A study into the feasibility of an intelligent knowledge based system (IKBS) in computational fluid mechanics (CFM)

Recently, the emergence of powerful microcomputers has brought comprehensive CFM within the reach of small companies. Consequently, numerical techniques for design and development are becoming cost-effective compared to the increasingly-expensive experimental approach. However, computational fluid modelling of realistic situations is highly complex and requires specialist expertise. The level of complexity is reflected in a leading CFM package, PHOENICS, which is used for the simulation of fluid flow, heat/mass transfer and chemical reaction processes. To successfully apply PHOENICS to a specific problem, specialist knowledge of data input, reasoning adopted by the software, the physics involved and the interpretation of results is essential. This work assesses the feasibility of developing an IKBS to assist and train users with the problem specification process within PHOENICS. An evaluation of a suitable IKBS tool and hardware requirements is included in the assessment.     

CAD for process plants: an update

We review the availability of CAD software for the process design activities of physical properties generation, unit operation design, flowsheeting and dynamic flowsheet simulation. Similarly we look at CAD software for materials control, piping documentation and pipe stressing. We report conclusions drawn from our research into the provision and use of CAD turnkey systems for producing schematics at the conceptual design phase, and for equipment specification, layout, piping design and 3D modelling at the engineering design phase.By reviewing the shortcomings of current CAD systems along with developing CAD technology, we were able to specify the requirements of the next generation of process plant CAD.     

A system for compartmental modelling and simulation

The paper describes a software package for modelling and simulating compartmental systems based upon a generalisation of the equations of compartmental systems. The aim is a versatile package which can be used for rapid model development. Its use is first illustrated in a number of simple classical examples. The power of the software--and more generally the methodology--is demonstrated by showing its application in developing a model-based system for insulin planning for diabetic patients. The software has been written in Pascal and runs on IBM PC and compatible computers.     

IVTANTHERMO for Windows — database on thermodynamic properties and related software

A new version of the software package IVTANTHERMO for Windows intended for thermodynamic modelling of complex chemically reacting systems is described. The package includes an extensive database on thermodynamic properties of individual substances, programs for the database handling and a program, which allows the calculation of equilibrium composition and thermodynamic properties of the system to be examined. The software is intended for scientists, chemical engineers and students.     

面向能力培养的化工仿真实习软件MES

以能力培养为目标,我们编制了化工仿真实习软件ＭＥＳ,在软件中运用现代化的教学手段,如二维、三维运历,视频,音频技术,工业仿真技术等,解决原来化工类专业实习教学中的问题,培养学生的工程实践能力,改善教学效果,该软件以具有代表性的年产３０万吨合成氨装置为蓝本,讲述了化工工艺、设备测控仪表及ＤＣＳ等方面的知识,并备有开测验题库及仿真培训软件部分,该软件系统在我校试用获得了很好的教学效果。     

CIMOSA modelling processes

Engineering, integrating and managing complex enterprises requires the understanding, and the ability to partition and simplify their operational complexity. Enterprise modelling supports these requirements by providing means for describing process oriented systems and decomposing those into manageable pieces. However, enterprise modelling requires both a common modelling language and a sufficient modelling methodology. The language provides for common understanding on enterprise models across the industrial community. Modelling methodologies will guide users through the rather complex enterprise modelling tasks. Depending on the skills and the tasks of the modelling person, different methodologies will be implemented in the supporting modelling tool. The paper presents both a methodology for the modelling expert and one for the business user. Whereas the modelling expert will be involved in creating new models, structuring the model contents and developing new modelling components, the business user will use process models for decision support. The latter therefore has a need to modify and adapt enterprise models to represent operational alternatives. A methodology for this type of work has to be based on menus. Menus which are created and maintained by the modelling expert. The business user will mostly work with existing process models. He will evaluate process alternatives and will implement the best solution as the new model of his tasks. This mode of operation will thereby provide for automatic update of the models and will keep the models in sync with the changing reality.     

