Presentation
- 2. The present thesis was conducted under Polymer Simulation LTD., a spin-off company of the Laboratory of Polymer Reaction Engineering (LPRE) of Aristotle University of Thessaloniki. Development of process simulation software for the polymer industry. As part of the general efforts to redesign the existing source code database.
- 3. Contents CAD Polymerization Reactor Packages Object Oriented Design CAPE-OPEN Standards Application in MMA Polymerization Conclusions Suggestions
- 4. CAD Polymerization Reactor Packages LPRE software can be used for: Computer Aided Design Computer Aided Process Monitoring Computer Aided Process Control and Optimization Modeling abilities of the software tools: Chemical Kinetics (Monte Carlo Simulations) Polymerization Reactors Other Unit Operations
- 5. CAD Polymerization Reactor Packages The software can be used in a wide range of industrial applications: Analysis of the effect of key process variables on productivity and product quality. Examination of process alternatives for economic optimization and to improve quality. Conducting of safety analysis for reactor runaway conditions. Training of operators to handle process transitions and equipment failure.
- 6. CAD Polymerization Reactor Packages As the polymer industry becomes more global, manufacturers are searching for more reliable software tools that will enable them to achieve competitive advantage. Better collaboration between software developers. Development of web applications for online simulations. Object-Oriented Design CAPE-OPEN Standards Design of Software Packages
- 7. Object Oriented Design Object Oriented Design decomposes a complex system into simple logical objects that are easier to understand, code, and maintain. The major characteristic of Object Oriented Design is encapsulation: Grouping variables and computational methods into logical objects. The logical objects are defined according to real world objects (e.g. chemistry, materials, properties). Simulation of Polymerization Reactor Chemical Kinetics Diffusion Phenomena Physical & Thermodynamic Properties Fluid Flow Energy Balances Complex System Simpler Systems
- 8. Object Oriented Design Example of multi-scale description of a polymerization reactor: Kinetic Model Single Particle Model Population Balance Model Macroscopic Multiphase Mixing Model With Object Oriented Design the various phenomena occurring in micro-, meso- and macro- scales are encapsulated into different logical units which are connected through well defined interfaces.
- 9. Object Oriented Design Chemistry Modeling Tool Specification of kinetic parameters or retrieval from a database Computation of kinetic rate constants Computation of reaction rates (p, T) Computation of heat of reaction Equipment Models Reactor Heat Exchanger Distillation Columns, etc. A general Equipment Model
- 10. CAPE-OPEN Standards The standards of CAPE-OPEN define rules and interfaces that allow chemical process simulators to interoperate. The standards are provided by the CAPE-OPEN Laboratories Network (CO-LaN). Open source codes implementing globally accepted interfaces that are completely transparent allowing the user to tailor the code to his needs. Flow sheet Equipment Models (e.g.: Reactor, Distillation, etc.)
- 11. CAPE-OPEN Standards How does CAPE-OPEN works? Equipment Model External Equipment Models Internal Layer (Fortran) Wrapper (C#) A wrapper is an interface that connects the internal layer of an equipment model (EM) with other EM’s. Equipment Model 1 Equipment Model 2 W r a p p e r
- 12. Application in MMA Polymerization Refactor a Fortran source code for the simulation of methyl methacrylate (MMA) polymerization reactor in order to meet CAPE-OPEN Standards. Description of the chemical process: Type of reactor: Batch stirred tank reactor Polymerization technique: Suspension polymerization Thermal decomposition of initiator Type of control system: Cascade control system (temperature control)
- 13. Application in MMA Polymerization Stages of the diploma thesis: Analyze the code into logical objects (classes). Numerical solutions of the mathematical model using Runge- Kutta 4th and multistep finite differences (Adams-Moulton). Development of a wrapper in order to be able to connect to external equipment models.
- 14. Application in MMA Polymerization Equipment Model Algorithm Flowchart The wrapper is used to pass input data to the equipment model (EM). Using the input data the EM calls the numerical library in order to solve the mathematical models. Results are passed back to the wrapper. If the wrapper is connected with another EM then the results will be used as input data to that EM. Main Program User Input Numerical Method Energy Ballance Mass Ballance Polymer Properties Results Reactans Product By-products Wrapper Reactor External EM Control System t = tinitial,...,tfinal External EM
- 15. Conclusions Minimization of code redundancies. Large software projects become smaller in size. Better code maintenance (fixing bugs, extensions). Pure object oriented codes are computationally slower. Integration with any software that is created using the CAPE-OPEN Standards.
- 16. Suggestions The CPU-intensive numerical computations must be implemented using: Highly tuned FORTRAN or C codes. Parallelization techniques. C++ with template metaprogramming. However, the top level interfaces of the code can still be constructed to provide the typical flexibility of Object Oriented Design. Benefits: Optimal compromise between the flexibility of object oriented paradigm and the speed of the procedural paradigm.