电站锅炉燃烧系统优化策略的研究

发布时间：2018-04-15 16:39

本文选题：电站锅炉燃烧系统 + DCS　；参考：《辽宁科技大学》2014年硕士论文

【摘要】：电站锅炉是电站生产中的主要设备之一，提高锅炉的控制效率对整个企业在经济效益、安全生产、环境保护等方面起着关键作用。本文以锅炉燃烧系统为研究对象，其本身是一个多输入、多输出，耦合性强，滞后比较大的系统，在对燃烧系统的主要参数以及采用常规控制时效果不理想进行分析的基础上，提出采用先进控制方法对控制系统做出改进，最终达到改善锅炉控制的目的。锅炉燃烧系统是锅炉三大系统中重要的一个，它关系着蒸汽的品质、锅炉燃烧的经济性以及运行的安全性。在锅炉常规PID控制中，往往因为内部或者外部因素的强烈干扰，使得锅炉燃烧控制得不到良好的控制效果。因此，随着现代控制理论的发展和成熟，人们将一些先进的控制理念，例如神经网络控制、模糊控制、专家控制和预测控制等，相互结合或者同常规PID控制进行结合，组成更为有效的控制方式，在实际应用中都得到了良好的控制效果。集散控制系统（DCS）是当今自动化高速发展的重要标志，随着电力行业进入大型化、高度自动化时代，DCS的应用已经成为必然趋势，它的运用给电力行业或者其它工业企业都带来了巨大的利益，不仅满足了经济上的需要，同时满足了环境对工业生产的要求。本文针对锅炉燃烧系统的特点，，同时为了方便的对系统进行分析进而采用更有效的控制方法，故将锅炉燃烧系统分为相互独立的三个子系统：蒸汽压力控制系统（燃料量控制系统）、烟气氧含量控制系统（送风控制系统）、炉膛压力控制系统（引风控制系统）。在对三个系统的结构和机理进行研究分析的基础上，以及对PID控制、模糊控制、预测控制充分的研究上，将算法同DCS系统相结合，把燃烧优化得到的控制量送到DCS中，由其对现场设备进行控制，达到锅炉燃烧优化的目的。具体的优化方案是：1）充分利用预测控制和模糊控制各自的优势，采用模糊控制与预测控制结合的方法对锅炉蒸汽压力进行控制，调节蒸汽品质；2）采用模糊和PID相结合的控制方法对炉膛压力和烟气氧含量进行控制，提高锅炉运行的经济性和安全性。最后运用MATLAB进行仿真实验，结果表明采用模糊预测控制和模糊PID控制有效的减小了系统稳态误差，系统响应时间、超调量等重要参数指标都得到了改善，具有一定的实用价值。
[Abstract]:Boiler is one of the main equipments in power plant, improve the control efficiency of the boiler to the enterprise production safety in the economic benefit, and plays a key role in environmental protection. Based on the boiler combustion system as the research object, which itself is a multi input, multi output, strong coupling, large time delay system the main parameters of the combustion system, and the basis of conventional control effect is not ideal on the analysis, put forward using advanced control methods to make improvements to the control system, to improve the boiler control.
Three boiler boiler combustion system is an important system, it is related with the quality of the steam boiler combustion, economy and safety of operation in the boiler. The conventional PID control, often because of the strong interference of internal and external factors, the boiler combustion control can not get good control effect. Therefore, with the the development of modern control theory and mature people, some advanced control concepts, such as neural network control, fuzzy control, expert control and predictive control, combined with each other or with the conventional PID control combined with the more effective control way, has good control effect in practical application.
Distributed control system (DCS) is an important symbol of the rapid development of automation, along with the development of electric power industry into large-scale, highly automated era, the application of DCS has become an inevitable trend, it is applied to the electric power industry or other industrial enterprises have brought huge benefits, not only to meet the needs of the economy, at the same time to meet the requirements of environment for the industrial production.
According to the characteristics of the boiler combustion system, at the same time in order to facilitate the analysis of the system and the control method is more effective, the boiler combustion system is divided into three subsystems: independent steam pressure control system (fuel control system), control system of oxygen content in flue gas (air control system, furnace pressure control) system (wind control system). The researches on the structure and mechanism of the three systems, as well as the PID control, fuzzy control, predictive control research on full algorithm with DCS system combined with the optimal combustion control amount is sent to the DCS, by the control of site equipment, achieve the boiler combustion optimization. Specific optimization scheme is: 1) predictive control and fuzzy control to make full use of their respective advantages, using fuzzy control and predictive control method based on pressure steam boiler The force is controlled and the steam quality is adjusted. 2) fuzzy control combined with PID is applied to control the furnace pressure and the oxygen content of the flue gas, so as to improve the economy and safety of the boiler operation.
Finally, MATLAB is used to carry out simulation experiments. The results show that fuzzy predictive control and fuzzy PID control effectively reduce the steady-state error of the system, and the important parameters such as system response time and overshoot are improved, which is of practical value.

【学位授予单位】：辽宁科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621.2

【参考文献】