Analysis of Disturbances for Modeling Pressure Pulsations in Pressure Systems of HPP

Author(s):  
O. A. Murav’ev ◽  
D. V. Rybin
Keyword(s):  
2021 ◽  
Vol 1086 (1) ◽  
pp. 012011
Author(s):  
A A Lepeshkin ◽  
L A Berdnikov ◽  
M G Korzhachkin ◽  
V A Panov

Author(s):  
Ning Zhang ◽  
Bo Gao ◽  
Chao Li ◽  
Dan Ni ◽  
Guoping Li

Effects of the staggered blades on unsteady pressure pulsations of a centrifugal pump with a specific speed ns=147 are investigated by the numerical simulation method. The obtained results are compared with the original blades. To clarify the resulting effects, eight monitoring points are used to extract pressure signals at three typical working conditions, and component at the blade passing frequency fBPF is emphasized. Results show that the pump efficiency and head will be reduced by the staggered blades, and at the nominal flow rate, the reduction is about 1.5% from comparison with the original blades. For all the eight points, the staggered blades contribute to the reduction of pressure amplitudes at fBPF when the pump works at three flow rates. The averaged reduction is 15.5% at the nominal flow rate. However, the negative effect on the second harmonic of fBPF will be caused by the staggered blades, and the corresponding pressure amplitude will increase at 2fBPF. It means that the pressure pulsation energy will be redistributed among the discrete components in pressure spectrum by the staggered blades. From the TKE distribution, it is found that the TKE values on the blade pressure side will be significantly affected by the staggered blades.


2019 ◽  
Vol 92 (6) ◽  
pp. 1517-1523
Author(s):  
A. V. Kiryukhin ◽  
O. O. Mil’man ◽  
A. V. Ptakhin ◽  
L. N. Serezhkin ◽  
S. A. Isaev
Keyword(s):  

1999 ◽  
Vol 157 (1-2) ◽  
pp. 237-252 ◽  
Author(s):  
Valko G. Petrov ◽  
Svetoslav G. Nikolov
Keyword(s):  

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Brandon J. Hopkins ◽  
Nikhil Padhye ◽  
Alison Greenlee ◽  
James Torres ◽  
Levon Thomas ◽  
...  

Wave-driven reverse osmosis desalination systems can be a cost-effective option for providing a safe and reliable source of drinking water for large coastal communities. Such systems usually require the stabilization of pulsating pressures for desalination purposes. The key challenge is to convert a fluctuating pressure flow into a constant pressure flow. To address this task, stub-filters, accumulators, and radially elastic-pipes are considered for smoothing the pressure fluctuations in the flow. An analytical model for fluidic capacitance of accumulators and elastic pipes are derived and verified. Commercially available accumulators in combination with essentially rigid (and low cost) piping are found to be a cost-effective solution for this application, and a model for selecting accumulators with the required fluidic-capacitance for the intended system is thus presented.


2014 ◽  
Vol 630 ◽  
pp. 375-382 ◽  
Author(s):  
Daniel Himr ◽  
Vladimir Haban

A pumping station in a fuel storage suffered from pressure pulsations in a petrodiesel pipeline. Check valves protecting the station against back flow made a big noise when disc hit a seat. Due to employees complaints we were asked to solve the problem, which could lead to serious mechanical problems. Pressure measurement in the pipeline showed great pulsations, which were caused by self-excited oscillation of control valves at the downstream end of pipeline. The operating measurement did not catch it because of too low sampling frequency. One dimensional numerical model of the whole hydraulic system was carried out. The model consisted of check valve, pipeline and control valve, which could oscillate, so it was possible to simulate the unsteady flow. When the model was validated, a vessel with nitrogen was added to attenuate pressure pulsations. According to the results of numerical simulation, the vessel was installed on the location. Subsequent measurement proved noticeably lower pulsations and almost no noise.


2021 ◽  
Vol 13 (13) ◽  
pp. 7125
Author(s):  
Daniel Himr ◽  
Vladimír Habán ◽  
David Štefan

The operation of any hydraulic power plant is accompanied by pressure pulsations that are caused by vortex rope under the runner, rotor–stator interaction and various transitions during changes in operating conditions or start-ups and shut-downs. Water in the conduit undergoes volumetric changes due to these pulsations. Compression and expansion of the water are among the mechanisms by which energy is dissipated in the system, and this corresponds to the second viscosity of water. The better our knowledge of energy dissipation, the greater the possibility of a safer and more economic operation of the hydraulic power plant. This paper focuses on the determination of the second viscosity of water in a conduit. The mathematical apparatus, which is described in the article, is applied to data obtained during commissioning tests in a water storage power plant. The second viscosity is determined using measurements of pressure pulsations in the conduit induced with a ball valve. The result shows a dependency of second viscosity on the frequency of pulsations.


1968 ◽  
Vol 94 (1) ◽  
pp. 310-311
Author(s):  
B. C. Syamala Rao ◽  
Amruthur S. Ramamurthy

Author(s):  
Quyang Ma ◽  
Guoan Yang ◽  
Mengjun Li

An elbow-shaped surge tank is proposed to suppress the pressure pulsations. The transfer matrix method was developed and the mathematical model was established to predict the distribution of pressure pulsations in the piping system (on which a surge tank was already installed) with an elbow-shaped surge tank. Simulation work of the whole piping system was performed. The results show that the elbow-shaped surge tank has good performance to attenuate the pressure pulsations. The frequency analysis shows that the amplitude for the first pulsation frequency is attenuated to a low level. The impulse response was analyzed to examine the efficiency of suppressing pulsations by using the suppressor. The theoretical analysis showed that there exists the optimal suppression performance when setting the distance between the elbow-shaped surge tank and the existing one. Meanwhile, modifying the ratio of length to diameter with a fixed surge volume could also impact the pressure pulsations. The analysis results can be used as a reference in designing and installing the elbow-shaped surge tank.


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