| Large cooling tower fan is the key equipment for the petroleum, chemical, electric power, and other industries in the circulating water system. The role is to generate an air stream in the cooling tower, so the sprayed hot water circulation of the cooling tower can contact with the cold air directly. The heat was Emitted to the atmosphere through evaporation and convection to achieve the aim of being forced cooling and being circularly used of water.The main content of the research is the analysis and study of the cooling tower fan key operating parts failure mechanism. For the failure of blader, driving shaft and gear box which may cause serious accident, the project proposed a monitoring method which is suitable to cooling tower fan. The project took Sinopec Tianjin Branch’s cooling tower fan as research object and designed large cooling tower fan remote monitoring system based on PLC and invert technology and the system was applied in production practice.The research of this project includes:(1) Making a deep research on the structural characteristics of the cooling togrwer fan and carrying out a detailed analysis and study of the failure mechanism for the key parts of the cooling tower fan and accurately analyzing the reason of failure through cooling tower fan failure analysis and combination of theoretical research on the industrial spot.(2) proposing failure monitoring method-blade interval monitoring method,1/4 shaft monitoring method, the oil temperature oil level monitoring method and motor current monitoring method, based on the research of the analysis at home and abroad on the fan failure monitoring methods, and according to failure mechanism of cooling tower fan blades, drive shaft, gear box and motor.(3) Using PLC as cooling tower fan remote monitoring system of control unite and utilizing industrial Ethernet and RS485 communication to realize the communication of on-spot control layer and the upper computer. The system data is uploaded to the factory’s real-time database server via Industrial Ethernet and accesses with C/S or B/S mode.(4) Carrying out realtime On-line monitoring through the inverter technology, measuring fan efficiency and finding out higher efficiency points according to air volume and air pressure at various rotating speed, changing continuous control of motor rotating speed into discrete step-type control, making cooling tower dan at the best working area as far as possible during actual frequency control and realizing the greatest level of energy control. |
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