轴流泵振源的特性分析与识别技术研究
发布时间：2018-11-05 16:40
【摘要】：轴流泵的应用极其广泛，，涵盖农田灌溉、大型水电机组、舰艇的喷水推进等诸多方面，轴流泵在运行过程中的稳定性问题一直是人们关注的重点，机组稳定性不好，会引起较大的振动和噪声，影响水泵的性能，严重时甚至会导致重大的安全事故。 引起轴流泵机组稳定运行的因素主要包括机械结构的振动以及流体压力脉动。为了研究轴流泵压力脉动和结构振动特性，本文通过物理模型试验的方法对轴流泵不同运行工况下的压力脉动以及振动加速度信号进行了测试，并对测试信号进行了时、频域和幅值分析，研究了轴流泵不同位置的压力脉动和结构振动特性以及不同流量对压力脉动和结构振动的影响规律。同时，通过试验模态分析对水泵结构的模态频率进行了测试。 轴流泵机组的振动是机械因素和流体因素共同作用的结果，本文基于多输入-单输出模型，采用偏相干技术对引起机组振动的主要激励源进行了识别，得到了各激励源与评价点处信号的偏相干函数以及各激励源的偏相干输出谱，分析结果表明，在额定工况下，机械结构的振动为主要激励源，流体压力脉动为次要激励源。 在过渡过程中，轴流泵压力脉动表现出明显的非平稳特性，为提取其压力脉动信号中的特征信息，本文采用基于聚合经验模式分解（EEMD）和Hilbert变换的时频分析方法对轴流泵压力脉动信号进行分析。结果表明，该方法能够准确地提取压力脉动信号中的频率成分及其时变情况。
[Abstract]:The application of axial flow pump is extremely extensive, covering many aspects, such as farmland irrigation, large hydropower units, water jet propulsion of warships, etc. The stability of axial flow pumps in the operation process has been the focus of attention, the unit stability is not good. It will cause large vibration and noise, affect the performance of the pump, and even lead to serious safety accidents. The main factors that cause the stable operation of axial-flow pump unit include the vibration of mechanical structure and fluid pressure pulsation. In order to study the pressure pulsation and structural vibration characteristics of axial flow pump, the pressure pulsation and vibration acceleration signal of axial flow pump under different operating conditions were measured by physical model test method, and the test signals were measured. Based on the analysis of frequency domain and amplitude, the characteristics of pressure pulsation and structural vibration of axial flow pump at different positions and the influence of different flow rate on pressure pulsation and structural vibration are studied. At the same time, the modal frequency of the pump structure is tested by experimental modal analysis. The vibration of axial-flow pump unit is the result of the interaction of mechanical and fluid factors. Based on the multi-input-single-output model, the main excitation sources that cause the vibration of the unit are identified by partial coherence technique in this paper. The partial coherence function of each excitation source and the signal at the evaluation point and the partial coherent output spectrum of each excitation source are obtained. The analysis results show that the vibration of the mechanical structure is the main excitation source and the fluid pressure fluctuation is the secondary excitation source under rated working conditions. In the process of transition, the pressure pulsation of the axial flow pump shows obvious non-stationary characteristics, in order to extract the characteristic information from the pressure fluctuation signal of the axial flow pump, In this paper, the pressure pulsation signal of axial flow pump is analyzed by time-frequency analysis method based on polymeric empirical mode decomposition (EEMD) and Hilbert transform. The results show that this method can accurately extract the frequency components and time-varying conditions of pressure fluctuation signals.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH312
[Abstract]:The application of axial flow pump is extremely extensive, covering many aspects, such as farmland irrigation, large hydropower units, water jet propulsion of warships, etc. The stability of axial flow pumps in the operation process has been the focus of attention, the unit stability is not good. It will cause large vibration and noise, affect the performance of the pump, and even lead to serious safety accidents. The main factors that cause the stable operation of axial-flow pump unit include the vibration of mechanical structure and fluid pressure pulsation. In order to study the pressure pulsation and structural vibration characteristics of axial flow pump, the pressure pulsation and vibration acceleration signal of axial flow pump under different operating conditions were measured by physical model test method, and the test signals were measured. Based on the analysis of frequency domain and amplitude, the characteristics of pressure pulsation and structural vibration of axial flow pump at different positions and the influence of different flow rate on pressure pulsation and structural vibration are studied. At the same time, the modal frequency of the pump structure is tested by experimental modal analysis. The vibration of axial-flow pump unit is the result of the interaction of mechanical and fluid factors. Based on the multi-input-single-output model, the main excitation sources that cause the vibration of the unit are identified by partial coherence technique in this paper. The partial coherence function of each excitation source and the signal at the evaluation point and the partial coherent output spectrum of each excitation source are obtained. The analysis results show that the vibration of the mechanical structure is the main excitation source and the fluid pressure fluctuation is the secondary excitation source under rated working conditions. In the process of transition, the pressure pulsation of the axial flow pump shows obvious non-stationary characteristics, in order to extract the characteristic information from the pressure fluctuation signal of the axial flow pump, In this paper, the pressure pulsation signal of axial flow pump is analyzed by time-frequency analysis method based on polymeric empirical mode decomposition (EEMD) and Hilbert transform. The results show that this method can accurately extract the frequency components and time-varying conditions of pressure fluctuation signals.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH312
【参考文献】
相关期刊论文 前10条
1 贾嵘;王小宇;张丽;罗兴
本文编号：2312670
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