【作者】 王泽；

【导师】 郑晟；

【作者基本信息】 太原理工大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 供热锅炉的燃烧控制对于供热系统的供热调节和锅炉的安全、高效运行和节能降耗都具有重要意义。锅炉燃烧系统是一个复杂的时变动态过程,具有很强的非线性、紧耦合、大时滞、强干扰等特性,传统的控制算法很难得到理想的控制效果和较高的投运率。所以如何应用当前的一些先进的控制策略对锅炉燃烧进行有效控制,保证锅炉供热输出与热网负荷变动相适应的供热量,并保证锅炉安全、经济、稳定运行是当前研究的热点课题。本文在分析锅炉燃烧系统动态特性的基础上,深入研究了锅炉燃烧系统中各个参数之间的关系,将供热锅炉燃烧控制简化为对锅炉给煤量、二次风送风量以及引风量的控制。在锅炉燃烧系统的控制实现上,本论文结合广义预测控制和模糊控制的特点提出了:对锅炉给煤量实行由广义预测控制和PID控制组成的串级控制;对二次送风量提出以炉膛温度(具体实现实时采用烟道温度)为控制目标,实行对风煤比进行自寻优的模糊控制;另外对引风量的控制本文提出在大偏差范围内实行模糊控制,小偏差范围内实行PI控制的控制策略。本课题源于煤炭科学研究总院在山西大同市煤粉锅炉改造推广工程,课题研究内容主要是为其设计配套的锅炉供热燃烧自动控制系统。在项目期间,系统地研究了锅炉燃烧控制的一些重要特性,对文中提出的控制策略结合现场实际情况做了大量深入的分析调试。尤其是在二次风机的风煤比自寻优控制上,本文结合火焰监测仪提供的火焰强度值改善了原来二次风机变频控制对炉膛负压影响较大的缺点。改进后的模糊自寻优控制以火焰强度值为启停条件,并根据螺旋给料机实时变频值对自寻优控制输出采取一定范围的限幅。通过控制室内火焰监视器,可以明显看到采用这种控制策略后,锅炉燃烧火焰变得明亮稳定。项目中采用施耐德QUANTUM系列PLC对煤粉锅炉供暖系统实现了自动送煤、燃烧、煤粉仓温度控制、循环水控制、补水控制、除尘、锅炉点火的全程控制。更多还原

【Abstract】 Boiler combustion control is of great significance for heating system in heating regulation, boiler’s safety, energy saving and high efficient operation. Boiler combustion system is a complex time-varying dynamic process, which has highly nonlinear, tightly coupled, long delay and strong interference characteristics. The traditional control algorithms are difficult to obtain the ideal control effects and higher operation rates. Therefore, it is a hot topic on the current research that how to use some recent advanced strategies for effective control to the boiler combustion ensures the heating supplies of boiler’s heating output and heat-network’s changing loads and ensures boiler’s safety, economy and stable operation.Based on the analysis of dynamic characteristics of boiler combustion system, the paper deeply studies the parameters relationship of boiler combustion system. The heating boiler combustion control is reduced to control of the coal supply of boiler, secondary air volume and importing air volume. In the realization of boiler combustion control system, the paper, combining the characteristics of generalized predictive control and fuzzy control, puts forth the cascade control system that is made up of the generalized predictive control and PID control and to make the furnace temperature as control objectives for the secondary air supply and to implement self-optimizing fuzzy control to the oxy-acetylene ratio. Besides, the thesis introduces strategies of using the fuzzy control in large deviation and employing the PI control in small deviation to the air volume controlThe subject derived from a project of China Coal Research Institute in Da Tong city of Shan Xi province, prompting the use of pulverized Coal Boiler. When furnishing auto control system for Boiler Heating system, systematically studying the traits of boiler combustion control. On the wind and coal proportion self-optimizing control of secondary wind motor, this article improves the using of self-optimizing control, which has heavy impact on the negative pressure of boiler through controlling secondary wind motor. Based on the real time frequency-converting value, improved fuzzy self-optimizing control limit its output by using the frame intensity as condition of start and stop to the original routine. From the frame monitor in the control room, it is obvious that the boiler combustion frame becomes bright and stable using this control strategy.In this project, Schneider QUANTUM PLC is used in coal powder boiler heating system to achieve the overall control of automatic coal delivery, combustion, coal warehouse temperature control, water cycle control, replenishment control, dust catch, boiler ignition.更多还原