Early Fault Diagnosis And Repair Quality Evaluation Of Centrifugal Pumps

Centrifugal water injection pumps are widely used in oilfield exploitation due to their advantages such as light weight,small volume,large displacement,stable outlet pressure,and long life.However,as the equipment gradually develops in a continuous,integrated,and intelligent direction,how to effectively prevent the occurrence of major failures has become an urgent challenge for equipment managers.The thesis conducts relevant research on the two difficult problems of early failure diagnosis and maintenance quality evaluation in the above challenges.The specific contents are as follows:(1)The failure mode analysis method of centrifugal water injection pump based on FMEA is proposed.Through the FMEA analysis,this paper summarized the common failure modes,failure causes and failure consequences,such as impeller and mouthring failure,balancing device failure,mechanical seal failure,pump shaft failure,bearing temperature failure,rotor axial movement faults and coupling gap faults,etc.,and put forward targeted improvements,laying the foundation for subsequent fault diagnosis and maintenance quality evaluation.(2)An early fault diagnosis method based on spike energy and convolutional neural network(CNN)is proposed.In order to overcome the difficulties that the early fault dynamic response of centrifugal pumps is weak,the impact of noise is serious,and the low signal-to-noise ratio leads to difficult to diagnose problems,the peak energy method is used to filter out low-frequency signals to achieve the enhancement and extraction of early weak fault features.Based on CNN,the features are self-extracted for fault diagnosis,and finally,the feasibility of the proposed method was verified with the test data from oil field.(3)A maintenance quality evaluation method of centrifugal water injection pump based on multi-level fuzzy comprehensive analysis is proposed.In view of the problems that need to be considered from multiple levels and factors in the evaluation of the maintenance quality of centrifugal water injection pumps,a multi-level evaluation index system is constructed from four aspects: equipment material characteristics,component maintenance effects,machine response characteristics,and equipment key performance,and then the comprehensive index system for maintenance quality evaluation are constructed.Finally,a case study of on-site centrifugal water injection pump maintenance was conducted to evaluate and verify the feasibility of the method.(4)A software was designed and developed to diagnose faults and evaluate maintenance quality for centrifugal water injection pumps.Based on the proposed methods of fault diagnosis and maintenance quality evaluation,the paper uses programming languages C# and SQL databases to design and develop a software system suitable for centrifugal water injection pump fault diagnosis and maintenance quality evaluation,which reduces the workload of field personnel and improves the level of equipment management.