外文翻译----燃气锅炉控制系统.docx

附录2燃气锅炉控制系统锅炉燃烧系统是使燃料燃烧所产生的热量， 适应蒸汽负荷的需要， 同时还要保证经济燃烧和锅炉安全运行。首先， 要维持蒸汽母管的蒸汽压力不变， 采用双交叉限幅控制， 使锅炉系统无论在负荷上升或下降时都能满足“负荷增加时，先增加空气量， 后增加燃料量； 负荷减少时，先减少燃料量， 后减少空气量”， 以使锅炉燃烧持续保持在无黑烟状态； 其次， 保持锅炉燃烧的经济性， 以达到最小的热量损失和最大的燃烧效率； 最后， 始终维持炉膛负压在一定范围内，以使燃烧工况、锅炉房工作条件、锅炉的维护及安全运行都最有利。在工业锅炉燃烧过程中， 用常规仪表进行控制， 存在滞后、间歇调节、烟气中氧含量超过给定值、低负荷和烟气温度过低等问题。采用PLC 对锅炉进行控制时， 由于它的运算速度快、精度高、准确可靠， 可适应复杂的、难于处理的控制系统。因而，可以解决以上由常规仪表控制难以解决的问题。负荷调节是以蒸汽压力为主调参数， 蒸汽流量为前馈信号， 并考虑鼓风量的影响而进行的复杂PID 串级调节； 氧量调节通过氧量信号、蒸汽流量及鼓风量来调节炉排电机转速， 控制给煤量； 炉膛压力调节以炉膛压力为主调参数， 鼓风量为前馈信号进行P I 调节， 控制引风机转速; 在锅炉燃烧控制中，对蒸汽压力极高进行越限报警及联锁控制： 即当蒸汽压力高于报警上限时， 产生上限越限声光报警， 当蒸汽压力高于报警上上限时， 除进行越限声光报警外，PLC 发出联锁控制信号， 强制鼓风电机、引风电机及炉排电机停机， 锅炉紧急停炉， 以保证安全生产。系统硬件组成根据工艺特点及锅炉的位置分布， 选择IPC 和PLC 组成基于IPC- PLC 的三级DCS 监控系统， 整个控制系统的组成图。用三台西门子S7- 300 系列PLC 分别控制三台锅炉， 安装在中控室。PLC 用西门子的Step7 软件进行硬件组态, 所有的PID 控制、联锁保护、开关量控制均在PLC 上实现。三台PLC 通过以太网与上位工控机相连, 将现场采集的数据传给上位工控机, 并接收上位工控机的各种数据和控制命令。最上层设四台工控机, 也全部安装在中控室。其中三台作为并行运行的操作员站, 另一台作为工程师站。上位工控机采用西门子的WinCC 软件进行人机界面的编制, 并通过人机界面对下位机的所有参数进行远程设置和调整, 监控所有设备的运行情况。用WinCC 全局脚本实现模糊控制算法、锅炉效率在线实时计算和风煤比自寻优算法等。另选用一个分布式I/O 模块ET200M作为DP 从站, 通PROFIBUS- DP 现场总线与PLC 相连, 用来控制三台锅炉共用的附属设备, 如: 水处理设备、补水设备等, 实现恒压补水控制等。另外为了节能, 所有的风机、水泵和电机均采用变频控制, 变频器选用富士通用变频器。系统软件设计由于系统实现功能较多,可靠性要求高,所以软件设计的难度和工作量也变得非常之大。本系统软件采用模块化方法设计,整个任务分成若干个子任务,每个模块及其功能如下:(1) 初始化模块。对所有使用的中间继电器M、定时器T 和数据寄存器D 进行初始化处理。对一些需要初值的参量赋值。(2) TD200 人机界面模块。该模块主要处理人机界面的智能显示逻辑和对TD200 组态信息的使用。(3) 增管、减管判断模块。判断何时增减电热管及相关逻辑。(4) 电热管投入和退出逻辑模块。根据增减电热管的判断结果和目前电热管的运行状态,来决定哪一组电热管应该投入或退出。该逻辑在各子程序中完成。(5) 电热管各种工作模式模块。根据工作模式的选择,系统可分别进入常规模式、经济模式及半经济模式工作。要做到正确的工作模式选择,加热管工作个数的确定非常重要,S7 - 200 PLC 中没有SUM 指令,所以要建立一个存储单元,每组电热管通电和退出时,分别对该存储单元进行加1 和减1 运算,这样存储单元中的值就是加热管工作的个数。(6) 输出处理模块。(7) 报警处理模块。处理各种报警信息。1 汽包水位调节在负荷比较稳定的情况下, 汽包水位一般采用典型的三冲量水位调节即可获得较为理想的控制效果。但是, 在负荷变化较大的情况下,采用上述典型控制算法效果不理想, 水位和蒸汽压力经常出现报警, 根本无法使系统稳定工作, 甚至无法实现自动控制。锅炉负荷就属于这种情况。因此, 我们在典型的三冲量控制中增加了一些补偿算法, 并对测量参数进行了适当处理, 现场实际投运后效果很好。由于水位稳定, 使得蒸汽压力自动控制成为可能,从而解决了因蒸汽压力过低进口设备无法正常运行的难题。另外, 在软件中对操作量输出进行了补(运算, 即增加了输出限幅, 但该限幅是在线自整定的, 即克服了给水阀动作频繁, 阀体容易磨损的问题, 延长了电动调节阀的使用寿命, 又解决了由于输出限幅造成的在蒸汽流量突然增大时, 水位调节速度慢的问题。2 炉膛负压调节炉膛负压调节采用前馈回路以克服送风量变化造成的干扰, 用反馈回路克服偏差, 控制引风机的转速, 达到改变风量的大小, 使炉膛负压维持在给定范围内。在引风输出中也增加了输出限幅以减少引风机频繁动作。同样, 由于负荷变化较大, 也增加了限幅在线自整定算法。3 蒸汽压力及风煤配比调节这是一个多回路前馈调节系统, 蒸汽压力PID 调节的输出加上修正算法作为风量调节的给定, 而风量PID 调节的输出控制鼓风机的变频调速, 同时又通过比值调节控制炉排电机的变频调速, 从而改变送风量和送煤量。为减少在蒸汽负荷变化时对蒸汽压力的扰动, 引进了蒸汽流量作前馈调节。在这个调节回路中, 不但增加了炉排输出限幅的在线自整定, 而且当蒸汽流量突然变化时, 还增加了风煤配比的在线自整定, 用来既保证在蒸汽流量突然增大时仍能保证蒸汽压力大于7kg, 又能保证在蒸汽流量突然减少时蒸汽压力不会超限, 使系统保持稳定, 同时还达到了既节能又不冒黑烟的效果。出水温度控制系统主要实现根据室内外温度测量值和室外风速, 调节给煤量、鼓风量和引风量, 从而实现按需供热、安全经济环保运行的目的。出水温设定值随室外环境温度的变化自动调整。给煤量根据出水温度测量值与给定值之间的偏差, 采用模糊控制算法进行调整, 以达到快速调整出水温度的目的。同时, 根据锅炉效率实时在线计算的结果, 对给煤量进行微调, 从而保证锅炉的经济燃烧。鼓风量根据给煤量和风煤比的变化, 采用常规PID 算法进行调整, 实现比值控制, 达到完全燃烧、经济燃烧的目的。其中根据能量平衡理论, 采用自寻优算法对风煤比进行在线实时调整, 使燃料与空气始终保持最佳的配比, 实现燃料的完全燃烧。引风量根据炉膛负压测量值, 采用常规PID 算法进行调整, 并将鼓风量作为前馈量, 实现前馈反馈控制, 以保持炉膛的微负压状态, 确保锅炉安全运行。参考文献：计算机应用. 2002.07附录3Boiler Control SystemBoiler combustion system is produced by fuel combustion heat to adapt to the needs of steam load, we need to ensure that the economic boiler combustion and safe operation. First, the mother of steam to maintain the steam pressure remains unchanged, a dual-limiting control, the boiler system in load increased or decreased at will meet the load increased, to increase the volume of air, after the increase in fuel; reduce the load , To reduce the amount of fuel, reducing air after , so that the boiler combustion in the absence of black smoke continued to maintain state and secondly, to maintain the economic boiler combustion, so as to minimize heat loss and the largest combustion efficiency; Finally, always maintain Furnace negative pressure in a certain range, so that the burning conditions, working conditions boiler room, boiler maintenance and safe operation are the most favourable. In the industrial boiler combustion process, the use of conventional instrumentation control, there stagnant, intermittent conditioning, oxygen content in the