2005 Annual Meeting
(552e) Web-Based Remote Experiments with a Real Technical Plant in Chemical Engineering Education
Authors
In the field of process and plant technology teaching, practical experience plays an important role. Since practical training is also a very time consuming task for both, students and teachers, and therefore often neglected, at the DBTA (Department of Process Dynamics and Operation) and the ZMMS (Center of Human Machine Systems) departments of the Berlin Technical University we are searching for new ways of giving access to our laboratories and integrating this field to the existing curriculum [2]. Web-based technologies enable the implementation of remote experiments with real technical plants or laboratories for engineering education.
In this paper we present a web based laboratory [3] used to access chemical plants. The process used for this experiment is composed of a distillation column for ethanol-water mixture with 20 glass-trays and a video camera for visualisation. The distillation tower which is 3.5 m high and has a diameter of 35 mm is automated and controlled by the PCS (Process Control System) ABB Freelance 2000TM. To facilitate interoperability with other applications, Freelance includes an OPC-server which is based on the DCOMTM standard. The figure shows the web interface and the on-line column.
On the client-side, we use a proprietary developed JavaTM-based experimental PCS called PE/SSE (Process Operation Education and Training/Small Systems Edition) that is able to run the user interface embedded in web browsers [6]. The data-exchange between the GUI and the PCS core is based on an open internet protocol for process data transport (PDTP) [4]. To connect Freelance2000 to the PCS core we implement a bridge between the client side and the server-side process control systems. This architecture ensures scalable and reliable access to our laboratory resources.
The PE/SSE-GUI has the same structure as a process visualisation system with some additional abilities. On the one hand, the GUI can be run either as a standalone program on any operating system or embedded in a web browser as a Java-applet. On the other hand, we have implemented many add-ons for different purposes, e.g. integrated adaptive information and support depending on process data or alarm information. It is also possible to integrate the GUI into a learning management system in order to solve exercises concerning the online column. The GUI must be programmed in Java for every new problem. Therefore, a library of templates is implemented into the PE/SSE-environment.
The experimental PCS that is already used for browsing e-learning materials and running process simulations is in this way extended to connect to real processes. With this integrated approach, we expect to close the gap between theoretical and practical experience in teaching process and plant technology.
First evaluation of the tool is made by Gauss [1]. The students in the role of operators have to identify and to fix two disturbances affecting the proper operation of the column. Therefore, the students have to detect the irregularities in the related trend diagrams and gather the correct malfunction cause. At least, the students should initiate the correct reaction and bring the process back into a steady state. The troubleshooting scenario supports the students to go deeper into the relation of theoretical modelling and the physical behaviour of the real process. As the students operate the process, they get a new perspective on theoretical learning content. The results of the evaluation study indicate that the learning scenario was highly accepted by the students [1,3]. Troubleshooting performance was influenced by intrinsic motivation and information processing velocity of the learners. The effect of troubleshooting on learning outcome was slightly positive.
A didactical scenario with a troubleshooting task has been created to be realised with the online column. In a controlled study, the acceptance of the scenario and its effects on learning outcome are positively evaluated [1].
At the DBTA, online experiments are integrated into existing courses, where the lecturer can access the online column from a lecture, as well as into practical exercises, where students can handle the column themselves to see the effect of certain disturbances on the hydrodynamic, energy balance and the product quality. The results of the experiments can be taken over into MS EXCEL and there be analysed. With this experiment, practical process knowledge can be transferred to the students inside the universitary learning environment.
References
[1] Gauss, B., Klein, A., Urbas, L., Zerry, R. & Wozny, G. (2004) Learning by troubleshooting ? a suitable didactical scenario for online experiments?, INCOM 2004 - 11th IFAC Symposium on Information Control Problems in Manufacturing, 5 -7 April 2004, Salvador, Brasil
[2] Wozny, G., Klein, A., Zerry, R., Hausmanns, C. & Urbas, L. (2004) Improvement of learning of process technology using modern information technology, PRES 2004, 7th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, 22-26. August 2004, Prag
[3] Klein, A. Hausmanns, C., Urbas, L. & Wozny, G. (2004) Internet-based Learning ? the online laboratory Distillation column, EDEN 2004 ? Annual Conference 2-6. June 2004, Budapest
[4] Urbas, L., Entwicklung und Realisierung einer Trainings- und Ausbildungsumgebung zur Schulung der Prozessdynamik und des Anlagenbetriebs im Internet (Development and realisation of a trainings environment for process dynamics and operation via internet), VDI-Fortschrittsberichte Reihe 10 Nr. 614 1999
[6] Klein, A., Zerry, R., Hausmanns, C., Urbas, L. & Wozny, G. (2003) Java based Process control of a distillation column via internet using OPC; ECCE-4, Granada [Spain], 21-25. September 2003.
