bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis and Discussion on High Insulation Performance of 20 kV Generator Motor Stator in the Large Pumped Storage Unit
Authors: Zhou Z , Liu T , Chen H Y , Cao Z X , Li H C 
Published: June 2024

Abstract
The terminal voltage of 400 MW 500 r/min generator motor in a large pumped storage power station is 20 kV, in which the height of stator core is 3400 mm and the stator bar adopts less glue VPI (Vacuum Pressure Impregnating) process. The characteristic of this generator motor is high voltage level, large external size and high technical requirements. As the pumped storage unit with the highest voltage level that has been put into operation in China, its stator system of 20 kV generator motor shows excellent insulation performance during the test process. This paper analyzes and discusses from two perspectives of development and installation, and summarizes the key technologies in the process, which can be used for further reference in similar projects.
Analysis and research on the influence of stress relief structure on the grouting hole weld of hydraulic and hydropower penstock
Authors: Cao ZhengXin , Yan Feng , Zhang Xie , Zhou Zan , Liu LiAng , liu Tao 
Published: June 2024

Abstract
After the opening and grouting of the penstock in water conservancy and hydropower projects, the grouting hole needs to be sealed tightly, and the conventional plugging is required. There is large residual stress at the weld of the plugging hole, which is easy to produce welding cracks. In this paper, the sensitivity of stress relief groove added to the grouting hole plugging plug of hydraulic and hydropower penstock to the stress concentration of the plugging hole on the penstock is studied. Then a comparative experiment was carried out. The results of non-destructive testing, residual stress testing, mechanical property testing and metallographic testing of the test sample welds showed that the grouting hole plugging plug was equipped with a stress release structure, the overall strength of the grouting hole plugging weld was basically unchanged, and the stress concentration was significantly reduced. For the plugging and welding of grouting holes in hydraulic and hydropower penstocks, it is recommended to set a stress relief structure on the plugging plug to effectively reduce the impact of stress concentration on welding cracks[1].
Grounding Resistance Monitoring Device for Improved Construction Electricity Safety in Pumped Storage Power Station Construction
Authors: Wang H B , Zhang Z J 
Published: June 2024

Abstract
During the construction period of pumped storage power stations, there are prominent safety hazards in the use of electricity. Most of the underground chambers are in rocky environments, and it is difficult to meet the standard requirements for the grounding resistance of nearby distribution boxes. In addition, due to the high humidity and large amount of dust in the chambers, the grounding terminals are prone to oxidation. Furthermore, frequent blasting operations can cause poor contact of the grounding terminals, resulting in the inability to effectively guide the leakage current into the earth and causing electric shock injury. By using the TN-S wiring method, the leakage current of the equipment and distribution box is guided into the ground grid through the PE line. At the same time, a real-time monitoring system is established for the PE line, which monitors the integrity of the PE line resistance between the third-level distribution box and the transformer ground grid. When an integrity failure occurs, an alarm is quickly issued, enabling maintenance personnel to promptly detect and repair the fault, ensuring that all leakage currents have a good export channel, and further guaranteeing the safety of electricity users.
Effect of the number of orifice plate stages on cavitation characteristics
Authors: Li Dawe , Wang Chengjun , Ju Pengbo , Han Guihua , Jin Di , Wen Jiangbo 
Published: June 2024

Abstract
In order to study the influence of the number of stages of the orifice cavitator on the effect of hydraulic cavitation, this paper adopts the numerical simulation method, with the help of pressure cloud map, gas content cloud map and turbulent kinetic energy cloud map, to observe the distribution location of low pressure area, meteorological area change law, and take the average gas content and maximum gas content rate as the criteria for judging cavitation strength, and quantitatively analyze the influence of different stages on the cavitation characteristics of orifice plate. In this experiment, purified water was used as the medium, and the conductivity of water after cavitation was measured by lightning magnetic conductivity meter to study the characteristics of cavitators of different series of orifice plates and verify the laws of numerical simulation. The experimental results show that at the same inlet flow rate and the same outlet pressure, the number of stages of the cavitator gradually increases, and the cavitation effect is weakened. This is consistent with the numerical simulation results.
Experimental Study on the Movement Law of Solid-liquid Two-phase Flow in slurry Pump
Authors: Xing Jin , Cheng Shufeng , Guo Tao 
Published: June 2024

Abstract
The foundation for the research of two-phase flow pumps is the movement law of solid-liquid two-phase flow in the pump. Currently, research in this direction is mostly conducted through numerical simulation technology, while experimental research is less. In this paper, through the development of a transparent two-phase flow pump, a visual pump test platform with a pipe diameter of 150 mm has been built, and a large number of experimental studies have been conducted on the motion laws of solid-liquid two-phase flow in the pump. The motion laws of particles with different particle diameters in the pump under different flow rates and rotational speeds were obtained through high-speed cameras, including particle velocity and trajectory, and particle collision with the wall. Meanwhile, the wear tests on the pump were carried out with a cast steel and medium high concentration sand pump. The test results show that the location where particles collide with the wall surface more frequently is also the location where wear is more severe. Based on the above test research results, the optimization design direction for two-phase flow pumps is proposed.
Sludge solubilization method using hydrodynamic cavitation
Authors: Son Hyungjoon , Yong Yoon Joon , Sun Xun 
Published: June 2024

