Design Approach to Synthesize, Validate, and Evaluate Operating Procedures Based on Timed Automata and Dynamic Simulation

• Main Authors: Chun-RenZhang, 張淳仁
• Other Authors: Chuei-Tin Chang
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/7upubw

碩士 === 國立成功大學 === 化學工程學系 === 107 === Despite the fact that the modern chemical plants are becoming much more complex than they used to be, their operating procedures are still generated manually in most cases. Since this approach is clearly laborious, time-consuming and error prone, it is necessary to develop a viable approach to systematically and automatically conjecture a set of reliable control actions to perform various tasks in realistic chemical processes. With timed automata and dynamic simulation, the tasks of synthesizing, validating and evaluating operating procedures have been accomplished in this work. Specifically, the following steps are carried out: First of all, it is necessary to discretize all state variables in the given system and then build the untimed automata for modeling the basic components according to generic engineering knowledge. Secondly, the elapsed times of all possible state transfers for every processing unit can be determined with Aspen Plus Dynamics and the corresponding timed automata can then be built to model these units. Next, after identifying the critical stages of the entire operation, one can stipulate the control specifications of each stage and build the corresponding automata. All automata built above should then be integrated and synthesized into a system model. Consequently, the shortest or quickest trace in the system may be extracted with UPPAAL and every trace summarized with a sequential function chart (SFC). Finally, the SFCs should be verified with Aspen Plus Dynamics. If the simulation study confirms that all SFCs are unsafe and/or infeasible, one should modify/add/remove the control specifications and repeat the aforementioned synthesis steps. The above procedure has been applied successfully to three examples, i.e., the start-up operations of a continuous flash drum, a continuous distillation column and a continuous reactive distillation column.