止阀旁路，以避免流动阻力，并通过过热器控制流量。
Without the stop valve, the superheater preure drop during startup is insufficient to induce adequate drum steam for superheat temperature control.没有截止阀，在启动中过热器压力降是不够的，为过热器温度控制而需的蒸汽流量不够。
The secondary superheater stop valve bypa is a smaller control valve that provides preure and flow control through the secondary superheater to the turbine under low-flow startup conditions.二级过热器截止阀旁路是一个稍小的控制阀，在低流量启动时它提供从二级过热器到汽轮机的压力和流量。
The superheater outlet steam attemperator valve is used at loads le than 10% to introduce saturated steam from the drum to the superheater outlet for rolling the turbine.过热器出口蒸汽减温减压阀是用在负荷低于10%时，从汽包引饱和蒸汽到过热器出口来冲转汽轮机，Initial rolling of the turbine may be started with saturated steam through the superheater outlet steam attemperator valve, mixed with a limited quantity of steam through the stop valve bypa, and through the secondary superheater to control the high-preure turbine inlet temperature.最初的冲转蒸汽是从过热器出口减温减压阀来的饱和蒸汽加上一定量的从主汽阀旁路来的过热蒸汽，从二级过热器控制汽轮机高压缸入口温度。
On hot restarts with very high turbine metal temperature, steam temperature is controlled by furnace exit flue gas temperature with the superheater outlet steam attemperator valve closed.在热启动中汽轮机金属温度很高，过热器出口减温减压阀关闭，蒸汽温度由炉膛烟道温度控制。
33-32 For moderately high metal temperature, the attemperator valve may be used for steam temperature control to achieve a close match between entering steam temperature and first stage shell and shaft temperatures.对于中等的金属高温，减温减压阀控制汽温来获得高压缸缸温轴温与冲转汽温的匹配。
The following advantages are gained for cold starts and for stars following a weekend shutdown:对冷启动和停机一周启动的情况也会带来以下好处：
Variable preure operation during startup by throttling through the stop valve bypa with the turbine valves at or near the wide open position.在启动中不同压力运行，通过主汽阀旁路节流，而汽轮机主汽阀全开。
Optimum control of main steam temperature during startup for turbine metal temperature matching, and在启动中对汽轮机金属温度匹配是最适宜的主汽温度控制。 Reduced startup time because of the improvement in steam temperature control.因为改进蒸汽温度控制，缩短了启动时
教材 130页 第六章内容结束
33-33
