智能控制技术在氧化铝熟料烧结回转窑中的应用

Minin g &Processin g E q ui p ment2004.0755分・选图1熟料窑智能优化专家控制系统原理框图论文编号:1001-3954(2004)07-0055-55智能控制技术在氧化铝熟料烧结回转窑中的应用温艳芬李化民卫会玲中国铝业山西分公司技术开发部山西河津043300中国铝业山西分公司是我国目前最大的氧化铝生产基地,年产氧化铝130万t 。

其氧化铝生产工艺采用拜耳、烧结混联法生产方式。

烧结法流程是为处理低品位铝矿和拜尔法赤泥设计的,熟料窑是其中的关键设备。

传统的熟料窑在生产中存在的主要问题是:操作工在窑前小车室凭视觉直接看火,凭经验调整给煤量,主观因素较多,由此导致生产不稳定、设备运转率低和产能低等问题,同时由于回转窑设备的特殊性(<4.5×110m ),窑内气体混浊,看火操作难度大,随着计算机技术和自动控制技术的快速发展,应用先进的控制技术解决复杂工业过程控制问题成为可能。

2002年中铝山西分公司在一台熟料窑进行了自动控制系统的现场实施,成功开发了熟料窑智能控制模型软件,并投入生产试运行,取得显著的应用效果。

1系统控制的关键要点熟料烧结过程中,合格的生料浆用料浆泵经安装在窑尾的喷枪呈雾状喷入熟料窑内,煤粉从窑前的喷煤管与鼓风机送来的一次风结合形成气固两相流喷入窑内,并与由冷却机吸入的“二次风”一起燃烧,产生的热量与生料浆逆向而行,生料浆经过烘干、预热、分解、烧成带被加热到1200～1300℃之间发生化学反应,生成可溶性铝酸钠和铁酸钠。

由于熟料窑体积庞大,内部烧结过程特性复杂,关键变量如窑内温度、下煤量、下料量、风量、窑速等耦合严重;运行条件与工况变化大,如窑内衬、窑皮的厚薄、生料浆流量、水分、成分、燃料煤质等变化频繁;关键工艺参数烧成带温度难于准确测量;基于数学模型或增益恒定的控制方法难以适用。

针对生产过程特点,采用智能滤波、多信息融合、模式识别等智能建模技术与智能预测控制、自适应控制、多模态控制等控制技术在工业控制计算机上开发了智能控制系统。

2智能控制系统简介智能控制系统主要由特征信息预处理部分、特征模式集、推理机构、控制算法集、人机协调接口组成,如图1所示。

(1)特征信息预处理的核心部分包括烧成带温度低通滤波模块、智能滤波模块,变时间尺度处理特征信息模块。

系统实施中利用在窑前安装非接触式测温装置测量烧成带温度,该温度测量值是控制方案依据的主要特征信息之一,为防止粉尘烟雾干扰较严重时造成控制器的误动作,对该温度检测值首先采用低通滤波方法进行滤波;回转窑由于窑圈形成或窑尾结疤都会影响回转窑的通风特性,造成火焰在窑内窜动,使该温度检测值异常,这种因随机干扰而产生的瞬时波动并不真正反映烧成带内实际温度变化,将对后续的模式识别造成干扰,因此对经低通滤波后的烧成带温度再设计智能滤波处理。

特征模式集所利用的特征信息来源于回转窑过程工艺参数的原始检测值,包含烧成带温度、窑尾温度、窑头温度、烟气O 2含量、生料浆流量等。

(2)特征模式集包括:软开关程序控制器触发特征模式类、自适应模糊控制器触发特征模式类、自适应预测控制器触发特征模式类、工况匹配风煤协调控制器触发特征模式类。

通过用这些特征状态模式直观地反映系统动态过程的工作运行状态,以作为智能控制系统推理、判断依据。

(3)控制算法集主要由自适应预测控制器、工况匹配风煤协调控制器、调度协调单元模块组成。

①自适应预测控制器利用“用煤水平目标值”特征记忆信息,遵循能量守恒原理,基于模式特征自适应调节用煤水平,克服烧成带温度被控对象具有的测量特殊性、干扰严重、大滞后、大惯性,保证窑热量传递平衡,热工制度稳定。

②工况匹配风煤协调控制器采用智能协调控制技术,从整个回转窑生产过程中互相影响的各变量整体考虑,根据被控变量烧成带温度、窑尾温度、烟气O 2含量组合的不同工况,对控制变量给煤量、二次风量进行协调控制。

③调度协调单元模块负责自适应预测控制器与风煤协调控制器之间的协调问题,按目标优先权将二者集成起来,计算最终的风煤调节量输出给执行机构。

(4)模式识别部分:起推理机构的作用,根据当前时刻的特征变量去知识库中搜索与提供的约束条件相匹配的特征模式,为控制决策提供前提条件。

本控制系统采用前向推理机制,对于特征变量和生产工况各种模式由前向后逐条匹配,满足条件则启动相应控制算法。

(5)人机协调接口:针对熟料窑生产边界条件如生料成分、煤质波动频繁的现状,自动控制系统离不开人的参与,本系统中开发了人机交互运行监督接口,允许操作人员在控制系统实时控制的基础上,根据设备状况及生产条件对智能控制系统的自动调节范围给予约束限定。