flue gas over a given value, low load and low temperature gas, and other issues. PLC used to control the boiler, because of its high speed, high precision, accurate and reliable, can adapt to complex and difficult to deal with the control system. As a result, more than can be solved by conventional instrumentation control difficult issues. . Load regulation is the main tune parameters of steam pressure, steam flow for the feed-forward signal, and to consider the impact of the blast in the complex cascade PID regulation; oxygen through the oxygen signal conditioning, and the blast of steam flow to regulate Grate Motor speed, control the volume of coal, furnace pressure adjusted to the pressure chamber for the main parameters of the blast before the Fed signals PI regulation, with fan speed control in the boiler combustion control, the high pressure steam to the limit and alarm Interlocking control: that is, when the steam pressure higher than the warning limit, a ceiling of the limited sound and light alarm, when the steam pressure higher than the alarm on the limit, in addition to the restrictions of sound and light alarm, PLC issued interlock control signals, forced the dark Feng Motors, with winds of Electrical and grate the electrical shutdown, emergency boiler Boilers off Load, to ensure production safety. System hardware According to characteristics of the boiler and distribution, select PLC IPC and IPC-PLC-based components of the three DCS control system, the composition of the entire control system plans. With three Siemens S7-300 series PLC control were three boilers, installed in the control room. PLC with Siemens Step7 software to the hardware configuration, all of the PID control, interlocking protection, volume control switch in the PLC are to achieve. PLC via Ethernet and three top industrial computer connected to the data collected at the top IPC transmission and reception of the top industrial computer data and control commands. The top four for IPC, also installed in the control room. Three of them as a parallel operation of the operator station, another station as an engineer. Upper IPC use the Siemens WinCC human-computer interface software for the establishment, and through human-computer interface for the next crew of all the parameters for remote settings and adjustments, monitor the operation of all equipment. WinCC script with the overall realization of fuzzy control algorithms, boiler efficiency of coal-line real-time calculation and wind than self-optimizing algorithm. Another choice of a distributed I / O modules ET200M from the station as the DP, through PROFIBUS-DP fieldbus connected with the PLC, the three boilers used to control the sharing of ancillary equipment, such as: water treatment equipment, water supplement equipment, and constant Water pressure control. In addition to energy conservation, all the fans, pumps and motors are used Frequency Control, Drives Fujitsu General optional converter. System Software Design As more functional systems, high reliability requirements, software Design and the difficulty of the workload has become very large. The mining system software Modular design approach used, the whole mission is divided into several sub-tasks, each Module and its functions are as follows: (1) to initialize module. The use of all the intermediate relay M, set When T-D registers and data processing to initialize. The need for some To the initial parameter assignment. (2) TD200 human-computer interface module. The module is primarily concerned with human-computer Intelligence shows that the interface logic and configuration information on the use of TD200. (3) by tube, by judgement of the module. Determine when changes in the electric and Related logic. (4) electric input and exit of logic modules. According to increase or decrease in electric And the results of the judgement of the electric current running state, to decide which