Topic: Contribution of process simulation to the safety of industrial plants
Speaker: Prof.Siméon Cavadias
Time: 12:40-14:00, Friday June 9th, 2017
Venue: F309 in the teaching building, Zhuhai Campus, SYSU
Organizer: Sino-French Institute of Nuclear Engineering and Technology, Sun Yat-sen University
Computer controlled processes are becoming increasingly important in the quest for higher productivity, greater efficiency and safety. Chemical industry has benefited from the appearance of computers and the increase of their power over time. This increase of the computation power allowed the simulation of chemical processes more and more complex with a good accuracy.
The computation capabilities in the 80s, allowed the simulation of a steady state (static simulation) production unit, which consists in solving a system of algebraic equations resulting from material and energy balances.
For the last fifteen years, it has been possible to add to the algebraic equations, differential equations, representing the variation, over time, of the temperatures, pressures and concentrations (dT / dt, dP / dt, dCi / dt ...) and resolve them in real time. Thus it became possible to simulate the start-up, the shutdown and real-time operation (dynamic simulation) of a unit. The simultaneous resolution of all equations (algebraic and differential) in real time, allows the monitoring of the plant.
Computers offer potential advantages in safety by providing closer supervision and better information of the process; by monitoring critical parameters and, when circumstances warrant it, initiating and carrying out a safe shutdown.
In particular, it is possible to predict the consequences in case of deviation of the temperature or the pressure from the nominal value at any point of the unit. The operator can take the necessary measures to handle the incident, thus ensuring safety of personnel and the environment. In addition, the staff can be trained on different incident scenarios, assess their severity, and consider the adequate and possible solutions.
To illustrate this approach, an example is given of simulating a polymerization reaction, which is highly exothermic and therefore requires very powerful cooling. During the polymerization, which lasts for 33 hours, a shutdown of the cooling pumps for 5 minutes is simulated, which causes the runaway of the reactor. The consequences of this incident are analyzed and commented.
Such an incident can occur also at a nuclear power plant, which is close in terms of the extent of heat flux.
About the speaker:
Siméon Cavadias, professor of University of Paris 6 and Chimie-Paritech. He received Doctorat d’Etat ès Sciences from University of P. et M. Curie (Paris VI) in 1987.
His research interests are Plasma processes for depollution，Plasma catalysis for conversion of energy，Modeling of plasma chemical processes. His teaching activities focus on transport phenomena, unit operations and modeling of chemical processes.