煤气混合过程的智能解耦控制算法及其应用研究

【作者】 何成燕；

【导师】 曹卫华； 吴敏；

【作者基本信息】 中南大学 ， 控制理论与控制工程， 2007， 硕士

【摘要】 在钢铁企业中，一些设备如高炉、焦炉和转炉都会生成副产品——煤气。煤气混合过程即为回收利用这些副产煤气，不仅节约能源，而且降低了环境污染，是钢铁生产的重要环节。混合煤气热值和压力稳定与否，影响到煤气质量、设备寿命、生产环境以及钢铁生产的质量和产量。因此研究煤气混合过程控制对钢铁工业生产有着重要的意义。煤气混合过程是一个高度复杂的工业过程，具有多变量强耦合、非线性、不确定性、时变、难以建立数学模型等控制难点。本文在充分分析煤气混合过程的特点和控制难点的基础上，提出一种智能集成解耦控制算法，通过融合模糊控制算法、专家控制算法、智能解耦算法先进技术进行设计，逐层实现解耦。首先，针对煤气混合过程单变量的变化特性，选择“粗调”或“精调”模糊控制器，并利用专家控制算法对特殊工况条件下的模糊控制输出作适当调整；同时采用前馈专家控制算法，对大扰动进行补偿。然后，采用模糊解耦控制算法实现煤气混合过程的多变量之间的解耦。本文在总结操作人员的经验，分析煤气混合过程特性和蝶阀属性的基础上，采用基于专家规则的模糊解耦控制算法，克服回路间的相互干扰，近似地将多变量过程分解为独立的单输入单输出过程。最后，设计了蝶阀控制器。通过分析蝶阀属性，推导蝶阀并联、串联的相对增益矩阵，给煤气热值压力解耦控制规则的设计、高阀增量与焦阀增量在两道阀门上的分配提供了理论依据；另外，根据蝶阀的流量特性曲线设计了蝶阀专家控制器，提高了控制品质。控制算法在某钢铁公司的两类煤气混合过程中得到了实际应用。运行结果表明，算法具有简便、易行、可靠、易扩充及抗干扰能力强等优点，在控制对象的数学模型难以确定的情况下，实现了焦炉、高炉混和煤气热值与压力，以及多座焦炉集气管压力的稳定，创造了显著的经济效益和社会效益，同时大大减轻了工人的劳动强度，为煤气混合过程的解耦控制提供了一种有效的途径。更多还原

【Abstract】 In the iron and steel enterprise, some equipment such as blast furnace, coke ovenand converter oven will generate byproduct gas. The gas mixing process is to recyclethis byproduct gas which not only saves energy but also reduces environmentalpollution. It is an important link in the iron and steel production. The calorific valueand pressure’s stability directly influences the gas quality, the life-time of ovens,producing environment and the iron’s quality and quantities. Therefore, research ongas mixing process control is a vital significance for the iron and steel enterprise.The gas mixing process is a very complex industrial process. The features ofmulti-variable, strongly coupled, nonlinear, changeable parameters, and hard inmodeling are the major control challenges in the gas mixing process. Based onprofound researching on the characters and control difficulties of gas mixing process,this paper proposes an intelligent integrated decoupling control algorithm, whichincorporates decoupling control with fuzzy control, feedforward control and expertcontrol.At first, through analyzing the characteristics of gas mixing process singlevariable, adopt "rough adjustment" or "fine adjustment" fuzzy controller, and useexpert control algorithm for special working conditions. At the same time,compensate big perturbation by using the feedforward expert control algorithm. Thenfuzzy decoupling control method is adopted to realize the decoupling ofmulti-variables of gas mixing process. Based on summarizing the experience ofoperating workers and analyzing the characters of gas mixing process and butterflyvalves, this paper designs fuzzy decoupling control method based on expert rules,similarly decompose the multi-variable process to single input, single output process,and hierarchically eliminate the coupling among each loop. Finally, butterfly valvecontroller is designed. Through analyzing the butterfly pai’allel and series relative gainmatrix, theoretical basis is created for the design of gas calorific value and pressuredecoupling control rules, the distribution of blast furnace valves control value andcoke oven valves control value to each two valves. Furthermore, butterfly valveexpert controller is developed to adapt to the characteristic of butterfly valve so as toenhance the control quality. The control algorithm is applied in two type gas mixing processes in some ironand steel company. The actual run result showed that, the control algorithm is simple,feasible, reliable, and easy to expand and strongly resisting, even when the controlledmember mathematical model is difficulty to determined, realized the stability of thecoke oven and blast furnace mixing gas calorific value and pressure, of the pressure ofmulti coke oven gas collectors. It has created great economic and social benefits;meanwhile, it also lessens the labor intensity. In a word, it provides an efficientmethod for the decoupling control in the gas mixing burning process.更多还原