3应用效果智能控制系统投入使用后,避免了人为主观因素对窑热工制度和运行条件造成的影响,保证了熟料烧成生产的科学性、平稳性,明显延长了熟料窑内衬的使用寿命,与控制系统实施前3#窑指标相比,台时产能提高了2t/h ,运转率提高1.5%,达到了提高熟料窑运转率和节能降耗的长期效果,产生了显著的经济效益和社会效益。

□(收稿日期:2004-02-18)© 1995-2006 Tsinghua Tongfang Optical Disc Co., Ltd. All rights reserved.Se p aratorsCalculation of Filter Ratio of Multi-La y er Screen.................... ......................................YOU Sikun et al.(39-40) The p a p er int roduces t he calculatin g met hod of filterin g ration of vibration multi-la y er screen b y calculatin g in j ection area wit h in j ection mold based on software.Pro/E,which p rovides p owerf ul su pp ort for t he desi g n and selectionof multi-la y erscreen.【Descri p tors】Multi-La y erscreen Filter2 in g ration In j ection areaAnal y sis on Chaotic Vibratin g Screen Mode..WAN G Zhen g hao(40-41) The p a p er makes modal anal y sis and st ruct ural modification of chaotic vibratin g screen,and p ut s forward some noticeable p roblems on t he st ruct ural desi g n of screen box.【Descri p tors】Chaotic vibratin g screen Modal anal y sis St ruct ural modification Screen box St ruct ural desi g n Modal Anal y sis of Deck Base of Linear Vibratin g Screen Machine and St ud y on Fault Dia g nosis.....................L IU Jianwen(41-43) B y makin g vibration mode anal y sis to t he deck base of ZKX t yp e linear vibratin g screen machine,t he weak st ruct ure of machine is found out, which p rovided t he t heoretical basis for scheme desi g n of technical im2 p rovement of screenin g machine.【Descri p tors】Linear vibratin g screen machine Vibration mode anal y sis Fault dia g nosisResearch on Techni q ue of Ra p id Heat Rreat ment for Steel Wire t hat Is Used to Make Vibratin g Screen of Mine Screenin g Machine............ ...................................WAN G Dian j un et al.(44-45) The p a p er g ives an int roduction to t he p rinci p le of direct elect ricit y t ransmission and ra p id heatin g for steel wire used to make vibratin g screen,p ro p erties and characteristic of steel wire,and main factors which affect it s p ro p erties.It also g ives t he determined met hod b y which obtain t he necessar y current,volta g e and p ower for direct elect ricit y t ransmis2 sion and ra p id heatin g to t his steel wire【Descri p tors】Vibratin g screen Ra p id heatin g St ren g t hRemovin g t he Resonance Vibration t hat Arise f rom Two-Axle Linear Vi2 bratin g Screen b y Counter-Tor q ue Brakin g Met hod.....CHEN Yu(50-51) The p a p er anal y ses t he inevitabilit y of resonance vibration t hat arise dur2 in g o p eratin g on t he basis of t he o p eratin g p rinci p le of two-axle linear vibratin g screen and vibration characteristic curve.It also su gg est s ado p tin g countertor q ue brakin g met hod to remove resonance vibration, which p roves to be effective b y p ractice.【Descri p tors】Vibratin g screen Counter-Tor q ue brakin g Resonance RnmoveAnal y sis on t he Workin g Princi p le of Torsional Vibrator and It s O p ti2 mization.............................ZHAN G Hon g bin g(51-53) The p a p er makes t heoretic anal y sis on t he kinetic p rinci p le of torsional vibrator f rom t he p oint of view of kinetics,o p timizes t he desi g n p arameter of vibrator,and p ut s forward t he reasonable desi g n scheme accordin g to t he excitin g p rinci p le and it s movement characteristic.【Descri p tors】Torsional vibration Vibrator Kinetic anal y sis O p timizin g desi g nUlt ra-Gravit y Techni q ue and It s A pp lication in Dust Process......... .....................................CAO Xuemin et al.(53-54) Ult ra-g ravit y techni q ue is u kind of newborn one which em p hasizes t he conve y ance course.The p a p er g ives an int roduction to t he p rinci p le of t he techni q ue and it s a pp lication in dust p rocess.【Descri p tors】Ult ra-Grav2 it y techni q ue Dust p rocess Rotar y p acked bedA pp lication of Intelli g ent Cont rol Techni q ue in Processed Alumina Sin2 terin g Rotar y Kiln....................WEN Yanfan g et al.(55-55) The p a p er states t he p roblems t hat exist s in t he p rocessed alumina sin2 terin g p rocess,and g ives a detailed int roduction to technical feat ure and a pp lication effect of intelli g ent cont rol s y stem successf nll y a pp lied tO p rocessed alumina sinterin g rotar y kiln in certain com p an y.【Descri p tors】Intelli g ent conlrul Processed ahnnine sinterin g Rotar y kiln ModuleO p timization Test on t he St ruct ural Parameter of Se p aratin g Box where Im p urit y Is Washed awa y f rom Ext ract Coal..HE Xiu j uan et al.