#
Virtual Lab for Chemical Process Control: Bridge the Gap between Lectures and Hands-on Experience

Virtual Lab for Chemical Process Control: Bridge the Gap between Lectures and Hands-on Experience

Course Name & Description: CHE 460 Chemical Process Control

Project Abstract: The significant gap between theoretical concepts and real control system is the major issue of learning CHE 460: Chemical Process Control. Due to large enrollment, limited lab time/facility and high operating cost, students do not have chance to manipulate real process units, implement any control methods in practice and do the troubleshooting during the class. This bottleneck renders students hardly connect the principles of mathematical theory with real systems. More seriously, without practice on real systems, students cannot realize the safety issue of their operations and design. In this project, PI will design a virtual lab by using SIMULINK 2D/3D animation and machine learning toolboxes in the MATLAB for CHE 460 to bridge the gap between theory and practice. The program contains front-end with interactive 2D/3D animations of typical process units and back-end with mathematical models identified from the real process data. The students’ design will be evaluated by machine learning tools to find potential flaws or safety issues. Our unit operations laboratory has the pilot-scale heat exchanger and distillation column. PI has collected a large amount of operating data and built accurate models for those units in research papers. The combination of interactive 2D/3D-animation with these mathematical models will enable students to learn, design, practice and debug their control systems for processes at any time and cost-free.

Keywords/Tags: MATLAB, 2D/3D Animation, Heat Exchanger; Instructional Delivery: In-class

Pedagogical Approaches: Active Learning, AR/VR, AI

**Background on the Redesign**

**Why Redesign your Course?**

- The course CHE 460 covers process dynamics and modern control theory with application to industrial processes. The students are required to describe the dynamics of a process using basic knowledge of mass and energy balances learned in previous classes. Typical models of process dynamics and their responses to various inputs are covered. With the modern theory of process stability, students will learn how to select the controller structure and parameters to suit process needs.
- The learning problem of CHE 460 is that students cannot apply their knowledge to design a practical control system, due to the high-volume enrollment and limited facility in the unit operations laboratory.

**High Demand/Low Success/Facilities Bottleneck Issues**

- Due to high enrollment (30~60/semester) and limited facility (1 heat exchanger, 1 distillation column) in the Unit Operations Lab, students cannot operate the real system and design its controller during this class. Without experimental education and training, students may only know how to solve mathematical problems, but lack of knowledge for real applications.

**Course History / Background**

- The CHE 460 Chemical Process Control is a gateway class mainly for fourth-year students. This class is traditionally taught through software EXCEL and Loop-pro. After 2017 Fall, Dr. Yu Yang has modified the curriculum to introduce MATLAB into this class. However, students still have strong desires to use the actual systems for learning.

*Syllabus from pre-designed course:*

**Student Characteristics**

- Every semester, about 40 to 60 fourth year students will attend this class. All of them are required to take the reaction kinetics and heat transfer courses as a pre-requisite. However, most of them may not have (1) strong mathematics background, (2) programming skills, and (3) experiment experience.
- 2020 Spring (Using VR): 29 enrolled. Female: 14, Male 15; All senior students.
- 2019 Fall (Without VR, control group): 61 enrolled. Female: 19, Male 42; All senior students.

**Advice I Give my Students to be Successful **

- Learn basic programming technique. For the new generation of workforce, computer programming is an essential skill for any major.
- Take more time to understand the chemical process itself. Control systems are designed for processes. Without solid knowledge of process, the controller design could be unrealistic.
- Learn how to analyze the experimental data. Data science right now is a hotspot and important for engineers to understand the actual performance of systems.
- Mathematics is important. Even though we can use computer, it is of importance to understand the mathematical concepts behind those programs.

**Impact of Student Learning Outcomes/Objectives (SLOs) on Course Redesign**

- Be able to use modern programming technology, such as MATLAB.
- Be able to use data-driven method to construct a process model, such as the transfer function
- Be able to design a PID controller with desired performance
- Be able to draw the P&ID diagram for a process from scratch.
- Be able to design a safety-oriented control system

**Alignment of SLOs With LIT Redesign **

- The 2D/3D animation will help students to visualize the process without conducting the real experiment, and then enable them to draw the P&ID
- The simulator can provide a if-then learning environment for students to explore the safety-oriented design
- Students can obtain, analyze and model the data generated from the animation.
- The machine tool developed in this class enables instructor to learn the weakness of students from the data of homework, projects, and exams.
- The animation program will be open source, such that students can learn the basic MATLAB programming skills from this tool.

**Assessments Used to Measure Students' Achievement of SLOs**

- The homework, exam, and project are graded with the detailed analysis of the knowledge points related to the SLOs. The resulting big-data in two semesters (with/without redesign) will be analyzed to measure students' achievements.
- The computer workshop I, II, III will provide the testbed to measure the students' ability on the data-driven modeling, PID controller design, and control system development, respectively.
- Selected students will do the real experiments. PI will evaluate their design through the experimental results.

**Accessibility, Affordability, and Diversity** **Accessibility**

- The computer simulation provide a fair and convenient platform for students, especially the disabled students, to conduct experiments without entering the unit operations laboratory.
- PI will upload the instructions of proposed simulator onto the YouTube. The caption will be provided.

**Affordability**

- The proposed simulator and materials are free and open-source.