以组态软件为平台开发IPC模式过程仿真培训系统

本文根据精细化工生产过程的工艺特点，以自控组态软件为用户图形界面开发平台，采有IPC单台PC机智能控制仿真模式，应用动态补偿法拟合过程的动态数学模型，并用Visual C 编制生成模型仿真计算动态链接库函数，通过组态软件的数据库与仿真图形操作界面相连，开发了一套复杂的小型精细化工生产过程的动态仿真培训系统，该系统经工艺技术人员考核运行和实际培训使用，表明其具有良好的仿真操作培训作用。     

CAMBIO: software for modelling and simulation of bioprocesses

CAMBIO, a software package devoted to bioprocess modelling, which runs on Apollo computers, is described. This software enables bioengineers to easily and interactively design appropriate mathematical models directly from their perception of the process. CAMBIO provides the user with a set of design symbols and mnemonic icons in order to interactively design a functional diagram. This diagram has to exhibit the most relevant components with their related interactions through biological and physico-chemical reactions. Then, CAMBIO automatically generates the dynamical material balance equations of the process in the form of an algebraic-differential system by taking advantage of the knowledge involved in the functional diagram. The model may be used for control design purpose or completed by kinetics expressions with a view to simulation. CAMBIO offers facilities to generate a simulation model (for coding of kinetics, introducing auxiliary variables, etc.). This model is automatically interfaced with a specialized simulation software which allows an immediate visualization of the process dynamical behaviour under various operational conditions (possibly involving feedback control strategies). An example of an application dealing with yeast fermentation is given.     

Modelling of the whole process of a university campus CHP power plant and dynamic performance study

Combined heat and power (CHP) refers to a process/system designed to utilize the waste or residual heat from a power generation process. Thus, a CHP plant can produce both electricity and heat. The nature of such a combination makes the process more complex than any single power generation process or boiler heating system. The paper focuses on modelling study and analysis of energy efficiency of the University of Warwick micro-CHP power plant. In this CHP modelling study, a gas turbine module is built to provide driving power and methane is used as fuel gas. Heat recovery system and auxiliary boiler modules are developed for thermal power generation. All the sub-systems are validated by comparing the simulation results with the operating data collected from the CHP plant. The dynamic performance of the key CHP process outputs is studied with respect to the variation of the input syngas stream, including electricity generation, thermal power output and water output temperature. Simplified controllers are also applied to the gas engineheat recovery subsystem and auxiliary boiler. Simulation results with/without feedback control are both analyzed. The study has highlighted the key factors which influence the plant performance and suggested the strategy for potential energy efficiency improvement.     

Evaluation of techniques for manufacturing process analysis

In the last 20 years, several methodologies, models and tools have been developed for the analysis and optimisation of manufacturing systems in order to propose general improvements. Many of these techniques make extensive use of data modelling, simulation, decision-making support, expert systems and reference models. This paper presents the first outcome of a piece of research work to integrate manufacturing process analysis into an integrated modelling framework covering all aspects related to the shop-floor as it really is. The main methodologies and software tools have been identified and evaluated and the results tested on industrial examples. As a result of this evaluation it has been possible to identify the inefficiencies of the techniques. These problems are connected with integrating the different types of data to be analysed—such as quality, time, costs, resource capacity, productivity, flexibility or improvements—into a single analysis environment. The inefficiencies detected enable us to present a general framework for making better use of modelling techniques for manufacturing process analysis. Received July 2005 / Accepted January 2006     

Neural networks in process life cycle profit modelling

Changes in operational environment of the process industry such as decreasing selling prices, increased competition between companies and new legislation, set requirements for performance and effectiveness of the industrial production lines and processes. For the basis of this study, a life cycle profit (LCP) model of a pulp process was constructed using different kind of process information including chemical consumptions and production levels of material and energy flows in unit processes. However, all the information needed in the creation of relevant LCP model was not directly provided by information systems of the plant. In this study, neural networks was used to model pulp bleaching process and fill out missing information and furthermore to create estimators for the alkaline chemical consumption. A data-based modelling approach was applied using an example, where factors affecting the sodium hydroxide consumption in the bleaching stage were solved. The results showed that raw process data can be refined into new valuable information using computational methods and moreover to improve the accuracy of life cycle profit models.     

