Research On Evaluation Method Of Fan State Of Thermal Power Plant Based On Spectrum And Fault Tree Analysis

There are boiler auxiliary equipment in many thermal power plants. Once a device fails, it could make the whole boiler plant reduced output even paralyzed, bring huge economic losses to the thermal power plant. Induced draft fan as one of the major thermal power plant boiler auxiliary equipment, the quality of the operation is directly related to the long-term stable operation of the boilers. Therefore, it will help secure and stable operation of the boiler to overcome and resolve the induced draft fan failure in order to improve power generation efficiency of thermal power plants. Under normal circumstances, boiler auxiliary equipment in many thermal power plants such as induced draft fans will have a series of signs before failure. This Thesis attempts to establish the induced draft fan status evaluation system, before thermal power plants’induced draft fans breakdown, it will predict whether they make faults by its features in order to determine whether they should downtime and be overhauled. The work in this paper is as follows:We select each spectrum band’s vibration intensity value as vibration state evaluation of the induced draft fan. The typical and important components features in fans which include appearance, operating years, operating environment, the average life expectancy, defect recording, load, fault history and chromatographic oil embody the health status parameters as the induced draft fan status evaluation. What’s more, based on spectrum analysis, we combine and correct the health index by the method of the fault tree status evaluation to set up a fault tree state evaluation model in thermal power plants. The main contents of this paper are as follows:(1) Describes the research status of rotating machinery State evaluation and condition-based maintenance of domestic and foreign state, after making a systematic study to Simple vibration problems, summarizing and analyzing the induced draft fans of thermal power plants typical faults and performance characteristics.(2) Summarizes the detection, extraction and analysis methods of vibration signals of thermal power plants Induced draft fan equipment. And summarizes the selection, arrangement and precautions to the common sensors, gives the measurement method of amplitude, phase, and access to vibration characteristic quantities.(3) Sets up a fault tree state evaluation model in thermal power plants based on spectrum analysis. It includes the selection status evaluation, the concept of health indicators, the set of spectrum bands, and the band vibration intensity calculation and we establish health index calculation process and the relationship between the state deduction and the evaluation of an induced draft fan’ s components to evaluate the induced draft fan’ s running status.(4) By an engineering example to validate the feasibility of the evaluation method, and through this evaluation method to assess an induced draft fan running status in a thermal power plant. And the results show that the method is consistent with the actual situation, therefore the evaluation method is feasible.