Commercial simulation programmes in the performance analysis of controllers applied to a plate type heat exchanger

Abstract

Conventional feedback control and cascade control strategies were applied to a heat exchanger in order to compare the control performance in terms of deviations of temperature and settling time, under different plant disturbances. The plate type heat exchanger was designed by using the software ASPEN HTFS®. With the help of ASPEN PLUS®, the steady state was found and the simulation exported to the ASPEN DYNAMICS®. The process reaction curve method was then carried out. The parameters of first-order-plus-time-delay (FOPTD) transfer functions were determined for the process and also for the load disturbances. In the Simulink/MATLAB® environment, feedback control diagrams were built employing these transfer functions to find the closed loop responses. The same methodology of use of commercial simulators can be applied to different unit operations of the chemical industry, as well as for plant-wide problems. It must be pointed out that, since they have friendly interface, access to thermodynamic data and robustness in the available numerical methods for simulation, an easy use and a steep learning curve were noted for all the commercial simulators employed in the present work.