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Introduction

The advent of powerful and friendly integrated software has movedadva nced process control (APC) from the realm of consu ltants into thearena of the ave rage process control engineer. The obstacles of infrastructure and special skill requirements have started to disappear and we arepoised for an accelerated application of APC .It is well kno wn that APC seeks to discover, incorporate, an d exploitknow ledge about raw materials, process, produc t, equipment, instrumentation, and final elements. What is not often recognized is the significantincrease in the kno wled ge base of both p lant an d field opera tions th atoccurs as the APC system is developed . In fact, an appreciable po rtion ofthe benefits are achieved by im provem ents m ade in operating procedu res,set points, sensors, an d con trol valves as a result of the m ethodical analysis,testing, mo deling, and prototy ping that are part of the best practicesuse d in the imp leme ntation of APC systems.Until recently, mo st of this know ledge en ded up with co nsultants, and thesuccess of the application often deteriorated once they de pa rted. There isno w a n opp ortu nity for the engineers closest to the process and dailyoperations to take a much m ore active role in the developm ent an d sup po rt of APC applications. It is a win-w in situation in th at the cost of APCcan be reduced by using consultants primarily in a higher-value-addedrole of conceptual design a nd o ptimization. Even mo re impo rtantly,greater und erstanding , supp ort, and involvement of onsite engineers canincrease the success rate, the on-stream time, and the longevity of an A PCapp lication. This decrease in the cost an d inc rease in the benefits w ill intur n lead to a larger num ber of successful A PC installations and a greaterinterest in APC as a me thod of impro ving process efficiency and capacity.

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dvanced Control Unleashed

However, much of the purpose and use of APC has been clouded in theory. The theory is scattered am ong m any bo oks written for g rad ua teschool prog ram s in advan ced p rocess control. App lication pa pe rs typically concentrate on the benefits of specific A PC projects and serve m oreas advertisem ents for particular consulting or software firms than asimplem entation guid es. Little if anythin g ha s been written for the practicing engineer on ho w to select, design, configure, commission, and tun eAPC system s. The purp ose of this book is to demystify APC an d m ake itmore accessible.Tothat end , the book focuses on practice and applicationsbacked up by eno ugh theory to insure a deeper u nderstan ding.Each chapter is organized to pro vide concise practical information that auser can readily explore and reference to start and complete a successfulimplem entation. Each chap ter has three major sections, entitledP racticeApplication and Theory.ThePRACTICEsection starts w ith anOverviewthat prov ides a conciseexplanation of the technology an d its impo rtance. It pro vid es the m otivation and basis for investing more time in learning and p urs uin g the technology. Next is anOpportunity ssessmentsubsection that offers a simpleapp roach to determ ine whe ther the technology is applicable to a particularun it ope ration. It consists of a set of concepts and questions to start thethou gh t process and discussions to find potential applications. The Exam-plessubsection rou nd s out the section. The sam ple of applications presented here help to instill a better practical unde rstan din g of the use of thetechnology in the process indu stry.TheAPPLICATION section starts with aGeneral Proceduresubsection thatpresen ts a go-to checklist to introduc e the user to the no rm al sequenceof even ts for a successful app lication. This list pro vid es a good reference toma ke sure all bases are covered an d is useful for plan ning , schedu ling,estimating, and m onitoring A PC projects. Next there is an pplicationDetailsubsection that sum marizes m ost of wh at a user need s to know. Abuilding-block appro ach is used whe rever possible, starting with a basicbare-bo nes application and ad din g successively mo re capabilities to en dup with a full c omp lement of advan ced features. Next is a series ofRules ofThumbconcisely ph rase d to be readily referenced and remem bered. Abrief ex planation w ith an y notable exceptions follows each rule. The section end s with aGuided Tourto give the reader a feel for how adva nces insoftware have made implementation easy enough that the user can focuson the o ppo rtunity offered by these APC tools to discover, incorporate,and exploit plant know ledge.The THEORYsection presen ts the major facets of selected app roache s to thedep loym ent of each APC technology as part of a state-of-the-art tool set.

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Chapter Introduction 3

For brevity, the section doe s not surv ey all the possible me thodolog ies an dtechnique s, bu t focuses on those that are innov ative and sim ple enou gh tobe integrated into a distributed control system.This book c overs a great deal of gro un d. Each of the technologies discussed he re could easily fill a book initself.However, users today do n'thav e th e time or inclination to read a lot of material. Lists, hints , rules ofthum b, and concise explanations are employed to save the reader time andto provide both a better perspective on the who le picture and an improvedability to drill do w n to obtain specific implem entation g uidan ce. The bookconcentrates on wh at is mo st impo rtant. Users can quickly get to the hea rtof the matter without getting lost in the details associated with a specifictool or suffering from information overload.W hile a user can go directly to a given chapter to learn abou t a particulartechnology, the auth ors recom men d tha t Chap ters 2 and 3 be read first.They provide the necessary foundation on which to build an APC application an d th e logic to select the most ap pro priate technology.Included with the book is a compact disc that contains a set of exam ples ofthe technologies discussed in the book. They dem onstrate, by m ean s of astep-by-step procedure and a detailed dynam ic process model, how toconfigure, test, and r un eachAPCapplication. Con figuration an d case filesuse a virtua l plant that ha s a complete scalable Distributed Con trol System(DCS) with a suite of APC tools and a high-fidelity plan t simulation.A co mp anion set of Pow er Po int slides that illustrates all of the major Figures,equation s, tables, lists and ru les included in the book is on th e CD.These slides and the han ds-on exercises mak e the book p ractical as a textboo k for courses on both basic and adv anced process control. Ch apters 2and 6 receive the most extensive treatment becau se introductory coursesare most comm on. Also, stud ents an d u sers alike need to first co ncentrateon getting the basic regulatory con trol system design ed correctly a ndtuned properly before mov ing on to more advanced topics. Most of thematerial has been tested in an introdu ctory co urse on process control forjunior a nd senior chemical engineers at Washington Un iversity in SaintLouis.These students have de mon strated the ability to immediately a pplythese APC tools to example pro blem s after a brief tutorial, usin g theircom puter skills and a powerful integrated Windows environme nt. Thesound mathematical foundation ofAPCmakes it easier to learn tha n basiccontrol, wh ich is mo re heuristic.

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4 Advan ced Control Unleashed

The tutorials and presentations on the CD do n ot require any special software or hard wa re beyond a PC with a media player, speakers, and a display with a screen area of at least1 24by768pixels.This book w ith its appendices a nd CDs should en able the average p rocessengineer to deve lop a good un der stan din g of the represen tative principlesand techniques ofAPC.This knowled ge w ill be helpful in setting objectives,evaluating potential APC opportunities, and applying the mostapp ropr iate APC technologies. Readers sh ould feel free to contact theauthors at theire mailaddresses if they have any questions about the useof the book, exercises, dem os, slides, or APC tools desc ribed.All royalties from this boo k will be give n directly to universities , consortia,and ed ucational program s to promote and enhance the developmen t an duse of adva nced process control. A beneficiary of each ye ar's royalties w illbe chosen by the authors.