L.F. Acebes

Sugar Crystallization Benchmark

Abstract The design of scalable and efficient plant-wide optimal control and operation schemes in process industries is an important research topic. Most promising strategies approach the problem by subdividing overall large optimization problems into local, more manageable tasks. The solutions for sub-tasks need to collaborate with each other in driving the process near the optimal operation of the overall plant. This paper describes a benchmark model of the evaporation and crystallization sections of a beet sugar factory that provides a test-bed for this kind of approach.

Knowledge based diagnosis: dealing with fault modes and temporal constraints

An expert system performing tasks of supervisory control and fault detection and diagnosis was developed for a beet-sugar factory. Even when it can manage most usual alarm situations, the diagnosis method can not be easily extended to manage problems requiring a more complex analysis, such as phenomena involving nontrivial time evolution or multiple fault diagnosis. This is mainly due to two facts: the rule based approach to the diagnosis and the simplified treatment of some temporal aspects. A diagnosis strategy based on fault modes, including temporal knowledge, is now proposed. The paper describes the outstanding ideas supporting the design, some comments about the system architecture, simulation results over a real plant, conclusions, and further research.<<ETX>>

SUGAR FACTORY SIMULATOR FOR OPERATORS TRAINING

Abstract This paper presents the main features of a sugar factory training simulator currently used for control room operators training. This simulator is based on a realistic distributed real time simulation of the whole factory and in a mimic of the control system. It allows the familiarization of the operators with the process and control system as well as with the process information that they use in the real plant. The main aims of the simulator are: (i) to guarantee operators knowledge of the process, and its control system; (ii) to test potentially dangerous situations and (iii) to identify possible problems sources and learn to correct them.

MODELLING AND SIMULATION OF BATCH PROCESSES: A CASE STUDY

Abstract Modelling and simulation are inseparable procedures that include the complex activities associated with the construction of models representing real processes, and experimentation with the models to obtain data on the behaviour of the system being modelled. This paper shows how an objected-oriented modelling language can be used to build the dynamic simulation model of an industrial production process that contains both continuous and bath units. The selected case of study is an essential part of a sugar factory: the sugarhouse.

Educational Simulators for Industrial Process Control

The paper shows a Windows© NT/XP/7 application oriented to learn control skills to process engineers. It is a dynamic simulation based tool with a friendly user interface that contains two sets of diverse process control problems (more than twenty study cases are available). It is possible to study typical control problems as cascade, ratio, selective, override and feedforward control techniques and the tuning, configuration and operation of PID controllers. Additionally, it allows analyzing complex control systems installed in boilers, furnaces, distillation columns or reactors and special industrial control techniques to ensure the process safety. In order to outline the functional features of the tool, one of the simplest modules is shown. To conclude, an overview of the methodology and software used to develop this tool is also outlined. In particular, an object oriented modeling and simulation tool is used to develop the simulation models, a self-developed SCADA is used as graphical user interface and the simulation-SCADA communications are supported by the OPC standard. Finally, it must be remarked that this tool is used successfully in an industrial master of instrumentation and process control.

Modelado y Simulación del Proceso de Producción del Azúcar

In this paper a methodology for the development of dynamical mathematical model libraries for the sugar industry is shown. The library specifications and requirements make necessary the use of the Equations Based Object Oriented Modelling paradigm. Using a tool that complies with that paradigm a set of model libraries, containing the necessary components for building a complete sugar factory, have been developed. In this paper the most interesting constructive details of the sugar process libraries and some of the faced problems during its development are shown. The construction of the whole sugar factory is possible by connecting the different developed components by mean of the aggregation mechanisms provided by the used tool. The main contribution of the developed library, compared with other commercialized libraries, is the use of dynamic detailed models including malfunctions and anomalies. This feature provides a great versatility when using the library in applications like controllers design, training simulators or when the model is used as a source of data in online optimization process tools.

Librería de Modelos Orientada a Objetos para la Simulación del Cuarto de Azúcar: Cristalizador Continuo por Evaporación al Vacío

EEl Cuarto de Azucar constituye el ultimo departamento importante de una fabrica de azucar de remolacha. Recibe de las secciones anteriores de la fabrica un jarabe concentrado de sacarosa y entrega el azucar blanco cristalizado de valor comercial. En este articulo se describen las caracteristicas generales de una libreria Orientada a Objetos para modelar Cuarto de Azucar tipicos con el objetivo de crear herramientas de simulacion para entrenamiento de operarios y se describe de forma detallada el modelo dinamico del cristalizador continuo por evaporacion al vacio.

Rule Based Approach to First Principles Modelling in the Sugar Industry

Abstract This paper introduces the main characteristics of a modelling language, SIMPD, oriented to facilitate the use of dynamic simulations of processes in the sugar industry. The tool is based in expert knowledge and organized around two main libraries: one of classes describing elementary process units and other of rules for model generation. The paper describes the architecture and internal mechanisms that allow to generate simulation code based on first principles models from process descriptions given by schematics.

Modeling and simulation of a beet pulp dryer for a training simulator

ABSTRACT This paper deals with the modeling of a high-temperature rotatory sugar beet pulp dryer for training simulators. This model adds some aspects to traditional drum dryer models; particle size distribution, detailed modeling of the solid phase, and the inclusion of malfunctions in the model. An object-oriented simulation package is selected to implement this model in a library, together with models of other components of a drying plant. Using this library, the complete plant and its control system are built and simulated. Finally, the simulation of the plant integrated together with a SCADA makes up the training simulator.

Análisis en Linea del Estado Energético de Plantas Azucareras

This paper describes a software system for the energy diagnosis of sugar factories that has been developed in the Center of Sugar Technology (CTA). This tool takes data from the real process and uses a stationary model (based in energy and mass balances), data reconciliation algorithms and optimization techniques to calculate non measured variables, eliminate errors in measured variables and obtain index of the energy efficiency. This software must be implemented in different factories in Spain. So a set of tools has been developed to allow a fast configuration and code reuse. In particular, a library of stationary, modular and configurable models of sugar process units has been implemented in an Equation Based Object Oriented Modelling Tool and an adaptable SCADA with specific requirements has been developed.