Ship Engine For Health Management Digital Modeling And Simulation Study

The health management for dual-fuel engines is in the initial development stage,and for such a complex system as marine dual-fuel engines,its geometric structure and assembly contain a large amount of data,plus the load,environment,maintenance and other data generated during operation,which leads to the existing PHM technology cannot achieve accurate and rapid centralized processing and analysis in the face of the rapid and massive dynamic evolution data generated by dual-fuel engines Therefore,the digital modeling-driven PHM model has become a research hotspot in the field of marine dual-fuel engines,which has a great impact on the performance and reliability of the system.The main work of the thesis,which focuses on marine dual-fuel engines,includes four aspects:(1)To address the problems of multi-element coupling of dual-fuel engines,monitoring and extraction of signals in the case of low sex-to-noise ratio,the dual-fuel engine health management system architecture is constructed to evaluate the health status of the multi-element coupled engine system,while the health assessment level is established on the basis of optimized health factors.An abnormal state prediction model based on the improved TCN algorithm is established,while the DRSN algorithm is improved and a fault diagnosis model based on the improved DRSN algorithm is established.After example verification,the two improved models,IMP-TCN model and IMP-DRSN model,have better performance than the traditional models,indicating that the models can be better applied to the abnormal state prediction and fault diagnosis of engines.(2)To address the problems of cumbersome modeling of dual-fuel engines and the need for large amounts of data support,the study of the structure,operation mode,main systems and relevant technical parameters of a model dual-fuel engine of the DF series of the digital subject CSC Power,the establishment of a digital modeling process for health management of dual-fuel engines and its characteristics,and finally,based on the structure of dual-fuel engines,the use of thermodynamics,dynamics and other multidisciplinary theories,combined with Finally,based on the structure of the dual-fuel engine,the modular modeling of the main five subsystems of the dual-fuel engine is carried out by using the multidisciplinary theories of thermodynamics and dynamics,combined with lightweight and modular digital modeling methods.(3)To address the problem that the dual-fuel engine model only simulates the normal operation process but lacks the simulation of abnormal and fault processes,we conducted a dynamic simulation study using the built dual-fuel engine digital model,and completed the numerical simulation of cylinder pressure,turbine outlet pressure and exhaust temperature of the dual-fuel engine digital normal model,abnormal model and fault model under different natural gas substitution rates and different load conditions.Finally,the actual engine operation data were imported into the model to verify the accuracy and reliability of the model.(4)To address the problems of few dual-fuel engine health management systems and incomplete functions,a dual-fuel engine health management system based on digital modeling and deep convolutional neural network for marine LNG is designed.faults were studied by example,and the system can effectively identify the types of abnormalities and faults and give intuitive diagnosis results,maintenance suggestions through the visualization interface.