吸引压送罐车降噪研究

【作者】 阳东方；

【导师】 李守成；

【作者基本信息】 南京理工大学 ， 车辆工程， 2008， 硕士

【摘要】 本论文针对国内某冶金企业吸引压送罐车工作时噪声污染严重的问题进行了降噪研究。由于罐车工作时其主要部件——罗茨真空泵采用了逆流冷却装置,因此带来了巨大的噪声。为了解决该工程问题,本论文的技术路线是:辨识声源——采取措施——降噪评价。论文首先分析了罐车及罗茨真空泵的工作原理,在理论上确定了罐车可能存在的主要噪声源。重点分析了罗茨真空泵的冷却过程,指出该过程会产生强烈的喷注噪声。在此基础上,通过声强测量得出罗茨真空泵是罐车主要噪声源:通过频谱分析确定了主要噪声源以中低频为主,并在80Hz、120Hz和200Hz处出现较大的峰值。论文针对罐车的主要噪声设计了抗性消声器,并运用声学分析软件SYSNOISE对消声器内部声场进行有限元仿真,计算了其传递损失以预测消声器的声学性能。最后,论文对比了罐车在原装、设计后未减振、设计后减振三种不同消声器下的现场噪声,对降噪效果进行了评价。结果表明,设计后减振的消声器降噪效果比较明显,使工人操作工位处噪声达到国家标准;另一方面也表明,减振对罐车的降噪有至关重要的作用。更多还原

【Abstract】 In this dissertation,research has been done on lowering noise of the suction-pressurization tank car, which is used in smelting plants and makes serious noise pollution. The Roots vacuum pump,which is the main working parts of the tank car,brings high noise because of the countercurrent used for cooling. To solve this actual engineeringproblem,the technology way is,noise sources identification------lowering noise------effectevaluation.At first,the mechanism of the tank car and the Roots vacuum pump was studied in order to get a general understanding of the main noise sources.The cooling process of the pump was elaborated on emphases and it turned out that intense jet noise would happen.Sound intensity that measured around the tank car indicated that the noise from Roots vacuum pump was the main noise source. Frequency analysis showed that the noise was consist of aero noise at the medium and low frequency,with 80Hz,120Hz and 200Hz as its main frequency.A resistance muffler was designed in order to lowering the main noise that has been identified before. To predict the acoustics performance of the muffler,numerical simulation was taken by acoustic software SYSNOISE,in which the interior sound field of the muffler was simulated by finite element method and the transmission loss was calculated.Effect evaluation was done by contrast between the noise data that tested with three different mufflers(which were, the original muffler, the muffler without reducing vibration,the vibration reduced muffler)assembled on the tank car.The result turned out that the solutions were very effective.It also indicated that reducing vibration of the muffler is very important when lowering noise.更多还原