Performance test and flow measurement of contra-rotating axial flow pump

In engineering, the highest operating head of the pumping station is usually controlled to be slightly lower than the lowest saddle bottom head of the axial-flow pump. However, in the practical operation, it is found that the highest operating head of the pumping station is obviously lower than the saddle bottom head of the pump device, which leads to the reduction of the operating range of the pumping station. To investigate the difference of lowest saddle bottom head between axial flow pump and axial flow pump device and apply it correctly, the energy performance tests of the TJ04-ZL-06 hydraulic model and its corresponding pump device were carried out to obtain the external curves, and numerical simulation was carried out to analyze and compare the internal flow field and pressure distribution. The results show that when the flow rate decreases, the first saddle-shaped region of the axial-flow pump and the saddle-shaped region of the pump device are caused by the decrease of the lift coefficient due to the increase of the attack angle between flow and blade. When the flow rate is less than 0.32Qd, the influence range of backflow in the inlet pipe is large, which leads to the high-pressure zone near the wall of the inlet pressure measurement section during the pump performance test, and hence the second saddle-shaped region of the axial-flow pump is essentially a measurement illusion. It is suggested that the inlet pressure measurement section should be set at least 4Dp away from the inlet flange of the impeller when testing the performance of the axial-flow pump under the condition of small flow rate, and the first saddle bottom head of the axial-flow pump or the saddle bottom head of the corresponding pump device can be considered as the control value of the highest head of the pumping station.

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Hydrodynamic Optimization for Design of a Submersible Axial-Flow Pump with a Swept Impeller

Energies ◽

10.3390/en13123053 ◽

2020 ◽

Vol 13 (12) ◽

pp. 3053

Author(s):

Youn-Sung Kim ◽

Man-Woong Heo ◽

Hyeon-Seok Shim ◽

Bong-Soo Lee ◽

Dong-Hwan Kim ◽

...

Keyword(s):

Performance Test ◽

Stokes Equations ◽

Three Dimensional ◽

Axial Flow ◽

Grid System ◽

Objective Functions ◽

Multi Objective Optimization ◽

Multi Objective ◽

Axial Flow Pump ◽

Flow Pump

Submersible pumps are now in high demand due to the sporadic occurrence of recent torrential rains. The current study was carried out to investigate the hydraulic characteristics of a submersible axial-flow pump with a swept impeller and to optimize the impeller and diffuser shapes of the pump to enhance the hydraulic performance. Three-dimensional Reynolds-averaged Navier–Stokes equations were solved with the shear stress transport turbulence model. The governing equations were discretized using the finite volume method, and unstructured tetrahedral and hexahedral meshes were used in the grid system. The optimal grid system was selected through a grid dependency test. A performance test for the submersible axial-flow pump was carried out experimentally, and the results of the numerical analysis were validated against the experimental results. The hydraulic efficiency and the total head were used as objective functions. For the first optimization, a multi-objective optimization was carried out to simultaneously improve the objective functions through a hybrid multi-objective evolutionary algorithm coupled with a response surface approximation by varying the swept angle and pitch angle of the blades of the rotating impeller. The second multi-objective optimization was performed using two design variables, i.e., the inlet angle and the length of the diffuser vanes, to simultaneously increase the objective functions. Clustered optimum designs in the Pareto optimal solutions yielded significant increases in the objective function values as compared with the reference design.

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Flow Measurement at Partial Flow Rate With LDV Around Rear Rotor of Contra-Rotating Axial Flow Pump

Volume 2: Fora, Parts A and B ◽

10.1115/fedsm2007-37467 ◽

2007 ◽

Author(s):

Shuichi Yamashita ◽

Satoshi Watanabe ◽

Kusuo Okuma ◽

Kyota Shirasawa ◽

Akinori Furukawa

Keyword(s):

Flow Field ◽

Flow Rate ◽

Flow Measurement ◽

Axial Flow ◽

Internal Flow ◽

Stable Operation ◽

Pressure Measurements ◽

Specific Speed ◽

Axial Flow Pump ◽

Flow Pump

An application of contra-rotating rotors, in which a rear rotor is employed in tandem with a front one and these rotors rotate in the opposite direction each other, has been proposed against a demand for developing higher specific speed axial flow pump. The internal flow field of pump should be considered in the design for higher performance and more stable operation. The flow field in contra-rotating axial flow pump was measured with LDV and wall pressure measurements. In the present paper, the experimental results are shown and the flow behaviors would be discussed.

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Study on the guide impeller of large axial flow pump

International Journal of Multiphase Flow ◽

10.1016/s0301-9322(97)88558-8 ◽

1996 ◽

Vol 22 ◽

pp. 145

Author(s):

J Chen

Keyword(s):

Axial Flow ◽

Axial Flow Pump ◽

Flow Pump

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Investigation into the Influence of Division Pier on the Internal Flow and Pulsation in the Outlet Conduit of an Axial-Flow Pump

Applied Sciences ◽

10.3390/app11156774 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6774

Author(s):

Fan Yang ◽

Dongjin Jiang ◽

Tieli Wang ◽

Pengcheng Chang ◽

Chao Liu ◽

...

Keyword(s):

Velocity Distribution ◽

Pressure Pulsation ◽

Axial Flow ◽

Hydraulic Loss ◽

Main Frequency ◽

Starting Position ◽

The Difference ◽

Axial Flow Pump ◽

Outlet Conduit ◽

Flow Pump

The outlet conduit is an important construction connecting the outlet of the pump guide vane and the outlet pool; in order to study the hydraulic performance of the straight outlet conduit of the axial-flow pump device, this paper adopts the method of numerical simulation and analyzes the influence of the division pier on the pressure and velocity distribution inside and near the wall of the straight outlet conduit based on three design schemes. Four pressure pulsation measuring points were arranged in the straight outlet conduit, and the low-frequency pulsation characteristic information inside the straight outlet conduit with and without the division pier was extracted by wavelet packet reconstruction. The results show that the addition of a division pier has an effect on the hydraulic loss, near-wall pressure and velocity distribution in the straight outlet conduit. A small high-pressure zone is formed near the wall at the starting position of the division pier, and a large high-speed zone is formed on the left side at the starting position of the division pier. The length of the division pier has no significant effect on the flow distribution of the straight outlet conduit and the pressure and velocity distribution near the wall. Under different working conditions, each monitoring point has the maximum energy in the sub-band (0~31.25 Hz). With the increase of the flow rate, the total pressure energy of the straight outlet conduit decreases gradually. Under each condition, the difference of the energy proportion of the horizontal monitoring points of the straight outlet conduit is small, and the difference of the energy proportion of the two monitoring points at the top and bottom of the outlet channel is relatively large. The energy of the two monitoring points in the straight outlet conduit with a division pier is smaller than that of the two monitoring points in the straight outlet conduit without a division pier. There are differences in the main frequency and the power spectrum corresponding to the main frequency of the monitoring points in the straight outlet conduit, and the reasonable setting of the division pier is conducive to reducing the pressure pulsation of the flow in the straight outlet conduit and is beneficial to the safe and stable operation of the pump device.

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