Study On Safety Evaluation Expert System Of Submersible Electric Pump Based On Fault Tree Analysis

The production cost of SEP was rised and the economy benefit was reduced, because of the shorter checking period, more frequent workovers and more expensive equipments. So it is necessary to make software of safety evaluation expert system of SEP system, which can figure out the faults earlier, take preventive measures, reduce the economy lost.This thesis mainly discusses the design and implementation of the safety evaluatioin expert system of submersible electric pump, fault tree analysis and probability calculation. First, it introduces the meaning and background of developing this system and summarizes the knowledge of safety evaluation and expert system. Then analyze the principle of SEP system, find out the primary reason of the faults through local investigation and draw fault trees separately, calculate the structural importance by using Boolean algebra, make software of fault tree analysis and probability calculation. The safety evaluation expert system of SEP system is composed of knowledgebase, inference engine, character database, man-machine interface, explanatory program etc. Experience knowledge is expressed with production rules from the knowledgebase. Accuracy consequence is imported in the method of safety evaluation expert system, and combining with the analysis method of fault tree that the probabilities of the rules are confirmed. Accordingly changed the field expert knowledge to expert system experience knowledge, and confirmed the method of inference.The forward and backward inference is used in the inference engine. According to initial data that user put into database and knowledgebase, inference engine make proper result with forward chaining. And then the main functions are realized by using Visual Basic, At last, this thesis impersonally and generally evaluates the system, and gives proposal for improvement.