The Study of the Process Dynamics and Control of a Continuous Stirred Tank Reactor Using a Partial Simulation Technique

Abstract

The problem was to analyse the stability and
controllability of a continuous stirred tank reactor which
was effecting an exothermic reaction. The approach chosen
was a partial simulation technigue by which it was hoped
to retain some of the real plant characteristics whilst
eliminating some of the more undesirable aspects. [In this
way it was anticipated that the gap between the completely
theoretical approach and real plant analysis would be
narrowed.

The equipment. employed was a typical well stirred
vessel which received a flow of water representing feed to
the reactor. The vessel was cooled by water flowing through
a coil which was situated in the vessel. Heat equal to that
released from the exothermic reaction was generated by means
of immersion heaters. The kinetics were simulated on an
analogue computer which monitored the feed flowrate into
the tank and also the temperature of the water within the
tank. The computer was programmed with the idealised model
of the process's material balance and by continually
integrating this in real time it calculated the heat
generation for the current value of temperature and
concentration in the tank. This value was then transformed
into real heat release in the vessel by means of immersion
heaters through a servomechanisnm.

The stability and controllability of the partially
simulated stirred tank reactor was then investigated, the results being obtained in phase-plane portrait form. The control of the reaction temperature was effected by employing a standard feedback control loop in real plant hardware.


The research showed that the partial simulation technique offered more versatility than real plant analysis
whilst the outlay necessary to conduct the work was much
reduced. When compared with complete simulation it was
evident that the demand on computer space was much reduced
yet more of the real system character was retained.

Date of Award	1971
Original language	English