火电厂超临界机组燃烧控制系统的建模与控制

发布时间：2018-05-18 13:28

本文选题：超临界机组 + 燃烧控制系统　；参考：《华北电力大学》2014年硕士论文

【摘要】：火电厂超临界机组燃烧控制系统主要是将燃煤所产生的热能转换为蒸汽动能的能量转换系统,是整个火电厂系统的能源动力来源,深入了解燃烧控制系统以便能够从源头上提高火电厂超临界机组的整体运行效率。本文以火电厂超临界机组燃烧控制系统为研究对象,相关的研究工作主要集中在对象建模和控制算法这两个方面。一个完整而精确数学模型是机组燃烧控制系统的设计和控制的基础,控制理论的广泛应用不能脱离被控系统的数学模型,正确的模型能够反映各个热工自动化设备的参数及其动态响应过程,从而帮助工程人员充分了解机组的运行动态特性。本文对火电厂超临界机组燃烧控制系统进行了详细的机理分析,以微分方程组的形式分别给出了燃烧控制系统四个子系统：磨煤机子系统、主蒸汽压力被控量子系统、烟气含氧量被控量子系统和炉膛压力被控量子系统的数学模型,再根据输入量输出量的关系,以及燃烧控制系统内工质的流动和传热过程,将各子系统串联,从而建立了火电厂超临界机组燃烧控制系统的整体机理模型。之后为验证建立模型的正确性,研究了在100%负荷,75%负荷,50%负荷和35%负荷的工况下,给煤量、送风量和引风量三个输入变量分别单独做阶跃扰动时系统模型三个输出变量主蒸汽压力、烟气含氧量和炉膛压力的动态响应曲线特性。针对燃烧控制系统是一个存在着强耦合、强干扰、非线性和大时延等特性的复杂系统,及实际运行时还受一些外部未知因素的干扰特点,本文采用了模糊自整定PID控制算法对其进行了控制,模糊自整定PID控制算法可以根据系统的控制状态,智能的调整控制器的参数,以达到稳定、快速的控制效果。仿真结果表明,相比于传统控制方法模糊自整定PID控制在火电厂超临界机组燃烧控制系统上具有更优的控制品质。
[Abstract]:The combustion control system of supercritical unit in thermal power plant is an energy conversion system that converts the thermal energy generated by coal combustion into steam kinetic energy and is the energy power source of the whole thermal power plant system. In order to improve the overall operation efficiency of supercritical units in thermal power plants, the combustion control system can be deeply understood. In this paper, the combustion control system of supercritical unit in thermal power plant is taken as the research object, and the related research work is mainly focused on two aspects: object modeling and control algorithm. A complete and accurate mathematical model is the basis of the design and control of the unit combustion control system. The extensive application of the control theory cannot be separated from the mathematical model of the controlled system. The correct model can reflect the parameters and the dynamic response process of each thermal automation equipment, so that the engineers can fully understand the dynamic characteristics of the unit. In this paper, the mechanism of combustion control system of supercritical unit in thermal power plant is analyzed in detail. Four subsystems of combustion control system are given in the form of differential equations: coal mill subsystem, main steam pressure controlled quantum system. The mathematical models of the controlled quantum system of flue gas oxygen content and the controlled quantum system of furnace pressure, and then according to the relation of the input and output quantity, and the flow and heat transfer process of the working fluid in the combustion control system, the subsystems are connected in series. The integral mechanism model of combustion control system of supercritical unit in thermal power plant is established. Then, in order to verify the correctness of the model, under the conditions of 100% load of 75% load of 50% and 35% of load, the quantity of coal supply is studied. The dynamic response curves of the main steam pressure, flue gas oxygen content and furnace pressure of the three output variables of the system model were obtained when the three input variables of the air supply and the inlet air were separately made step disturbance. The combustion control system is a complex system with strong coupling, strong interference, nonlinear and long time delay, and is also disturbed by some external unknown factors in actual operation. In this paper, the fuzzy self-tuning PID control algorithm is used to control it. The fuzzy self-tuning PID control algorithm can adjust the parameters of the controller intelligently according to the control state of the system, in order to achieve stable and fast control effect. The simulation results show that the fuzzy self-tuning PID control has better control quality than the traditional control method in the combustion control system of supercritical units in thermal power plants.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621

【参考文献】