kbr-improved margins, safety and reliability

Chemical Engineering World | 52 | AUGUST 2010

Features

Successful start-up and safe, reliable operation of new and existing multi-million/billion

dollar investments are paramount in establishing the highest return on investment and shortest payback period. It is imperative that plant operators be intimately familiar with the process, its control system, and required procedures for operation, safety and maintenance, well in advance of the actual plant startup in order to minimize risk and maximize the probability of success. Operators and regulators are therefore increasingly relying on Operator Training Simulators (OTS) to serve this need.

As an example, one gulf coast

refinery has experienced more than four shutdowns of its FCC unit in one year due to improperly trained operation personnel. The productivity loss was very large compared to the investment required to achieve proper operations through implementation of personnel training. The Baker Report on the BP Texas City Fire [1] also cited that ‘advantages to the site from the use of simulator training would be significant’.

Other recent trends causing a heightened interest in simulator based training are

Rapid turnover of experienced operators Younger operators are less likely to stay in same job till

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retirement Rapid change in automation technologies Increased use of automation More advanced process control removes day to day interaction and hence preparedness of the operator to react to emergencies Need to reduce time required to certify operators for board level tasks Need to provide integrated training for board, panel and field operations Some investment banks need it to provide loans or loan guarantees Needed as part of overall ISO certification process

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Ravi Guddeti, Prakash Ramdoss, Javier Vazquez Esparragoza, Surajit Dasgupta

Simulation Systems

Improved Margins, Safety and Reliability through Licensor Developed Operator Training Simulators

Today’s economic, regulatory, and political drivers demand higher margins, more reliable opera-tions and improved safety records. Plant and organizational economics demand higher yields, lower costs and more throughputs. Regulatory/political bodies demand fewer plant upsets and safer operation. These all lead to tighter, more complex process control to improve operations and result in an ever-increasing need for properly trained personnel.

Features-Simulation Systems-Impr52 52Features-Simulation Systems-Impr52 52 8/25/2010 12:44:19 PM8/25/2010 12:44:19 PM


Features

OTS: Tool of ChoiceOperator Training Simulators (OTS) are increasingly becoming the tool of choice for enhancing operations training due to their ability to provide realistic environments for operators to practice all facets of operation before and after the plant is built without affecting actual plant operations. Well structured simulator based training programs are proving to be highly effective in supplementing classroom training and practical experience. Especially for first of a kind plants, simulator based training has become a crucial tool for early training of operators and for ensuring smooth, incident free plant startups and quicker time to steady state.

Existing plants can benefit from higher margins through improved operational efficiencies, safety and reliability. In this context, a process licensor developed OTS can provide significantly added benefits in terms of accuracy and fidelity by incorporating actual plant design experience and decades of control and operations know-how into the design of the OTS. All process licensors may not have OTS capabilities or expertise. This paper is focused on those licensors like KBR which have advanced simulation as a core competency in addition to all of the traditional engineering competencies.

An Operator Training Simulator (OTS) typically consists of a ‘high-fidelity’ or rigorous dynamic model of a plant connected to a dedicated Distributed Control System (DCS) console for training. An OTS effectively replaces the real plant with a ‘virtual plant’, ie a first principles based dynamic model which realistically and accurately predicts

responses of the plant. The operators then react to those plant responses in the same way as they would do in the real plant, thereby mimicking the actual operating experience. OTS therefore circumvents the limitations of traditional training and expedites the training process by providing a system that can be used repeatedly and reliably to train on all key operational aspects and procedures without disrupting actual plant operations. Thus, this motivates many plant managers to opt for operator training programs that included simulators to constantly hone the skills of their operators in handling not only abnormal (sometimes rare) plant upset situations but also the routine day to day operations, shut down and start up procedures.

A typical OTS consists of several simulation computers and DCS components networked together as a standalone system. The models are

developed from data derived from P&ID’s, process design simulation runs, and the particular control philosophies and design parameters of the plant. The models, for the most part, use first principles of engineering and simulate the operation of the plant in real time. Since the models are rigorous and fundamentally based, the OTS can also be used for limited engineering evaluations such as ‘what-if ’ studies and control system changes.

A typical architecture of an OTS is shown Figure 1. Thus, besides the plant model, the system typically also includes an Instructor Station, Field/Panel operations console, Engineering console, Operator Consoles and related components like printers and file servers. The operator training consoles mimic the full functionality of the actual plant DCS consoles thereby providing identical look and feel as the actual DCS.

