CAJ | 학술논문

为了深入了解泵作透平不同流量不同转速下的振动噪声情况，在离心泵作透平开式试验台上，基于INV3020C 数据采集系统和透平测试系统建立了泵作透平振动噪声试验测试系统，实现了性能参数和振动噪声信号的同步采集。为研究泵反转作透平振动和水动力激励诱发的进出口噪声特性，以一台单级单吸离心泵作透平为研究对象，利用加速度传感器和水听器测量了泵作透平在不同转速及流量下的振动和噪声。试验结果表明：随着转速的增加，泵作透平的扬程增大，高效区范围增加，效率有所提高且最高效率点向大流量偏移，同时，泵体加速度的总有效值和进出口噪声总声压级也随转速的增加而增加；随流量的增加，各测点的振动加速度和声压级逐渐升高；泵体的振动强度高于其他测点，各测点的振动强度主要反映于水平向；相同流量下出口噪声的声压级高于进口。该研究可为泵作透平减振降噪提供参考。
위료심입료해빙작투평불동류량불동전속하적진동조성정황，재리심빙작투평개식시험태상，기우INV3020C 수거채집계통화투평측시계통건립료빙작투평진동조성시험측시계통，실현료성능삼수화진동조성신호적동보채집。위연구빙반전작투평진동화수동력격려유발적진출구조성특성，이일태단급단흡리심빙작투평위연구대상，이용가속도전감기화수은기측량료빙작투평재불동전속급류량하적진동화조성。시험결과표명：수착전속적증가，빙작투평적양정증대，고효구범위증가，효솔유소제고차최고효솔점향대류량편이，동시，빙체가속도적총유효치화진출구조성총성압급야수전속적증가이증가；수류량적증가，각측점적진동가속도화성압급축점승고；빙체적진동강도고우기타측점，각측점적진동강도주요반영우수평향；상동류량하출구조성적성압급고우진구。해연구가위빙작투평감진강조제공삼고。
Centrifugal pumps as turbine (PAT) are widely used in the petroleum and chemical industry with reasonable efficiency and low cost investment. And it represents the primary source of vibration and acoustic energy in industrial pipeline system. The amount of emitted energy may vary significantly between different designs and it is generally not well known. In order to better understand the flow-induced vibration and noise characteristics of centrifugal pump in reversible turbine operation, a single grade end suction centrifugal pump was chosen as research object. The fluid flows into the PAT through the outlet in pump mode and flows out through the inlet. A synchronous acquisition of performance parameters and vibration and noise signals were realized on the basis of INV3020C data acquisition system and performance test system in an open test loop. The liquid is pressurized through the booster pump, and then the high pressure liquid impacts the turbine impeller to make it rotate. The dynamometer consumes and measures the turbine’s energy. The operating condition was adjusted by regulating the frequency of frequency converter to change the booster pump’s capacity. Experimental studies on the vibration characteristic at different monitoring positions and acoustic characteristic at the upstream and downstream of PAT were carried out on the test bench, during which the rule and frequency characteristics of vibration and noise versus rotating speed were investigated at variable and constant flow rates. The vibration and flow noise signals were collected within 30 s using acceleration sensors and hydrophone at a sampling frequency of 20 kHz. The vibration measurements were performed on the bearing, pump casing, the inlet and outlet flange and the pump foot in horizontal and vertical directions with acceleration sensors (INV9822A). The noise was measured with flush-mounted hydrophones (ST70) located at 260 mm upstream and 400 mm downstream of PAT, which were four times of pipe diameters. The signals were amplified and recorded by INV3020C data acquisition system and FFT was used for computing the spectra with the Hanning window for reducing the spectrum leakage. Experimental results show that, with the increase of rotational speed, the head and shaft power of PAT increases, and the highest efficiency point moves to larger flow rate with wider high-efficiency range. Under a certain speed, the vibration acceleration under the same monitoring point grows with the increase of flow rates. Meanwhile, the vibration energy of PAT is focused on the high frequencies, and the vibration enhances with the increase of rotating speed. The vibration strength of volute is higher than that of other measuring points for larger flow rates. The vibration strength of each measuring point comes mainly from the horizontal direction. Under a certain speed, the sound pressure level gradually grows with the increase of flow rates. Because the noise mainly comes from the interaction of blade and tongue closer to the outlet, and the radiated noise is hindered by the casing and impeller, the sound pressure level of downstream is higher than that of upstream under the same flow rate. The total sound pressure level basically increases with the increase of rotating speed.