22nd AFA Int’l. Fertilizers Technology Conference & Exhibition

June 30th - July 2nd, 2009

Marrakech, Morocco

Process simulation tool as an approach to safety enhancement

Micheal Kartoveschenko Deputy Commercial Director for Int. Business JSC NIIK,

Research & design Institute of Urea and Organic Synthesis Products

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JSC NIIK, Research & design Institute of Urea and Organic Synthesis Products, Russia

Process simulation tool as an approach to safety

enhancement Introduction In our paper we would like to dwell upon educational aspect of production safety

enhancement. It is well known that personnel qualification is a driving factor of industrial stability and reliability.

The issue of teaching in the meaning of knowledge transference from tutor to pupil has been historically significant. Psychologists proved the fact that trainees digest 20% of what they see, 40 % of what they see and hear, and 70% of what they see, hear and do. It is evident that activation of all sensory organs by means of multimedia tools ensures maximum efficiency of training.

In this regard, simulator as a tool for generation of professional skills satisfies all necessary requirements and is known from the ancient times. Evolutionary simulators appeared to be most demanded in the fields with significant influence of human factor: armament systems, aviation, ship navigation, atomic power stations, and complicated explosion risk production plants.

Nowadays the relevance of simulators has even increased. The necessity of simulators

application in various explosion risk production plants is fixed in many countries by governmental regulations.

This in many cases is justified by the fact that the main cause of accidents at the mentioned type of plants is human factor.

The recent tendencies for increasing of production capacity result in the increase of errors’ cost in case of accident. This fact inevitably leads to the increase of personnel training significance.

The most efficient tool for personnel training is computer based simulator where all available multimedia means are applied.

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ROLE OF QUALIFIED PERSONNEL PREPAPRATION FOR COMPLEX INDUSTRIAL PLANTS

Personnel training for complex industrial plant to which, for example, urea production can be attributed, is very actual due to the number of reasons where safety and economic efficiency requirements are in the short list.

Introduction of automated process control systems and improvement of control loops that lead to decrease of start up/shut downs and accident number, and, despite it may seem paradoxic – decreases level of operators practical skills and degradation of their respond ability in emergency situations. Training with simulator ensure preserving of qualification and even developing of professional skills such as operators’ actions in process emergencies and generation of process control strategies for normal operation mode.

The mentioned benefits are enabled by database containing large volumes of technical information about urea production process. This highly improves technical literacy of the process personnel. Significant number of calculated indices of urea production process available for a trainee ensures safety and improves economic performance of the plant.

The example may be the following: It is known that СО2 conversion rate into urea is one of the most important qualitative parameter of the process, which is not automatically controlled in the real production loop. Without knowledge of these interrelation of parameters and control actions it is impossible to educate personnel with adequate quality of how to control this main stage of the process.

PC based process simulator developed by our company gives trainee the mentioned

possibilities.

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BREIF DESCRIPTION OF UREA PROCESS PC BASED SIMULATOR DEVELOPED BY R&D INSTITUTE OF UREA AND ORGANIC SYNTHESIS PRODUCTS

Structurally simulator is an integrity of server, identical workstations of trainees and tutor communicated via Ethernet. PC based simulator has the following structure

Functionally it is divided into: • Theoretical knowledge data base or electronic documentation; • Training subsystem for operating personnel;

o Normal process operation and control; o Failure process operation and control; o Start up and shut down control;

• Subsystem of testing and certification.

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Electronic documentation Electronic documentation contains systematized information about process procedures,

instruction for workstations, relevant occupational regulations, process diagrams with instrumentation, sectional views of process vessels with animation of flows and other process data.

The visual teaching of the process is ensured by means of interactive diagram of automated control system enabling trainee to find equipment position and study its operation principles.

Electronic documents contain references to process diagram, vessels, process stages and material flows.

The existing index of equipment positions (section “Equipment”) easily navigates trainee in the process diagram.

Thus, electronic documentation is very convenient tool for both primary teaching of employees and periodical qualification improvement.

The described option provides employee with good comprehension of the process and prepares for work in real operation mode.

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Screen shot example of menu with animated operation of washing column

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Screen shot example of incontrollable multi component flows visualization in process pipelines

These options of simulator provides prospect operator with information and procedural

adequacy of automated control system imitation and interface to the real interface of existing on the plant automated control system.

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Teaching subsystem

Teaching of process control in normal, start up, shut down and emergency conditions is based on the mathematic models of production process and automated control system.

Simulator is based on static and dynamic models of process loops. Models in their turn are built on description of material and heat balances of vessels and process stages as well as description of control loops by means of differential equations.

As for automated control system it is simulated by control algorithms very similar to those of the real control system applied for the certain process.

A very attractive feature of simulator is its possibility to ensure control of multi element flows inside of vessels and pipelines and flow rates of such elements. Moreover, simulator ensures automatic control of the most important process parameters that are not normally measured by instruments.

This enables a trainee to study statics and dynamics of process as well as respond to control actions, improving, thus, control skills of complicated chemical production process.

Subsystem of testing and certification The subsystem of testing and certification gives personnel possibility to test the acquired

knowledge of process control in different operation modes including emergency. This system also helps management to certify employees knowledge with proper reporting on level of their qualification.

All tasks are compiled according to professional instruction of senior operation manager.

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JSC NIIK has developed and realized in 2007 a full scale urea process training and

simulation complex at JSC NAK AZOT production plant of Eurochem company(Russia). Development, realization and commissioning took 1 year.

Basic stages of simulator development are the following: - approval of technical requirements and development of technical order for simulator: - development of electronic data base (electronic documentation); - development of process and DCS imitators; - development of interface server software; - development od teaching and certification system. The most attractive and useful features of such simulator are the following: - full scale dynamic mathematical model; - calculation of parameters that are not controlled automatically; - calculation of component consumption in gaseous and liquid process flows. Additional calculated data ensures obtaining while teaching process more confident control

skills, by using process imitator responds to interference of operators.