Electric Group should join or withdraw from the tube. The logic in all routines in the End 10%. (5) of various electric mode module. According to the mode of work Choice, the system can be entered conventional model, economic model and semi-economic model Working. To achieve the correct mode of choice, a heating pipe work Determine the number of very important, S7 - 200 PLC did not SUM command, Therefore, to build a storage unit, each of electric power in and out, The storage unit were carried out by a Canadian and an operator, this single store Yuan in value is the number of heating pipe work. (6) export processing module. (7) alarm processing module. Dealing with all kinds of warning messages. 1 drum level adjustment Load in the relatively stable situation, the general drum water level typical of the three-volume water level regulation can be better control. However, the larger changes in the load cases, the typical control algorithms are not effective, water and steam pressure often the police simply can not make the system stability, or even impossible to achieve control. Boiler load on the case. Therefore, we in a typical three-volume control has been added to some compensation algorithm, and measurement parameters are properly addressed and put into operation at the scene after the actual good effect. As the water level stability, makes it possible to control steam pressure, so as to solve the steam pressure is too low for imported equipment can not be normal operation of the problems. In addition, the software exports in the operation of a meeting (computing, representing an increase of the output limiting, but it is limiting on-line self-tuning, that is to overcome the frequent moves to the valves, valve body to wear the issue of extension of the Electric control valve life, to solve the limiting output due to the sudden increase in the flow of steam, the water level of slow adjustment problems. 2 vacuum furnace regulation Vacuum Furnace regulating use of feed-forward loop to overcome the air supply of changes in the disruption caused by feedback loop to overcome bias, with fan speed control, to change the size of the wind, so that the furnace to maintain negative pressure in a given area. With the wind in output also increased by limiting output to reduce Fan frequent moves. Similarly, the larger load changes, also increased by limiting on-line self-tuning algorithm. 3 steam pressure and oxy-acetylene ratio adjustment This is a multi-loop feedforward-conditioning systems, steam pressure PID regulator added that the output of wind as a method of adjusting a given, but the wind of P ID-conditioning control the output of the blower Frequency Control, but also by adjusting the ratio of motor control Grate The Frequency Control, in order to change the air supply and delivery of coal. To reduce the load of steam when the steam pressure in the disturbance, the introduction of steam flow for feed-forward regulation. In this regulation circuit, will not only increase the output limiting Grate the online self-tuning, and when the steam flow suddenly changes, also increased the oxy-acetylene ratio of online self-tuning, both to ensure that a sudden increase in the flow of steam Can guarantee that when the steam pressure is greater than 7 kg, can guarantee that a sudden reduction in the flow of steam when the steam pressure will not be overrun, allowing the system to maintain stability, also reached both energy conservation without the effect of black smoke.Water leakage temperature control system: mainly realizes acts according to the indoor outside temperature observed value and the outdoor wind speed, adjusts for the coal amount, the drum amount of wind and directs the amount of wind, thus realizes on demand to heat, the security economical environmental protection movement goal. Leaves the water temperature setting value along with the outdoor ambient temperature chang