Ontology Modeling And Its Application In The Diagnosing Energy Use Of Central Air Conditioning System

With economy goes up stably, the number of large public buildings is gradually increasing. The energy consumption of the existing public building stays high in China, while central air conditioning systems play a critical role in the existing public building. Diagnosing the energy use of central air conditioning will be helpful not only to remove potential fault, but also to reduce energy waste in the public building. So, it is worthwhile for China’s energy conservation and emission reduction to diagnose central air conditioning system.In diagnose process, this method needs to be changed and adjusted to adapt to different requirements of different program. This thesis designed ontology to describe the knowledge and experience in air conditioning area. With the help of ontology, the knowledge in central air conditioning can be achieved on the level of domain knowledge representation. Based on ontology, the information retrieve and inference can be executed to draw diagnosis conclusions. And ontology can help to share the knowledge of air conditioning system between different programs. The information isolated island will be eliminated because of the applications of ontology, such as information retrieve and inference.This thesis includes two parts.Firstly, the ontology model of air conditioning system is constructed. (1)Depending on the demands of the central air conditioning system, this thesis applied the SEVEN STEP method to build the DIAGNOSE ontology for the diagnostic process of central air conditioning energy use. In the DIAGNOSE ontology, common abnormalities are described by "phenomenon"+"component" in the owl files. Each abnormalities respectively have the abnormal causes, and the corresponding solutions. The relationship between abnormality, abnormal cause and the corresponding solution can be defined by using classes and properties in owl files. (2)The SSN ontology is reused and extended by SENSOR ontology.Secondly, The ontologies in knowledge base will be retrieved and inferred to diagnose the central air conditioning system. In order to test the feasibility and applicability of this method, a test system is established. At the last chapter, this thesis build a database table structure for this test system. Also, an OPC client is designed to retrieve data from the operating database. In addition, a D2RQ platform is designed to convert the relational database to RDF data format conversion. and a Jena API is called to develop semantic web applications.