A methodology for the automation of medium or small manufacturing companies

Many products are produced by discrete manufacturing plants in lots of 100 items or fewer. Currently, most small and medium-sized manufacturing companies are far from computer-integrated automation. New computer-integrated manufacturing systems with their associated hardwares require tremendous initial investments that are beyond the means of most small and medium-sized companies. In this paper we investigate how these companies can upgrade and automate their existing facilities at a minimal and viable cost. In Section 2 we discuss main references (books and trade journals) that contain detailed information on software packages for automation. In Section 3 we discuss the criteria for selecting software packages. In Section 4 we discuss how to use the obtained information to create a data base of different alternatives. In Section 5 we outline different areas of manufacturing. For illustrations, we discuss manufacturing planning, intelligent systems, and computer areas. In Section 6 we discuss a new method for the selection of the best alternative using the data base. The method is a simple interactive paired comparison method based on a computer package developed on a personal computer.     

Model-based analysis of the health, safety and environment domain in the process industry

The chemical process industry needs well-defined, engineering-controlled operation procedures to insure the safety of their plant operations and to protect the people working with hazardous materials. Accidents may seriously harm the employees, destroy expensive factory equipment and contaminate and deteriorate the environment of the entire areas. The engineering control can be significantly enhanced through the use of process models for situation analysis. Process models will also provide effective decision support in the plant operation. The objective was to develop in Elf-Atochem a reference model for improving the complex process for implementing and tracking a work permit for people working in plant areas with health, safety and environmental risks. This permit documents all protection and formal authorisations required prior to any work in the hazardous areas of a chemical plant. The model consists of a process model and an information model. It further provides the identification of knowledge required to manage the work permit and to facilitate the automation of a number of activities. The model serves to analyse the process and to define the user requirements for a workflow application program. The methodology CimOsa/rg, which is based on CIMOSA, has been applied together with the modelling tool CimTool to document the requirements model.     

工艺流程图CAD软件的设计

工艺流程图是一般流程型工厂设计中很重要的一步,是工艺设计资料中最重要的资料之一,它可以有效地指导后续的配管设计,仪表设计和施工等,本文设计的工艺流程图软件,实现了与流程模拟软件的集成,同时可与配管设计,仪表设计等共享数据,本文对工艺流程图CAD软件的设计进行了结构和功能上的分析,并对软件设计过程中的两个关键技术;图形库和并管操作进行了详细的讨论。     

发电企业竞价上网博弈模型及其算法研究

假设所有发电企业通过密封报价这种形式来上网竞价,并在发电企业共同见证及同一时刻开标,且规定报价最低者将会被选为中标方,设计两个发电企业竞价上网的基于静态贝叶斯理论的博弈模型以及算法,当参与的发电企业均应用线性策略时,对模型所对应的收敛性进行了分析,同时对贝叶斯纳什均衡解是否存在进行了讨论;接下来对两个发电企业竞价上网模型予以相应扩展,分析了若干个发电企业竞价条件下的贝叶斯纳什均衡及相关问题,与此同时,构建了一个包含若干发电企业在内的共同竞价上网博弈模型;最后借助计算机系统予以仿真实验,得到的结论是：在电力竞价上网的博弈模型中,随着企业数量的不断增加,各自报价将会更加理性,并不断趋于预测值。     

Modelling and simulation of flexible manufacturing systems (FMS)

Designs of flexible manufacturing systems (FMS) must be inspected using model experiments based on appropriate simulation software (SS). Problems connected with the development of SS will be discussed. Morover, a special modelling and simulation system suitable for FMS will be presented.