Abstract
Modern technological progress leads to increased complexity of engineering systems, processes, and products, posing significant challenges in proper design, analysis, control, safety, and production management. On the other hand, it should be emphasized that the chemical process is basically nonlinear, which is manifested mainly in the response to malfunction changes in operating parameters. While a small change in an operating parameter can cause large, hard-to-predict, process response (unpredictable course of temperatures, pressures, levels, ...), these nonlinearities can also lead to cumulative effects in the occurrence of several fault changes which can spread in many ways and even cause system failure. Nonlinear interactions between interdependent components can lead to unexpected (unpredictable) behavior and should be taken into consideration during process hazard analyses such as HAZOP. Nonlinearity of the system's response can be manifested by high sensitivity to changes of design parameters, oscillatory behavior, or domino effect due to a different steady state reached. Knowledge of the nonlinear process response to deviations of various design parameters in different parts of the process provides significant added value in the development of unexpected scenarios of deviation-cause-consequence chains. This paper presents evaluation methods of nonlinearity indicators in chemical processes during HAZOP study based on the time response to the deviation of single or multiple parameters calculated by Aspen Plus Dynamics v14. and Matlab tools.
