Dynamic Simulation

Abstract

Dynamic simulation is a computational tool used in process engineering to understand and evaluate the transient behavior of a process, as well as the response capability of its associated control system during a time-dependent perturbation.

The direct benefit of a dynamic study is that it enables insights into system behavior during specified transient scenarios or operating cases. This facilitates early optimization of a process during design, thus minimizing project execution and later operational impacts, by the assessment of extreme operating cases or upset scenarios. It also enables process engineers to review equipment design specifications, improve or even totally modify the control system long before startup, develop operating (startup or shutdown) procedures and anticipate and correct unsafe operating cases.

Some of the applications on current or past projects include:

Assessment of heat exchanger tube-rupture scenarios.
Depressurization calculations, allowing an accurate estimate of the relief rates and temperature excursions that can be expected.
Detailed relief load calculations. In many cases, a more detailed analysis of transient behavior leads to lower loads than determined with simplified methods, and therefore allows for a cost effective, fit-for-purpose design of the relief system.
Evaluation of compressor safeguarding.
Evaluation of control and/or safeguarding systems.
Evaluation of specific processes upsets and the mitigations for the upsets.

Fluor's dynamic simulation services compliment and strengthen our process design and engineering capabilities. Dynamic simulation can be implemented in the early stages of project development. This can reduce the costs of equipment as well as overall project costs, supporting Fluor's fit-for-purpose design strategy.

Fluor maintains a group comprised of thermodynamics and simulation experts from our offices around the globe. The group allows efficient communication and collaboration between offices on requirements of advanced simulation services and solutions.

Client Benefits

Fluor provides dynamic simulation services to our customers both through internal execution and/or by services subcontracted from specialized consultancy companies to ensure comprehensive and sustained support on equipment design, optimization, operating procedures development, operators training, existing systems validation/troubleshooting and minimization of costs of project, investment and operation.

Examples of benefits include:

Dynamic study of HCU unit allowed Fluor to set dual design conditions on equipment downstream of reactors, providing substantial savings on heavy walled alloy equipment and piping.
Dynamic study of compressor system confirmed the adequacy of the anti-surge valve capacity for upset conditions and exempted additional requirement of cold gas bypass valve.
Dynamic simulation allowed Fluor to recommend a common acid gas header for multiple sulfur recovery units for more operational flexibility and reducing the likelihood of flaring during upset scenarios.
Dynamic depressuring study helped Fluor to identify a low-cost design modification by allowing the use of carbon steel for shock row tubes in steam superheaters.