**Diversity**

- PI has already hired one female student: Boya Li to design the simulator.
- PI will hire a Hispanic student to assist making the Spanish version of the simulator instructions to enable a diverse group of students to use the simulator.

**About the Instructor**

- Name: Yu Yang.
- Research interests: Chemical Process Control, Optimization and Modeling; Data Analysis; Water Treatment; Power System Control.
- Professional Background: More than 10 years experience on the model predictive control design; More than 5 years experience on the global optimization.
- Teaching Philosophy: Using Mathematics to understand the concept of chemistry/physical phenomena. Using computer programming techniques to implement, test and improve students' ideas through a simulator.

**Curriculum Vitae**

- My C.V. with the details of my background and interests.Research Resume.pdf

**Implementing the Redesigned Course**

- In the control group (2019 Fall), students had a tour in the Unit Operations Laboratory. During this tour, I give them a 15 minutes presentation to introduce our pilot-scale heat exchanger. Then, I ask students to plot a schematic diagram of the heat exchanger and design its control system.
- In the redesigned class (2020 Spring), I only show the simulator without any explanation of the heat exchanger. During a 2.5 hour workshop #1, a questionnaire will be assigned to students to evaluate their understanding of the process. Students will draw the schematic diagram and find the corresponding part (such as the control valve) on the real heat exchanger, shown in the Figure below.
- In the redesigned class (2020 Spring), the workshop #2 and #3 will be delivered to students and let them design a PID control system by using the heat exchanger simulator. The best team will be selected to implement their controller design in the real system.
- In the redesigned class (2020 Spring), there are 29 students. Since these students are senior and have experience of using MATLAB, I decide to use MATLAB as the software of simulator development. Moreover, the learning curve of MATLAB is relatively smoother than other developing tools, such as Phyton.
- An important factor of using VR simulator is the safety. Note that operating the real chemical/energy process could be dangerous (high temperature/pressure) if a bad controller design is deployed. Hence, a pre-training to students by using VR simulator could protect our students from any safety issues.

**Additional Resources Were Needed for the Redesign**

- The instructor would like to contact the MathWorks Application Engineers for the technical support of our simulator development.

** Revised syllabus (highlighted by red color): ** ChE 460, syllabus, Spring 2020 (Redesign).pdf

** LIT Redesign Impact on Teaching and Learning**

- Due to the COVID-2019, the class is taught remotely, and thus students cannot come to campus and learn the class face-to face. Fortunately, the development of VR-lab enables students to run the experiment at home with limited directions from instructor. As a result, the CHE 460 does not significantly affected by the COVID-2019, and students achieved the desired learning outcome even better than the pre-redesign.
- Students use the VR-lab in the project 1 and 3 for process modeling and controller design. However, the knowledge they learned can be used in the Midterm 1 & 2, and final exam. Thus, the VR-lab can impact students final grade.
- The instructor supposes to teach the VR-lab at computer-classroom in campus. However, due to COVID-2019, the campus locks down and the instruction should be conducted through video, such as Zoom and YouTube.
- The following file is an example of student' project 3.document-7244027-20656716.pdf

**Assessment Findings**

- The following chart/data shows the student performance in CHE 460 pre-design and redesign. We found that the performance of top students does not change. However, the middle-level students can improve their grades significantly. Especially, the number of students ranging from 70-80 boosts from 23% to 48%. In addition, the withdrawn rate reduces from 8% to 0%. Due to using VR-lab, the projects 1 & 3 can be performed better than before. Thus, the students can see that their overall grade is improved during the class, and thus making students more confident to continue taking this class. Another remark is that due to COVID-2019, students have to learn the class remotely, which poses a great challenge to teaching/learning. Under such a difficult situation, the performance of students in the re-designed class still is better than the pre-design, which shows the benefit of using VR-lab in the chemical engineering class.

** Student Feedback **

- A survey of VR-lab is conducted during the class to collect students' feedback. The questions are about the students' perspective of using VR-lab in the class and comments to the simulator .
- Positive: 21, Negative: 6, No comment: 2
- Students suggestions: (1) More instructions of using VR-lab (2) Share the code of simulator (3) Better animation
- Even though some students still want to do the real lab, the pandemic enforces us moving the class to the online teaching. Thus, most of students finally would like to use VR-lab instead, and believe that I am doing a good transition from traditional classroom to online.

**Challenges my Students Encountered**

- Some students have limited knowledge on MATLAB, and thus cannot easily understand the procedure of the lab.
- To overcome such a challenge, I made videos to explain the VR-lab and let students to form groups such that at least one student in each group can use MATLAB to complete the project.

**Lessons Learned & Redesign Tips**

**Teaching Tips**

- Make sure that students can use MATLAB. If not, some pre-training is required.
- Maintain the code of simulator and make some modifications according to the demand.

**Strategies I Used to Increase Engagement**

- A competition is hosted to encourage students using VR-lab in their project. The best controller design based on the VR-lab is demonstrated on the YouTube, and such a team can get bonus in the final grade. Through this competition, students are more likely to focus on the project and studying the simulator.

**Sustainability**

- Since the simulator is built by my student and myself, we can continue this work to make VR simulator for more process units of chemical engineering lab.

**Instructor Reflection**

- I would like to share the code of this simulator to anyone who are teaching process control, chemical lab or heat transfer.