(58-59) Ado p tin g t he similar simulation met hod,a laborator y model has been es2 tablished on t he basis of ori g inal box where wood and coal are se p erated,t he o p timization test to t he st ruct ural p arameter of se p eratin g box has been done.The result shows t hat t he ex p ectant g oal to reduce im p urit y clearl y wit h little coal can be achieved.【Descri p tors】Se p aratin g box O p2 timization test St ruct ural p arameterCommon Techni g uesDevelo p ment of Shot-Peenin g Stren g t henin g Machine and Its Technolo gy..........................DON G Xin g et al.(66-68) The p a p er anal y zes t he technical feat ure of shot-p eenin g and indicates t he limitation of t raditional techni q ue.It also st ud y s t he advanta g e of st ren g t henin g techni q ue wit h hi g h-p ressure water j et,in addition,t he current sit uation and develo p in g t rend of shot-p eenin g st ren g t henin g machine and it s technolo gy are stated in t he p a p er.【Descri p tors】Shot-p eenin g st ren g t henin g Shot-p eenin g e q ui p ment Water j et Fati g ue life-s p anAdvance Demonst ration Met hod of Sit uation of En g ineerin g Machiner y Technolo gy Based on Emulation Technolo gy...WAN GJ ian et al.(68-70) The p a p er makes anal y sis on t he t heoretic develo p in g t rend and t he fea2 t ure of some advanced techni q ue a pp lied to t he field of armament desi g n, manufact urin g and mana g ement.Moreover,it g ives an em p hatic int ro2 duction to t he demonst ratin g met hod of virt ual technolo gy,which p ro2 vides t he new reason for test demonst ration and scientific mana g ement of en g ineerin g machiner y.【Descri p tors】En g ineerin g machiner y Virt ual technolo gy Test demonst rationRa p id Protot yp e Manufact urin g Techni q ue and It s A pp lication in Metallic Part Manufact urin g Indust r y.................SU Fa et al.(71-73) The p a p er int roduces t he basic p rinci p le,manufact urin g p rocess,char2 acteristics,sha p ed met hod of ra p id p rotot yp e manufact urin g techni q ue and it s a pp lication in metallic p art manufact urin g indust r y.It also indi2 cates t hat t he techni q ue is a new-t yp e s y nt hetical one b y which can ra p idl y manufact ures p rotot yp e and it s wide develo p in g p ros p ect.【Descri p tors】Ra p id p rotot yp e manufact urin g Dis p ersion De p osition Research on Qualit y Cont rol of Purchasin g Paris of Machiner y Product s Based on Fuzz y B P Model..............MA Xiaoron g et al.(73-76) The p a p er makes anal y sis on t he re q uirement s and p rocedure of q ualit y cont rol for p urchasin g p art s in t he p rocess of machiner y manufact ure. Based on t he t heor y and met hod of f uzz y-neural network,t he f uzz y B P model of q ualit y cont rol for p urchasin g p art s is established,and t he o p ti2 mal wei g ht s in t he p rocess of q ualit y cont rol are also determined 【Descri p tors】Fuzz y B P model Manufact urin g p rocess Purchasin g p art Qualit y cont rolA pp lication of Fuzz y-A HP in Pro j ect Preferance of En g ineerin g E q ui p2 ment S y stem Combination...............PU Chuan j in et al.(77-78) The p a p er int roduces t he p rinci p le of f uzz y hierarch y anal y sis met hod and t he basic p rocess of p roblem anal y sis.Based on f uzz y hierarch y anal y sis met hod,p ro j ect p referance of t unnel excavatin g e q ui p ment s y stem com2 bination has been done,and t he result s shows t hat t he anal y sis outcome accords wit h t he fact.【Descri p tors】Fuzz y hierarch y anal y sis met hod Trian g ular f uzz y number Pro j ect o p timizationA Novel To p olo gy of O p timal Harmonic Inverter wit h Hi g h Volta g e and Heav y Power.......................J IAN G Ynuhua et al.(80-82) The p a p er describes a t ravel t nulti p lex To p olo gy,makes anal y sis and emulation to two kinds of volta g e harmonic and current wit h different st ruct ure,and t he result s confirm t he feasibilit y of t heor y.【Descri p tors】Multi p lex Harmonic GTOinverter I GB TinverterDevelo p ement of Dislributed Processor Feedin g Cont rol S y s2 tem..............................YAN G Shu y an et al.(83-85) The p a p er g ives a det uilcd descri p tion to t he st ruct ure of dist ributed p ro2 cessor feedin g cont rol s y stem,hardware make-u p p rinci p le of feedin g cont roller and t he desi g n of communication software.【Descri p tors】Feedin g Distributed controllin g Monolit hic p rocessor Confi g uration king © 1995-2006 Tsinghua Tongfang Optical Disc Co., Ltd. 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