Ontology Based Modelling Of Chemical Enterprises

Chemical industry has always been an important part in national economy.In the domain of chemical industry,modeling and simulation play a significant role.Traditional modeling methods often rely on specific simulation environment,which makes it hard to reuse in practice,ontology based modelling theory alleviates this problem to some extent.Domain ontology,model ontology,and ontology mapping method represent the key ingredients of ontology modeling framework.Domain knowledge is contained in domain ontology,model ontology is adopted to design concept model and ontology mapping is used to link domain ontology and model ontology.Model obtained using the aforementioned structure is independent of any given simulation environment,which means higher reusability.However,the ontology mapping method in traditional ontology mapping relies on query,more advanced ontology mapping which is easy to be reused and extended is required.In the meantime,while making simulation on production process,chemical enterprises also propose a new requirement on energy-flow extension that urges us to redefine the ontology modeling framework.In this thesis,ontology mapping method is improved and an integrated ontology modeling framework of material flow and energy flow is proposed.Firstly,poor reusability and scalability associated with traditional modeling methods in chemical enterprises are described and ontology modeling method is introduced.While discussing the superiority of ontology modeling framework,deficiencies of ontology mapping method in current framework are mended.Heuristic rules are extracted based on the characteristic of ontology language and the logic of ontology semantics.The lexical-based similarity matching algorithm quantifies the way by which similarity is calculated.Then the heuristic rules obtained are introduced to the ontology modeling in production process and the domain ontology is mapped to the model ontology automatically.The correctness of the method is verified through a refinery simulation case.Secondly,the need for chemical companies to monitor the energy consumption while ensuring normal production is discussed,then the ontology modeling framework is extended further.Two expansion scenarios are designed respectively depend on whether the total energy consumption or production and consumption of energy medium is counted according to material nodes.For the former case,side line associated with energy consumption of the production unit is designed,while the energy consumption is counted along with the production process.For the latter case,energy-flow system is introduced,material and energy production and consumption model is designed based on the ontology ion of the energy system.Then,the domain ontology and model ontology are extended separately.The concept and structure of domain ontology are extended from the ontological and semantic point of view.The energy flow process and coupling relationship are abstracted and summarized to express the abstraction of the energy flow system.As for the model ontology,the energy-flow system is expanded and energy consumption model is integrated simultaneously,which makes the expanded model has novel ability of energy accounting compared with conventional model.Then,the ontology model based on production process and stem power system of refinery is instantiated.By adopting ontology mapping and ontology translation methods,monitoring system of energy consumption and energy production and consumption report of the refinery process are established.By analyzing the result of energy consumption,several scheduling suggestions are proposed.Finally,the work of this paper is summarized,and the prospects and the potential research directions of this research field are also provided.