【摘要】：軸流泵的應(yīng)用極其廣泛，，涵蓋農(nóng)田灌溉、大型水電機組、艦艇的噴水推進等諸多方面，軸流泵在運行過程中的穩(wěn)定性問題一直是人們關(guān)注的重點，機組穩(wěn)定性不好，會引起較大的振動和噪聲，影響水泵的性能，嚴重時甚至會導致重大的安全事故。 引起軸流泵機組穩(wěn)定運行的因素主要包括機械結(jié)構(gòu)的振動以及流體壓力脈動。為了研究軸流泵壓力脈動和結(jié)構(gòu)振動特性，本文通過物理模型試驗的方法對軸流泵不同運行工況下的壓力脈動以及振動加速度信號進行了測試，并對測試信號進行了時、頻域和幅值分析，研究了軸流泵不同位置的壓力脈動和結(jié)構(gòu)振動特性以及不同流量對壓力脈動和結(jié)構(gòu)振動的影響規(guī)律。同時，通過試驗模態(tài)分析對水泵結(jié)構(gòu)的模態(tài)頻率進行了測試。 軸流泵機組的振動是機械因素和流體因素共同作用的結(jié)果，本文基于多輸入-單輸出模型，采用偏相干技術(shù)對引起機組振動的主要激勵源進行了識別，得到了各激勵源與評價點處信號的偏相干函數(shù)以及各激勵源的偏相干輸出譜，分析結(jié)果表明，在額定工況下，機械結(jié)構(gòu)的振動為主要激勵源，流體壓力脈動為次要激勵源。 在過渡過程中，軸流泵壓力脈動表現(xiàn)出明顯的非平穩(wěn)特性，為提取其壓力脈動信號中的特征信息，本文采用基于聚合經(jīng)驗模式分解（EEMD）和Hilbert變換的時頻分析方法對軸流泵壓力脈動信號進行分析。結(jié)果表明，該方法能夠準確地提取壓力脈動信號中的頻率成分及其時變情況。
[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.
【學位授予單位】：華中科技大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：TH312

【參考文獻】

相關(guān)期刊論文 前10條

1 賈嶸;王小宇;張麗;羅興

本文編號：2312670