Computers & Chemical Engineering, Vol.24, No.2-7, 1497-1502, 2000
A development of experimental education program: computer control of multi-stage level control system
We developed an experimental education program and the apparatus with computer software for chemical process control. A multi-stage liquid level control system is chosen as a target process because it is one of the simplest chemical processes to understand. The target process is composed of one storage tank, two series liquid level tanks and one more interactive liquid level tank with an on-off solenoid valve at the position between the store tank and the first level tank as the actuator and a DP-cell at the last stage level tank as the liquid level sensor. The software is programmed under the platform of both DOS and Windows'95, 98, NT. It is composed of the real-time graphic view of important variables, data sheets, dynamic process flow diagram, manual setting of set-paint, manual operation of actuator, setting of control parameters, auto tuning module, zero-span, data editor, signal filtering, etc. The experimental education course was also developed and it consists of 3 or 4 weeks with 3 or 4 h per week program. During the first week, students learn the control system basics and instrumentation and how to realize and check the signal of important variables. At the second week, students learn how to identify the process with the relevant control models. During the third week, they learn how to tune the PID control for the target process. If instructors want to teach 1 more week they may assign students to the task of designing their own tuning parameters and compare their performance with the conventional tuning methods which were prepared in the developed computer software. We could confirm that the experimental education was very helpful to understand the process control theory for undergraduate school students through the survey and grading.