| In China there are a large number of fan equipment used in the entire thermal power unit,the fan is the fuel generated after the combustion of flue gas from the boiler out,and into the atmosphere.The main transport of ash,fly ash and tar containing the state of the fractions of flue gas,and the higher temperature,relative to other fans of its working environment is more complex,fan operation is also different from the conventional fan,so for long-term high temperature Flue gas environment,the influence of flue gas temperature on the performance parameters of the fan is analyzed,and the law of the operating characteristics of the draft fan under high temperature environment is grasped,which has high practical significance and engineering value.In this paper,the AP single-stage adjustable blade axial fan is used as a research object of a 2 × 600 MW coal-fired power plant.The numerical simulation is carried out by using the computational fluid mechanics method to simulate the different flue gas temperature The characteristics of the fan operating characteristics,the aerodynamic noise and the blade wear are analyzed,and then the characteristics of the induced draft fan in the high temperature flue gas environment are analyzed.Finally,for the high temperature flue gas environment,the leaf clearance with large influence on the performance of the draft fan is discussed,The performance and mechanism of the gap lower fan.Get the following conclusions:(1)The numerical simulation of the flow field distribution of the induced draft fan under different inlet flue gas temperature can be found.With the increase of flue gas temperature,the total pressure of the draft fan is obviously reduced and the energy loss of the induced draft fan is increased and the working efficiency The flow rate of the flue gas is gradually increased,and the flow field between the adjacent leaves increases with each other.The change of the flue gas temperature,the change of the flue gas temperature,the change of the flue gas temperature,the change of the flue gas temperature,The noise of the induced fan does not have obvious influence,but with the increase of the flue gas temperature,the noise mainly is mainly whirlpool noise,and the noise source gradually moves to the top of the blade.(2)On the basis of the previous simulation,the solid particle model was added to analyze the blade wear of the draft fan in the high temperature flue gas environment,and it was concluded that the blade wear was becoming more and more serious as the flue gas temperature increased The wear of the blade is mainly concentrated in the lower half of the blade pressure surface near the leaf,and the most serious area appears at the leading edge of the middle of the blade pressure surface.(3)According to the high temperature flue gas environment of the actual operation of the draft fan,the leaf tip clearance with large influence on the performance parameters of the draft fan is simulated and analyzed.Under the high temperature flue gas environment,the gap of the blade is increased and the total pressure of the draft fan is reduced,The efficiency of the blade is also decreased.The leakage of the blade is enhanced and the leakage vortex is formed.The vortex is gradually moved on the blade front and the pressure surface.The noise of the induced draft fan is increasing and the blade wear is serious.Through the above analysis and research,the operation characteristics and characteristics of the axial runner of the power plant under the high temperature flue gas environment are obtained comprehensively,which provides a basis for the reconstruction of the fan and the theoretical research. |
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