斜盘式空调压缩机振动噪声仿真分析与试验研究

发布时间：2018-01-31 05:18

本文关键词： 斜盘式压缩机机械噪声流体噪声约束模态减振降噪台架试验　出处：《吉林大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着我国经济的快速发展,家用轿车走进了千家万户,人们对汽车的要求也越来越高,可以改善车内乘坐条件的空调系统已经成为人们购选汽车时必不可少的一部分。但汽车空调压缩机作为空调系统中最主要的部分,同时也引入了另一个不可忽视的问题——振动噪声。因此降低压缩机的振动噪声对于提高车内乘坐舒适性是重要的一环。压缩机早期的研究都集中在制冷量和使用寿命等直接影响压缩机使用性能上,然而近年来人们对舒适性的要求进一步提高,压缩机的振动噪声问题越来越受到人们的关注。因此对压缩机振动噪声进行分析和优化是很有指导意义的,同时也可以对其他旋转机械和空气动力性设备的振动噪声问题提供借鉴。本文主要以当前应用最广泛的斜盘式空调压缩机为例对其振动噪声进行研究。首先,介绍了汽车空调系统的制冷循环过程以及十缸斜盘式压缩机结构和工作原理。并由此着重分析了压缩机的振动噪声产生机理,对其噪声从产生原因上分为机械噪声、流体噪声以及电磁噪声三类。其中机械噪声和流体噪声是影响最大的噪声源。同时针对不同的噪声形式提出相对应的控制原理。其次分别对压缩机及其支撑系统的模态以及压缩机内部流场噪声进行了仿真。对压缩机及其支撑系统模态仿真部分,是对其进行约束模态的计算。结果为计算得到的第一阶模态较小,在怠速情况下极易发生共振。对压缩机内部流场分析部分,根据压缩机空腔模型进行内部流场有限元模型,得到其流场噪声分布情况。然后介绍了压缩机及其支撑的模态试验和台架噪声试验。前者是在压缩机安车状态下使用敲击法来进行的,得到压缩机及其支撑的一阶模态为与计算得到结果相近,验证了模态计算的准确性。后者是在半消声室内由电机驱动,测量压缩机的近场噪声,得到怠速工况下对应的近场噪声与流场计算噪声相近,从而验证了流体噪声仿真的准确性。最后根据仿真结果及试验分析,从机械噪声和流体噪声两方面进行改进。在机械噪声改进方面,着重对压缩机支撑的结构进行改进,使压缩机及其支撑系统的一阶固有频率得到显著提高,避免了汽车怠速时压缩机共振的发生,同时将支架的质量减小,满足了轻量化要求。在流体噪声方面讨论了对压缩机的排气部位结构改进、增大气缸排气口直径、增大气缸长度以及改进一侧排气腔厚度并增大与气道连接的横截面积等方案逐一分析,确定最终改进方案,最终得到比较好的改进效果。
[Abstract]:With the rapid development of our country's economy, household cars have entered thousands of households, people's requirements for cars are also becoming higher and higher. The air conditioning system which can improve the riding conditions in the car has become an essential part of the purchase of cars, but the air conditioning compressor is the most important part of the air conditioning system. At the same time, another problem that can not be ignored is introduced. Therefore, reducing the vibration and noise of the compressor is an important link to improve the ride comfort in the car. The service life of the compressor directly affects the performance of the compressor. However, in recent years, the demand for comfort has been further improved, and the problem of compressor vibration and noise has attracted more and more attention. Therefore, it is very instructive to analyze and optimize the vibration and noise of compressor. At the same time it can also be used for reference to the vibration and noise of other rotating machinery and aerodynamic equipment. This paper mainly takes the most widely used tilted disc air conditioning compressor as an example to study its vibration and noise. First of all. This paper introduces the refrigeration cycle process of automobile air conditioning system, the structure and working principle of ten cylinder oblique disc compressor, and analyzes emphatically the mechanism of vibration and noise generation of compressor. The noise is divided into mechanical noise from the causes. Fluid noise and electromagnetic noise are three kinds of noise, among which mechanical noise and fluid noise are the most important noise sources. At the same time, the corresponding control principle is put forward for different noise forms. Secondly, the compressor and its supporting system are separately analyzed. The modal of compressor and its supporting system are simulated. The result is that the first order mode is small, and resonance is easy to occur in idle condition. The flow field analysis part of compressor is given. According to the compressor cavity model, the finite element model of internal flow field is carried out. The noise distribution of the flow field is obtained. Then the modal test of the compressor and its support and the bench noise test are introduced. The former is carried out by tapping method under the condition of compressor installation. The results of the first order mode of compressor and its support are similar to those obtained by the calculation, which verifies the accuracy of modal calculation, which is driven by motor in the semi-silencing chamber to measure the near-field noise of the compressor. It is obtained that the corresponding near-field noise under idle condition is close to the calculated noise of flow field, which verifies the accuracy of fluid noise simulation. Finally, according to the simulation results and experimental analysis. In terms of mechanical noise and fluid noise, the structure of compressor support has been improved, so that the first order natural frequency of compressor and its supporting system has been improved significantly. The resonance of compressor is avoided and the mass of support is reduced to meet the requirement of lightweight. The structure improvement of exhaust part of compressor is discussed in the aspect of fluid noise. By increasing the diameter of the exhaust port of the cylinder, increasing the length of the cylinder, improving the thickness of the side exhaust chamber and increasing the cross-sectional area between the side exhaust chamber and the port, the final improvement scheme is determined and the improvement effect is obtained.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.851

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