| Mine FBD counterrotating axial flow fan is a new type of local fan,which has the characteristics of compact structure,large air volume and high wind pressure,and is widely used in coal production enterprises.However,when the fan is running,it will produce large radiation noise,and the narrow section space of the tunneling roadway will lead to further amplification of noise harm and seriously affect the physical and mental health of operators.Therefore,it is of great significance to carry out the research on the noise control technology of the rotary axial flow fan for mining FBD.This paper takes mine FBDNo7.0/2 × 45 axial flow fan as the research object,adopts the methods of theoretical analysis,numerical simulation and experimental demonstration to study the noise control from sound source and propagation path respectively.The main work contents are as follows:(1)The noise spectrum characteristics of FBDNo7.0/2 × 45 axial flow fan were measured and analyzed.The results show that the noise frequency characteristics of the fan are in the shape of broad frequency,and the middle and high frequency are prominent,which lays a foundation for the future direction of noise control.(2)3D model of the fan was established.Based on Fluent,the influences of relative axial spacing and blade perforation on eddy current noise were investigated respectively.The optimal axial spacing was obtained as 1.1,and the feasibility of blade perforation noise reduction was verified.(3)Based on LMS Virtual.Lab software,the acoustic simulation analysis is carried out.The results show that the average insertion loss of the sound absorber is about 3.5dB at the same measuring point,and the average insertion loss of the new noise reduction core is about 4.3dB.(4)Four kinds of inlet and outlet resistive mufflers were designed,and the numerical simulation was carried out to explore the influence of different structures,materials,perforated plate and muffler length on transmission loss.Meanwhile,the muffler structure was optimized to reduce pressure loss and ensure the operation efficiency of the fan.(5)According to the above conclusions,the noise spectrum characteristics of fBDNo7.0/2 × 45 axial flow fan were measured again,and the results show that the noise value meets the specification requirements,which verifies the feasibility of the overall scheme.Fig..47 Table 9 Reference 57... |
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