Figure 1- A typical OTS architecture

TYPICAL FUNCTIONAL COMPONENTS OF AN OTS

Slmulation Components DCS Components

Printer Printer

Main Simulation PC&

Engineering Console

Controls Emulation PCS

DCS DatabaseServer

InstructorConsole

Field/PanelOperations Console

OperatorConsoles

Ethernet Hub



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The Instructor Station is typically provided with full capability for system control, model manipulation, creating training exercises, and the evaluation of trainee performance. These features are accessible through graphic displays, menus, submenus, and other standard user interface techniques. OTS systems generally also include full engineering capability to modify system characteristics, and add or modify the dynamic models as needed.

An OTS system is usual ly designed to be relatively simple to operate. Its operation is typically synchronized and controlled through a single user interface. For larger models, to maintain real time or faster performance, sometimes it is necessary to have capability for multi-cpu execution. This is done using client server technology by distributing the processing over several CPU’s and several cores depending on the workstation hardware selected.

The primary user is the Instructor with ability to run the simulator and guide operators through the training exercises. The systems are provided with default scenarios, critical to operations training, customized to the requirements for each simulator. Besides default scenarios, each system has built in capability to introduce arbitrary malfunctions for all equipment and instrumentation included in the OTS.

Typical OTS SoftwareToday’s state-of-the-art commercial OTS software is available from several vendors. Typical of software that can be used are INDISS, Unisim Operations, OTISS, VP-LINK, DYNSIM, and others. Each software

package includes an integrated set of tools for both engineering and instructor functions, an extensive library of standard unit operations and control system modules which

allows sufficiently detailed process models to be built very quickly. The software also includes latest innovations such as client-server technology to distribute OTS functions over multiple processors to build large models and increase execution speed.

Advantage OTSThe key benefit of OTS systems

is that each trainee can perform simulations of startup, shutdown, turndown, emergency and abnormal operations as many times as necessary independently without actually affecting the real plant or its control system. Trainees can also deal with a variety of abnormal and emergency situations which might not occur frequently in the actual plant. As an OTS allows this form of training to be repeated frequently, it is possible to keep the expertise level of operators at a high level and evergreen. The consistency allows plants to certify their operators in a methodical way and also allows them to retain the know-how of experienced operators in handling plant start-ups and shutdowns, since such events are typically infrequent once stable operation is achieved.

Ideally, process simulator training should be coupled with conventional classroom and on-the-job training to give operators deeper knowledge about the processes itself. The trainees can manipulate chemical and physical parameters such as ambient temperature freely and note their effects on the simulated process without causing any upsets to the actual operating plant. The trainees can learn to recognize

High fi delity OTS can also be used to validate the plant

design, such as to Investigate ESD system response to various trip conditions Design and test different control strategies prior to actual implementation Investigate the dynamic and operational effects of engineering design Review and/or develop the operating procedures

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Figure 2: Skill level of the plant operators over time with repeated OTS practice

Without Practice

Effect of Practice on Operator Skill

With Practice

Op

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tor

Skill L

evel

Time on Job

0 2 4 6 8 100

20

40

60

80

100



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warning signals in the simulated process, so they are better prepared to react to abnormal conditions when encountered on-the-job.

Thus, the long-term benefit of OTS operator training is a better and more consistently skilled staff as conceptually illustrated. In fact it may be conceptually possible to continually increase the skill level of the plant operators over time with sustained OTS practice.

OTS Incorporated Training Procedure

Faster and more effective operator training Reduced plant downtime and losses Improved plant reliability Improved on-stream efficiency Increased plant life expectancy Faster plant start-ups and recovery from trips Improved operator competency in dealing with contingencies and abnormal conditions

Advantages of Licensor Built OTSThe fidelity of licensor developed OTS systems may allow the user to more effectively replace the real plant with a ‘virtual plant’, which realistically and accurately predicts responses of the plant to a variety of upsets based on rigorous, first principles-based dynamic modeling that provides lasting value throughout the lifecycle of the plant. This is done for example using proprietary correlations for specific equipment and thermodynamic properties and reaction kinetics, and the focused design of the training scenarios tailored to the client’s plant.

A licensor OTS can provide

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useful insight of the complex plant operation. OTS can be offered as a component of an overall licensor training program. As the licensor is fully aware of the process and potential control issues, extended client participation during OTS development phase would not be needed.

Licensor Developed OTS Systems may Provide the Following Benefits

Custom Process ModulesThe licensor will typically have access to steady state design models, including the reaction kinetics, proprietary thermodynamic properties, proprietary catalyst behavior, etc. The knowledge can easily be migrated in building the high fidelity custom models, and thus, facilitating the precise training needs. This also helps in reducing development time and hence, decreasing the overall project schedule. In certain cases, high fidelity models can facilitate the conduct of ‘what-if ’ engineering studies, and the debottlenecking and troubleshooting of complex field problems, etc.

