Research And Design Of Monitoring And Diagnosis System For Main Power Plants In Marine Salvage Vessel

As our country continues ceaselessly attaches importance to the marine salvage business, building a modern has become more urgent. For the main power equipment of marine salvage vessel, with the increasingly high degree of large, complex and automation, while improving work performance, but simultaneously, the possibility of equipment fault increases, and fault types are more complex and diversity. The condition monitoring and faults diagnosis making use of advanced science and technology is an important guarantee for the marine salvage vessel running in good condition. Under the background of "Development of monitoring and diagnosis system for main power equipments in 8000 kW marine salvage vessel" project, this paper, taking advantage of virtual instrument technology and taking LabVIEW software as the development platform, according to the system requirements analysis and functional requirements, synthetically applies thermodynamic parameters monitoring method, instantaneous speed monitoring method, and vibration monitoring method to realizing condition monitoring and fault diagnosis for two main propulsion diesel engines and two diesel generators in engine room. The main research of this paper includes:(1) Taking 6L16/24 diesel engine as the research object, by simulation calculation and analysis of instantaneous speed, verify that diagnosing cylinder combustion status by instantaneous speed is practicable. Measure instantaneous speed signal in different conditions of normal-state and fault-state. By observing instantaneous speed waveform figure and spectrum diagram, raise clearly an diagnosis rule based on volatility peak and amplitude ratio of harmonic wave in frequency spectrum, to provide the theoretical and testing basis.(2) Analyze the monitoring and diagnosis system as a whole, including monitoring objects, monitoring and diagnosis requirements analysis, system functional requirements and system overall structure. The system adopts different data acquisition techniques, a variety of monitoring and diagnosis methods, data transmission technology and database management technology, to achieve synchronizing real-time condition monitoring, fault alarm and diagnosis for multiple devices.(3) The system software, tightly around the users' needs and functional requirements, according to the design flow of interface design first and then program structure design, adopts the mode of combining "taking data flow as the main line" and "object-oriented ideas" for modular design.(4) According to engineers' user-needs and usual practices, make use of the display controls in accordance with professional standards to design the user interface, which is user-friendly, soft colors, eye-catching visible alarm zone, with freely switching between either interfaces.(5) As the core of the entire software, main program has a good solution to implement interface switching freely, multi-threaded processing, data acquisition and transmission, subroutine calling and other key issues, not only to ensure the realization of system functions, but also to avoid high system resources utilization rate and memory overflow, in order to make the program run in highly efficient.(6) The system makes use of access database technology, and adopts structured data management mode to classify the types of monitoring data, with the procedures which adopts effective data storage mechanism to achieve automatic storage for all types of monitoring data, and implement database files management.(7) According to the system functional requirements and site conditions, in accordance with the basic technology of marine hardware devices requirements, make system hardware selection and field installation, integrate the system software and hardware, and take site debugging for the whole system. After system running normally, analyze the instantaneous speed and its feature of the monitoring plants, to verify the system monitoring function.