基于多模型切换控制的煤气化工业过程先进控制  

Advanced process control of coal gasification industrial process based on multiple models switching control

作　　者：张天辰 赵众[1] ZHANG Tianchen;ZHAO Zhong(College of Information Science and Technology,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]北京化工大学信息科学与技术学院,北京100029

出　　处：《煤炭学报》2023年第4期1747-1758,共12页Journal of China Coal Society

基　　金：北京市自然科学基金资助项目(4172044)。

摘　　要：煤气化是煤化工生产过程的重要组成工艺。煤气化过程以煤和氧气作为主要反应原料,在高温高压条件下发生化学反应生成粗合成气。相较石油化工行业,煤气化工业过程的先进控制(APC)实施有较大难度,原因在于煤气化过程中煤质不断变化,导致传统的基于单一模型的先进控制方法会引起控制器模型失配问题,引发生产过程中关键参数(氧煤比、气化炉温度)的较大波动。针对上述问题,基于水煤浆气化炉的生产实际,提出了一种基于多模型切换的动态矩阵控制方法。在离线状态下,利用不同煤质工况下的过程数据,构造多工况模型集。在线控制时,采取累积平方误差-总平方波动(ISE-TSV)作为控制器性能指标表征控制器性能与模型失配程度,同时使用多模型预测值作为模型切换准则。通过多模型切换动态矩阵控制,实现了煤气化单元的先进控制。根据所提方法开发了多模型切换控制软件Wisdom-Controller,在UniSim平台上进行了控制模拟,并进行了工业应用测试,模拟及工业应用测试结果证实了所提方法能够在煤质工况波动的情况下,实现氧煤比及气化炉温度的精准控制。对比传统的人工手动操作,基于多模型切换控制的先进控制方法降低了氧煤比及气化炉温度均方控制偏差。同时减少了比煤耗,增加了合成气体产量,显著提高了装置的经济效益。从而为实现煤气化工业过程的先进控制提供了一条新的有效途径。Coal gasification is a crucial unit of coal chemical production process.Coal and oxygen are used as the main reaction raw materials in the coal gasification process and the crude syngas is generated by chemical reaction under high temperature and high pressure.Compared with the petrochemical industry,it is more difficult to implement advanced process control(APC)in the coal gasification industrial process because of the time varying disturbance of coal quality.The time varying disturbance may lead to the mismatch of the APC model that could cause some large fluctuations of key process indices(oxygen coal ratio and gasifier temperature).In view of above problems,based on the actual production of coal-water slurry gasifier,a dynamic matrix control method based on multiple models switching is proposed in this paper.The off-line process data under different coal quality conditions are used to construct a multiple working model set for on-line dynamic matrix controller.The intergral squared error-total squared variation(ISE-TSV)is used as the controller performance index to monitor the controller performance and model mismatch and the multiple model prediction value is used as the model switching criterion.The advanced control of the coal gasification unit is realized through the multiple models switching dynamic matrix control.According to the proposed method,a multiple model switching control soft-ware Wisdom-Controller has been developed.The Wisdom-Controller has been tested on the UniSim simulation platform and applied to the real industrial gasifier.The simulation and industrial application results have verified that the proposed method can accurately control the change of oxygen-coal ratio and gasifier temperature under the condition of fluctuating coal quality conditions.Compared with the traditional manual operation,the mean square control deviation of oxygen-coal ratio and the gasifier temperature have been reduced obviously with the proposed advanced process control method based on multiple models switching.

关 键 词：煤气化 工况变化 多模型切换 动态矩阵控制 先进控制 

分 类 号：TQ546[化学工程—煤化学工程]