Study Of Preventive Maintenance Policy For Small And Medium Sized Rotating Machine In Petrochemical Industries

Petrochemical industries belong to one of the high-risk industries,and most of the materials involved are inflammable and explosive chemicals.Although the rotating machine has been inspected and meets the strict standard requirements,due to the abnormal working state,the failure of other devices and some unforeseen circumstances,it may trigger the deterioration of components,and finally resulting in equipment failure.The accident in chemical industries due to the fault of rotating machine is often very serious,causing great damage to the environment and property,also causing a large number of casualties.So maintenance is necessary to maintain the reliability and availability of the rotating machine.The mechanical fault diagnosis method is very effective for large rotating equipment,and is also suitable for the abnormal signal detection of small and medium rotating equipment.However,it is difficult to monitor all of it because of the variety and the large number of small and medium equipment.Compared with condition based monitoring,reliability prediction is more suitable for long period maintenance of small and medium sized rotating equipment.Traditionally,the inspection and maintenance strategies of rotating machine are determined by empirical and qualitative methods,lacking systematic research on the maintenance policy.The study of preventive maintenance policy including the failure analysis,determining maintenance strategies,the threshold parameters,maintenance intervals and its implementation.In this paper,the failure analysis of the typical rotating equipment is carried out firstly,and different maintenance strategies are implemented by analyzing different components' failure characteristics through the recorded maintenance data.The pressure,load and the bad working conditions would affect the useful life of the equipment.Main factors that affect the failure time of the vulnerable parts are analyzed and the proportional hazad model is established.Secondly,different prediction models are compared according to the failure process of the equipment and proposed a three-stage degradation model for important component,the internal degradation process,external impact and maintenance effect are taken into consideration while modeling the reliability of these components.The parameters of the prediction model are estimated through the detection data and the failure data,and the practicability and effectiveness of the model are analyzed through an example.According to the proposed maintenance strategy of the degradation model,the cost optimization model is built to determine and optimize the important parameters in the maintenance strategy,the reliability of the components under the preventive maintenance strategy is also calculated.Finally,this paper expounds the data collection and organization management structure in the implementation of the preventive maintenance policy,and established the maintenance performance metrics.