Review on Technology of Seawater Variable Speed Pumped Storage Generator Unit

He, Rufei; Zhang, Hao; Wang, Fang

doi:10.1109/ei250167.2020.9347224

Cited by 2 publications

(2 citation statements)

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“…However, many pumped storage units have problems with large pressure pulsations and violent vibrations when the working point operates in part load conditions and transient processes [3]. To solve the above problems, the variable-speed pumped storage power station [4] changes the rotational speed of the pump-turbine slightly to make the velocity triangles at runner inlet and outlet as close as possible to the optimal ones, in order to improve operating efficiency and reduce the amplitude of pressure pulsations. The variable-speed pump-turbine has been considered extensively in the design stage and can meet the requirements at the steady operation.…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional simulations of load rejection processes of a variable-speed pump-turbine under different initial rotational speeds

Yang,

Gong,

Fang

et al. 2024

J. Phys.: Conf. Ser.

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The load rejection transient process is one of the most dangerous operating conditions in pumped storage power stations. When the operating point slides through the S-shaped region quickly, the pressure fluctuations increase sharply and the unit vibrates obviously. In variable-speed units, the different initial rotational speeds have significant effects on the operating point trajectories during load rejection processes. In this paper, under the same head and guide vane opening, the load rejection processes with different initial rotational speeds were simulated by using three-dimensional methods, and the variations of rotational speed, discharge and torque were obtained and analyzed. The results show that the changes of initial rotational speeds affect the shapes of velocity triangle at the runner inlet and outlet, and causes the flow separations and vortices in the runner and draft tube, which leads to different efficiency and torque of the pump-turbine under initial steady conditions. In addition, during load rejection processes, the maximum values of macro parameters and pressure fluctuations, and the transitions of flow patterns have obvious differences because of these different initial rotational speeds.

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Section: Introductionmentioning

confidence: 99%

Three-dimensional simulations of load rejection processes of a variable-speed pump-turbine under different initial rotational speeds

Yang,

Gong,

Fang

et al. 2024

J. Phys.: Conf. Ser.

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“…Similar to conventional pumped storage units, seawater pumped storage units undertake the task of load and frequency control. As the hydraulic unit output power varies frequently, engineers often change the guide vane opening to adjust the volume of flow to adjust the output power [3,4]. However, the difference between seawater pumped storage hydropower plants and conventional pumped storage hydropower plants is that the lower reservoir of seawater pumped storage is located in the marine environment.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of the Internal Fluid Dynamics of Draft Tube in Seawater Pumped Storage Hydropower Plant

Wang

Meng

et al. 2023

Sustainability

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Pumped storage hydropower plants are renewable energy systems that are effective in saving energy and solving electricity peak-on shortage. Seawater pumped storage hydropower plants are a novel type of pumped storage hydropower plant specifically supplying electric power for ocean islands with the support of solar energy and wind energy. Compared with traditional pumped storage hydropower plants that are constructed on the mainland, seawater pumped storage hydropower plants should take the influence of the complex marine environment, such as extreme waves and winds, into consideration. Taking the characteristics of waves near islands in the East China Sea as an example, we explored the transient hydraulic characteristics in the draft tube of a pump turbine under wave disturbance using a sliding grid interface and the detached eddy simulation (DES) turbulence model. By analyzing the characteristics of unsteady flow in the draft tube, the vortex characteristics under the Q criterion, the frequency characteristics of the pressure pulsation, the evolution law of the internal fluid, and the propagation law of the pressure pulsation were explored. For the situation without wave disturbance, an obvious eccentric vortex in the straight cone section of the draft tube was observed in the case where the opening of the guide vane was small. With the increase in the opening of the guide vane, the eccentric vortex gradually dissipated. For the situation with wave disturbance, the main frequency of the draft tube equaled the frequency of the wave disturbance, the maximum pressure pulsation at the selected monitoring points increased 5 to 15 times, and the superposition of the wave pressure pulsation signals and the draft tube pressure pulsation produced more low-frequency, high-amplitude pressure pulsation signals. Even though the pressure pulsation frequency spectrum varied a lot, the frequency domain of the pressure pulsation without wave disturbance still existed. In addition, the wave disturbance merely varied with the pressure of the draft tube. The influence of wave disturbance on the pressure distribution in the draft tube was relatively small. The results can provide a reference for the operation of seawater pumped storage hydropower plants.

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Review on Technology of Seawater Variable Speed Pumped Storage Generator Unit

Cited by 2 publications

References 0 publications

Three-dimensional simulations of load rejection processes of a variable-speed pump-turbine under different initial rotational speeds

Three-dimensional simulations of load rejection processes of a variable-speed pump-turbine under different initial rotational speeds

Numerical Study of the Internal Fluid Dynamics of Draft Tube in Seawater Pumped Storage Hydropower Plant

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