PiControl is a leader in developing and selling process simulators for laboratories and chemical plants. PiControl possesses a distillation simulator. The distillation simulator is a real-time dynamic simulator. Other process simulators and laboratory simulators include: heat exchanger simulator, turbine simulator, compressor simulator, pressure drop in piping simulator, agitator mixer simulator, reactor simulator and many other laboratory process simulators and chemical plant simulators.
PiControl is developing a complete Styrene Monomer Plant Simulator software that is very modern, far more compact and practical compared to other approaches. PiControl will use the very popular Siemens PLC and then customize with standard and custom function blocks supplemented with Visual Basic or C/C++ custom logic. The design and implementation will be very practical, producing a platform very closely mimicking a real plant with a real control room environment.
Styrene Monomer is an excellent process for student learning and experience. This is because Styrene Monomer process has a rich combination of process equipment providing several diverse unit operations experiences for the students. The process simulator will be made to look very realistic and to an observer standing in front of the HMI (human machine interface) screen, will feel as if he or she is in a real control room in a real plant.
The process will comprise of a Main Steam and EB (Ethylbenzene)/Steam Superheaters, two-stage dehydrogenation reactor, a complex, tall (250 feet) super-fractionator – EB/SM splitter, and two more distillation columns, namely - EB Recovery Column, SM Column and also a Thin Film Evaporator (TFE). Detailed process details and controls on the distillation feed, reflux and reboilers will be provided. Utility equipment with HMI graphics comprising of cooling tower, steam generator and peripheral units will also be supplied.
If the student makes mistakes that produce dangerous operating conditions, then automatic shutdown logic in the PLC will gracefully trip portions of the plant as needed. First-out trigger will be displayed on the alarm/message summary screen indicating the cause of the shut-down. The entire plant will not be tripped unless this is necessary for safety.
An emergency shutdown button will be provided. This button will have both software click option on the HMI screen and also a hard-wired panel mounted physical button.
Either a software click, or the pushing of the physical button will trip the entire plant and all control valves will be forced into their fail-safe positions.
The simulator will comprise of about 50-75 PID control loops including flow controllers, temperature controllers, level controllers, pressure controllers, online analysis controllers and compressor surge controllers.
There will be several pumps, control valves and various HMI options for the students to change the mode from manual to auto to cascade, change setpoint in auto mode, change control valve position in manual mode, start and stop pumps and compressor.
Approximately 10 PLC HMI graphics will be provided covering all process equipment, utilities, tank farm and OSBL. From these HMI graphics, students can navigate from one equipment to another, go to utilities and back to process, start/stop pumps and do everything necessary to monitor, operate and run the plant.
The project will include two types of advanced process control (APC) – DCS-based APC and Model Predictive Control (MPC).
The DCS-based APC will comprise of the following:
- Cascade control
- Feedforward control
- Ratio control
- Constraint override control
- Adaptive control
- Inferential control
All these APC schemes will be developed and implemented inside the Siemens PLC.
In today’s world, MPC (Model Predictive Control) is also very popular. The project will try to install an MPC software like Aspen DMC, Honeywell RMPCT or Yokogawa Shell PACE/SMOC.
Students will be able to conduct step tests or even use closed-loop data using PiControl’s PITOPS software which is a powerful modern tool for both open-loop or closed-loop system identification, PID tuning optimization and for the design of parameters comprising of the APC schemes. One license of PITOPS-OPC and another of PITOPS-EXCEL will be provided as part of this project.
Modern plants that are well run are equipped with Control Loop Performance Monitoring (CLPM) software. PiControl will provide one license of APROMON software (Advanced Process Monitoring) that will connect directly to the Siemens PLC using an OPC server. APROMON will run every 24 hours automatically, analyze historical data for all PIDs and APC schemes in the whole plant and then display control loops that are not tuned well, PV sensors that are noisy, bad control valves – valves that are sticking and loops that are in manual for too long (having low onstream factor).
Modern plants have various software tools for data collection trending, monitoring, archival, optimization, model calculations and APC parameter calculations. To support these tools, an OPC server will be provided.
For more details, visit www.picontrolsolutions.com and send an email to [email protected].
