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轴流泵出水流道水力损失试验研究 总被引:2,自引:0,他引:2
受导叶出流环量、出水弯管二次流等因素的影响,轴流泵单孔出水流道内为复杂的螺旋流,双孔出水流道左孔流量大于右孔流量,水力损失异常。采用五孔探针准确测定流道断面水流能量,实测分析出水流道水力损失特性,探讨减阻措施。结果表明,出水流道水力损失不符合与流量平方成正比的关系。与等圆出水管相比,渐扩出水流道可以减小水力损失,提高泵装置效率10%~30%;对单孔流道,轴流泵出口环量过大,增大了水力损失, 而微小环量会使水力损失略有减小;对双孔流道,两孔流量不等,存在偏流,水力损失增大。采用微小出流环量或无出流环量后导叶,可减小出水流道水力损失,提高泵装置效率6%-11%。 相似文献
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During the process of designing the mixed-flow pump impeller, the meridional flow passage shape directly affects the obtained meridional flow field, which then has an influence on the three-dimensional impeller shape. However, the meridional flow passage shape is too complicated to be described by a simple formula for now. Therefore, reasonable parameter selection for the meridional flow passage is essential to the investigation. In order to explore the effects of the meridional flow passage shape on the impeller design and the hydraulic performance of the mixed-flow pump, the hub and shroud radius ratio (HSRR) of impeller and the outlet diffusion angle (ODA) of outlet zone are selected as the meridional flow passage parameters. 25 mixed-flow pump impellers, with specific speed of 496 under the design condition, are designed with various parameter combinations. Among these impellers, one with HSRR of 1.94 and ODA of 90° is selected to carry out the model test and the obtained experimental results are used to verify accuracies of the head and the hydraulic efficiency predicted by numerical simulation. Based on SIMPLE algorithm and standard k-ε two-equation turbulence model, the three-dimensional steady incompressible Reynolds averaged Navier-Stokes equations are solved and the effects of different parameters on hydraulic performance of mixed-flow pump impellers are analyzed. The analysis results demonstrate that there are optimal values of HSRR and ODA available, so the hydraulic performance and the internal flow of mixed-flow pumps can be improved by selecting appropriate values for the meridional flow passage parameters. The research on these two parameters, HSRR and ODA, has further illustrated influences of the meridional flow passage shape on the hydraulic performance of the mixed-flow pump, and is beneficial to improving the design of the mixed-flow pump impeller. 相似文献
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本文从液压泵相关液压油路的设计、液压泵的安装、液压泵的运行三个方面介绍液压泵在设计和运行中的注意事项,对液压泵的正确使用有一定的指导意义。 相似文献
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旋涡泵内部流动理论不完善,其叶轮和流道水力尺寸计算通常采用相似计算法和经验统计计算法。文中针对这两种方法在应用中存在的诸多局限性,提出了基于人工神经网络的智能算法。该方法既不以寻求相似的模型泵并进行换算为基础,也不以统计方法获取经验数据,而是以现有旋涡泵产品数据为基础,应用神经网络构建旋涡泵性能参数与水力尺寸之间的关系模型,从而实现泵的性能参数与水力尺寸的非线性映射,并利用这一关系模型进行新产品设计。文中介绍了这一方法的基本原理和关键技术,其中包括神经网络的结构设计、模型选择、样本对设计和网络训练等。解决了由于旋涡泵叶轮和流道结构型式繁多、设计中缺乏足够的经验数据支持及缺乏统一的经验统计方法的问题,提供了使不同企业能够有效地利用已有产品开发新产品的统一方法,该方法不仅支持知识重用,而且具有通用性,对提高旋涡泵的设计质量和缩短设计周期具有重要意义。 相似文献
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In the mixed-flow pump design, the shape of the flow passage can directly affect the flow capacity and the internal flow, thus influencing hydraulic performance, cavitation performance and operation stability of the mixed-flow pump. However, there is currently a lack of experimental research on the influence mechanism. Therefore, in order to analyze the effects of subtle variations of the flow passage on the mixed-flow pump performance, the frustum cone surface of the end part of inlet contraction flow passage of the mixed-flow pump is processed into a cylindrical surface and a test rig is built to carry out the hydraulic performance experiment. In this experiment, parameters, such as the head, the efficiency, and the shaft power, are measured, and the pressure fluctuation and the noise signal are also collected. The research results suggest that after processing the inlet flow passage, the head of the mixed-flow pump significantly goes down; the best efficiency of the mixed-flow pump drops by approximately 1.5%, the efficiency decreases more significantly under the large flow rate; the shaft power slightly increases under the large flow rate, slightly decreases under the small flow rate. In addition, the pressure fluctuation amplitudes on both the impeller inlet and the diffuser outlet increase significantly with more drastic pressure fluctuations and significantly lower stability of the internal flow of the mixed-flow pump. At the same time, the noise dramatically increases. Overall speaking, the subtle variation of the inlet flow passage leads to a significant change of the mixed-flow pump performance, thus suggesting a special attention to the optimization of flow passage. This paper investigates the influence of the flow passage variation on the mixed-flow pump performance by experiment, which will benefit the optimal design of the flow passage of the mixed-flow pump. 相似文献
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液压泵是液压系统中的"心脏",当液压系统出现问题时,首先想到液压泵。通过对各种液压泵故障的分析,列出了常见故障及产生原因,最后找出解决方法并探讨了液压泵的合理使用。 相似文献
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Based on structures and characteristics of traditional hydraulic pumps, this paper proposes a novel high-temperature and high-pressure
hydraulic pump (HHHP) that can work under 150°C and 28 MPa to overcome problems of traditional high-temperature plunger pumps.
