【作者】 王艳；

【导师】 王和慧；

【作者基本信息】 华东理工大学 ， 固体力学， 2014， 硕士

【摘要】 本文针对安顺电厂300MW“W”型火焰锅炉炉墙大幅振动问题,从燃烧负压波动和声腔共振两方面展开机理研究。首先采用数值仿真方法对锅炉炉内燃烧进行实际工况计算。通过分析炉内温度场、压力场、速度场以及过量空气系数分布,发现燃烧中心偏高,配风比需调整,针对发现的不足提出增大乏气进气速度等的合理性建议。其次利用ANSYS和Virtual.Lab软件采用模态分析方法,分析了炉墙结构模态、炉腔声学模态和结构-声耦合模态,分析了发生声腔共振的可能性,发现10HZ频率内前墙不会发生声腔共振。然后针对实际晃动的大幅低频特性(10HZ内),通过在前墙刚性梁上加止晃装置的方法进行模态改进,综合考虑经济性和最终达到的效果,可知第四种布置方式最优。布点方式成#型,与刚性梁由绕带式向栅格式的发展趋势不谋而合。最后分析了炉墙在谐激励下的受迫振动响应和产生的噪声。燃烧模拟对锅炉燃烧参数的调整有一定指导作用,并为止晃设计提供压力载荷数据。现有锅炉振动研究中几乎没有定量考虑声—固耦合的影响,故声固分析对锅炉声腔共振的防治设计具有参考价值。振动噪声分析对预防噪声污染具有参考意义。更多还原

【Abstract】 The article studies on two aspects, pressure fluctuation and vibro-acoustic resonance, in Anshun W-shaped boiler furnace wall vibration case.Firstly, use Fluent software to calculate boiler furnace combustion with numerical simulation method under working conditions. Temperature, pressure, velocity and air coefficient distribution are studied, the real condition of pulverized coal combustion are obtained, and which is valuable to optimize the imported conditions. Secondly, use ANSYS and Virtual Lab software with modal analysis method to analyze the furnace wall structure modal, furnace acoustic modal and structure-acoustic coupling modal. Whether the resonance is occurred can be obtained. Thirdly, while the actual vibration is with high amplitude in low frequency significantly (below10HZ), to add point constraints in rigid beam of the front wall to optimize front wall modal, the fourth arrangement is better considering the economy. The arrangement shaped#agrees with the development tendency of rigid beamFinally, the vibration and noise under harmonic excitation are studied.Combustion simulation is valuable to adjust the boiler combustion parameters, the quantitative data in vibro-acoustic resonance are lacked in the existing references on boiler vibration, so the result can provide valuable reference to vibro-acoustic resonance and safe design. The result of vibration and noise is of great value to control noise pollution.更多还原