Shadowing of Actual Plant StartupSince Licensor built dynamic models can be expected to provide a higher fidelity simulation of both the process and the control functionality, it may be possible to extend the use of the OTS beyond operator training. Thus, the end user can use the OTS to shadow the actual start-up of a plant. The exact steps that are taken on the actual plant can also be taken on the OTS. The operations team (from the licensor and owner companies)

then can use the OTS to test any major steps before trying them on the actual plant. This gives the plant operations an ability to look ahead at certain difficult situations and be prepared.

Custom Scenario Training and Operator Certifi cationThe knowledge of the Licensor can be used in developing the OTS features and functions that are customized to the training requirements of the actual process rather than a generic one-size-fits-all approach.

Reduced Need for Client Technical ResourcesA key advantage of a licensor-provided OTS is that it is developed by people who are intimately familiar with the operating philosophies, control strategies and the training requirements of the process. Thus it is more likely to be designed correctly from the start and be more ‘fit-for-purpose’ than OTS systems developed by third parties who would not be as familiar with the plant details. This reduces the requirement for additional client resources to be assigned to manage and oversee the OTS development, which may be a significant benefit for large, complex projects.

Additional Benefi tsAdditional benefits can accrue as indicated below when the EPC contractor is also the process licensor

Concurrent Development with Detailed Engineering (quicker plant commissioning)

The OTS can be developed c o n c u r r e n t l y w i t h d e t a i l e d engineering. Even though this



Features

Author Details:Ravi Guddeti is Advanced Automation Specialist, KBR Technology, Houston,

TX USAPrakash Ramdoss, Technical Leader, KBR Technology, Houston, TX USA

Javier Vazquez-Esparragoza, Technical Advisor, KBR Technology,

Houston, TX USASurajit Dasgupta, Senior Technology Manager, KBR Technology, Houston,

TX USAEmail: [email protected]

requirement may pose significant challenges, it provides a unique opportunity for the OTS to provide value well before its use for operator training. The OTS can potentially be used to verify the DCS configuration, test the usability of the DCS graphics and layout, test the control strategy and ESD logic, and develop operations manuals and control system check out. Conceptually, this early testing can eliminate typical sources of errors and/or aggravation that may later cause delays during actual plant commissioning, thereby potentially shortening the time to steady state operation.

ConclusionOTS systems provide a versatile and

realistic environment for training of plant operators. Intensive training using the OTS, in conjunction with other process and operations training, prepares operating staff for a safe, smooth start-up and reliable operation of the plant. The simulator can also help develop operator skills over many years. However, the end user management commitment towards sustained OTS based training beyond startup is needed to maximize OTS effectiveness and return on investment. Licensor developed OTS can be of higher fidelity and customized better to actual plant requirements; thus, such systems can provide significant additional value beyond just operator training.

References[1] The Report of the BP U.S

Refineries Independent Safety Review Panel, James A. Baker III et al, page 157, January 2007

Environment Ministry Rejects Vedanta’s Plan to Mine Bauxite

New Delhi: The environment ministry has rejected a plan by India-focused mining group Vedanta Resources Plc to mine bauxite in Orissa.

The decision pertains to one mining site in Orissa where it runs an alumina refinery on bauxite imported from elsewhere in India. The decision was announced in a government statement. The company is facing regulatory hurdles in its bid for control of Cairn India, a potential deal valued at USD 9.6 billion. The Forest Advisory Committee had recommended that the ‘in-principle clearance’ to the mining proposal, put forward by Orissa Mining Corporation, be withdrawn.

Vedanta, through its subsidiary Sterlite India, has a joint venture agreement with Orissa Mining Corporation to mine the Niyamgiri Hills for bauxite. The panel has also recommended action against Vedanta Alumina Refinery at Lanjigarh. It has recommended that steps be taken against the

refinery for illegally encroaching and enclosing 26 hectares of forestland. This despite the fact that the environmental clearance was given on the condition that no forestland would be used. Two other violations have been cited.

One, the refinery’s capacity has increased from 1 million tonnes per year to 6 million tonnes without requisite clearances. Secondly, Vedanta refinery is currently sourcing bauxite from 14 mines, of which 11 do not have any environmental clearance and are hence illegal. The Forest Advisory Committee has also recommended that the state be heard before the minister announces his decision.


kbr-improved margins, safety and reliability

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