基于ANSYS Workbench的空调配管振动与应力的研究

发布时间：2018-03-10 06:43

本文选题：空调配管　切入点：有限元　出处：《华南理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：配管设计是空调结构设计的核心内容之一,它对于空调工作的稳定性具有至关重要的作用。除了满足系统制冷要求和产品空间结构需求,提高配管在空调工作过程中的可靠性、降低振动和应力一直是工程师们关注的焦点。传统的配管设计和改进主要依靠多次试制样机、反复试验测试的方法来完成,这往往需要耗费大量的人力财力。本文利用有限元技术对某型号空调样机的动态力学行为特征进行研究。利用ANSYS软件对其进行了模态、谐响应、及静力学分析。本文的结果和结论能为厂家深入理解配管失效机制并改进配管乃至整体结构提供帮助。压缩机机体的振动、配管内周期性气流脉动的冲击以及管内冷媒的持续高压,是配管发生疲劳破坏的重要原因。本文首先对样机的压缩机及其管路系统进行了建模,并进行了模态分析,结果显示系统的第七阶模态频率(46.34Hz)、第八阶模态频率(53.77Hz)与空调工作频率(50Hz)比较接近,易导致共振。对压缩机所受激励进行分解表明50Hz、100Hz、150Hz的激励成分起主要作用。谐响应的分析结果也显示在50Hz激励作用下,排气口后第一个U型弯曲处(U型段)的变形和应力非常大,这与系统的第七阶模态振型比较接近,可能有共振现象发生。其次,对配管内气流脉动产生的激励进行了计算,并将结果施加于配管各个弯头处进行谐响应分析,发现上述U型段仍是变形的最大区域,应力最大处位于配管与冷凝器的接口位置,但远小于压缩机机体振动所导致的应力结果。排气管段是管路系统压力最大的部分。本文最后对该段进行了流固耦合稳态计算,结果显示变形最大位置在上述U形管第一个弯头处。各个弯头以及管端固定处出现了应力集中的现象。随着弯头过渡圆弧的增大,管路的变形和应力逐渐减小。对比R10、R20、R30过渡圆弧弯头的排气管分析发现,R20弯头的变形和应力均较小,过大的圆弧对于减小应力应变的效果并不明显。本文建议采用R20的弯头以满足可靠性和经济性的要求。
[Abstract]:Piping design is one of the core contents of air conditioning structure design, which plays an important role in the stability of air conditioning. Reducing vibration and stress has always been the focus of engineers' attention. In this paper, finite element technique is used to study the dynamic mechanical behavior of a model air conditioning prototype. The modal, harmonic response of the prototype is analyzed by using ANSYS software. The results and conclusions of this paper can provide help for the manufacturers to understand the failure mechanism of piping and improve the piping and even the whole structure. The impact of periodic flow pulsation in the pipe and the continuous high pressure of the refrigerant in the pipe are the important reasons for the fatigue failure of the pipe. In this paper, the compressor and its pipeline system of the prototype are modeled, and the modal analysis is carried out. The results show that the 7th order modal frequency of the system is 46.34 Hz, and the 8th order modal frequency of the system is 53.77 Hz), which is close to the air conditioning frequency of 50 Hz. It is easy to cause resonance. The decomposition of the excitation of the compressor shows that the excitation composition of 50Hz / 100Hz / 100Hz plays a major role. The results of harmonic response analysis also show that the deformation and stress of the first U-shaped bend behind the outlet are very large under the excitation of 50Hz. This is close to the 7th order modal mode of the system, and there may be resonance. Secondly, the excitation caused by the flow pulsation in the pipe is calculated, and the results are applied to the harmonic response analysis at each bend of the pipe. It is found that the U section is still the largest deformation area and the maximum stress is located at the interface position between the pipe and the condenser. But it is far less than the stress result caused by the vibration of compressor block. The exhaust pipe section is the biggest pressure part of the pipeline system. Finally, the fluid-solid coupling steady state calculation of this section is carried out. The results show that the maximum deformation occurs at the first bend of the U-shaped tube, and the stress concentration occurs at each bend and at the end of the pipe. The deformation and stress of the pipeline gradually decreased. Comparing with the exhaust pipe analysis of the R10 / R20 / R30 transition arc elbow, it was found that the deformation and stress of the R20 elbow were smaller, The effect of excessive arc on reducing stress and strain is not obvious. In this paper, it is suggested that R20 elbows be adopted to meet the requirements of reliability and economy.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB657.2

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