The HHHP is designed with the structure of mechanical division and double cylinder parallel. The control signals of two cylinders
are two separate triangle waveforms with 90° phase difference. Because the output waveforms of two cylinders have the same
characteristics as the control signals, the HHHP can obtain a stable output after two separate waveforms are superposed. A
mononeuron self-adaptive PID control algorithm is also improved by modifying parameters K and η. Two improved controllers
are used to control the two cylinders, respectively, making two displacements of plungers match each other. Therefore, reduced
fluctuations and stable pressure output is obtained. Besides simulation, tests on the built prototype test system are carried
out to verify the performance of HHHP. Results show that the improved control approach can limit fluctuations to a lower level
and the HHHP system attains good outputs under different signal periods and different pressures. 相似文献
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Eryun Chen Zuiling Ma Gaiping Zhao Guoping Li Ailing Yang Guofang Nan 《Journal of Mechanical Science and Technology》2016,30(12):5397-5404
Full-scale structural vibration and noise induced by flow in an axial-flow pump was simulated by a hybrid numerical method. An unsteady flow field was solved by a large eddy simulation-based computational fluid dynamics commercial code, Fluent. An experimental validation on pressure fluctuations was performed to impose an appropriate vibration exciting source. The consistency between the computed results and experimental tests were interesting. The modes of the axial-flow pump were computed by the finite element method. After that, the pump vibration and sound field were solved using a coupled vibro-acoustic model. The numerical results indicated that the the blade-passing frequency was the dominant frequency of the vibration acceleration of the pump. This result was consistent with frequency spectral characteristics of unsteady pressure fluctuation. Finally, comparisons of the vibration acceleration between the computed results and the experimental test were conducted. These comparisons validated the computed results. This study shows that using the hybrid numerical method to evaluate the flow-induced vibration and noise generated in an axial-flow pump is feasible. 相似文献
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320 t鱼雷罐车担负着高炉与炼钢厂之间的铁水运输任务,是钢铁生产链上的重要环节,而润滑液压泵是鱼雷罐车润滑系统的关键部件.本文分析润滑液压泵的常见故障,并提出可行的解决方案. 相似文献
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将数值优化技术与CFD流场计算相结合,由数学过程代替设计人员的经验,控制叶片设计修改方向,构建轴流泵叶片自动优化设计平台。以多学科优化软件iSIGHT为基础,以现有优秀的轴流泵叶片模型为研究对象,建立了参数化建模、网格划分、流场计算和数值优化相结合的轴流泵叶片自动优化设计平台。以叶轮效率最高为目标函数,以扬程和汽蚀余量为约束条件,用该平台对设计工况下的初始叶片进行自动优化设计。对比分析优化前后叶片的水力性能,优化后叶片的水力性能有所提高,表明本文采用的自动优化设计方法是有效和可行的。 相似文献
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针对液压泵振动信号通常具有非线性强和信噪比低的特点,提出了一种基于改进多重分形去趋势波动分析(MF-DFA)和半监督马氏距离模糊C均值(SSM-FCM)的液压泵退化状态识别方法。该方法首先引入滑动窗口技术改进传统MF-DFA方法在时间序列数据分割过程中存在的不足,提高MF-DFA方法的计算精度;然后利用改进MF-DFA方法计算液压泵多重分形谱参数,并分析了不同分形谱参数对液压泵退化状态的反映能力,选取奇异指数α_0和广义Hurst指数波动均值Δh(q)作为退化特征量;最后利用半监督马氏距离模糊C均值方法实现了液压泵退化状态识别,并以液压泵实测数据为例验证本文所提方法的有效性。 相似文献