Abstract
This study investigates the effects of hydrodynamic cavitation(HC) on sludge solubilization using an advanced rotation hydrodynamic cavitation reactor(ARHCR), varying rotation speeds of rotor. The effectiveness was analysed by measuring biogas yield during anaerobic digestion(AD). The results show that AD performance with treated sludge was improved by HC, indicating that sludge was effectively solubilized. However, the much higher temperature formed by HC leads to the formation of refractory materials that lower AD performance. Overall, this study suggests that HC can be a promising technique to improve sludge solubilization, however, the issue of refractory materials needs to be addressed for optimal performance.
Experimental investigation into lock-in characteristics of the composite hydrofoils
Authors: Ji Miaomiao , Zhang Housheng , Wu Qin , Huang Biao , Wang Guoyu 
Published: June 2024

Abstract
This study experimentally investigates the lock-in characteristics of structural vibration of hydrofoils made of CFRP composite material. The synchronous experimental measurement system constituted of high-speed framing camera, LDV, velocity and pressure regulation systems are set up. It can be found that the Com+45° hydrofoil accelerates the cavitation inception, and the Com-45° hydrofoil defers it. The evolution of the dominant vibration frequency and cloud cavity shedding frequency are semblable. As the cavitation evolution gradually develops, the larger dominant frequency reduces, while the lower frequency remains unchanged. The scope of frequency lock-in meets the magnitude relationship Com+45° hydrofoil> Com-45° hydrofoil> Com0° hydrofoil. The wavelet transformation of structural vibration displacement and non-dimensional cavity area shows that both f
shed and f
shed,lock-in exist in the lock-in condition.
Analysis of propellant management performance in a tank with vertical vanes by drop tower test
Authors: Liu J T , Long J , Chen L , Qu Z , Yao C , Ye W X 
Published: June 2024

Abstract
A drop tower test system for microgravity experiment was established to analyze the performance of a propellant management device (PMD) with vertical vanes. The microgravity level was 10-3 g. Different volume fractions of liquid and different gravity directions were used to study the performance of the PMD. The changes in the gas-liquid interface were studied during the test. It was shown that the vane-type tank is suitable for reverse maneuvering process when volume fraction of propellant is more than 5%, and the propellant relocation time from high gravity condition to microgravity is less than 1.6 s. The inertia force weakens rapidly and the surface tension gradually plays a dominant role at the initial short time period (t<0.4s). The potential energy will be released during the initial short time period (t≤0.5s). The vane-type tank is not suitable for a lateral strong maneuvering process when the propellant volume fraction is less than 2%. The quantity and duration of thruster must be strictly controlled when the volume fraction is less than 10%. The above results provide a favorable reference for the further optimization of PMD designs.
Study on the Flow Characteristics of Piston Type Flow and Pressure Regulating Valve under Sand Containing Conditions
Authors: Fu Y , Du S M , An Z J , Deng L L 
Published: June 2024

Abstract
Based on numerical simulation, the flow characteristics of the valve under different opening degrees of sandy conditions are studied based on the Realizable k-ε turbulence model and Eulerian multiphase flow model, and the flow characteristic curves and flow coefficient-opening degree curves of the valve are obtained, and the influence of the sand rate on the valve flow is analyzed with the numerical calculation results. The results show that with the increase of sand content rate and valve opening, sediment deposition is easily formed in the throttle orifice area, which affects the normal flow inside the valve body and leads to a large deviation of the valve flow rate from the theoretical flow rate. In addition, the relationship between flow rate, sand content and flow coefficient is obtained by fitting the data to the numerical calculation results. The research results have certain reference value for the structural optimization and efficient operation of the valve.
Numerical simulation of gas-liquid interface in a blade type propellant tank
Authors: Chen L , Li Y , He X M , Yao C , Yang N J , Xue L 
Published: June 2024

Abstract
Currently, most of the satellite propulsion systems are mainly on chemical propulsion, and liquid propellant is the necessary power fuel for the propulsion system. The propellant tank of the satellite is a critical unit used to store and manage propellant. The hard core of the blade type tank is the Propellant Management Device (PMD), which serves to provide non entrained propellant for the propulser under specified flow and acceleration conditions during all phases of satellite operation. In this paper, the management performance of propellant under microgravity environment in the tank of a blade type is studied. Using the VOF model, the liquid management performance under microgravity environment in the tank is numerically simulated. The repositioning process is numerical simulated. The good management performance of the tank is verified, and the fluid distribution law is obtained, which can provide guidance for the design of the blade type tank.
Effect of runner radial installation deviation on the flow characteristics of the 1000MW turbine
Authors: Wang Yifan , Huang Xingxing , Zhou Lingjiu 
Published: June 2024

Abstract
The flow simulation of a hydraulic turbine is not limited to calculations and analyses under ideal conditions and simplified models, but it should also consider the existence of radial installation deviations in actual operating conditions and their influence on the flow of the turbine. Therefore, this study focuses on a 1000MW unit and analyzes the internal flow characteristics under actual operating conditions while considering the radial installation deviations of the turbine wheel. The results show that the absolute value of pressure increases with the increase of radial deviation, but the difference value remains almost constant. And it also indicates that the magnitude of the radial forces increases with the increase in radial installation deviations. There are two linear relationship curves, one before 0.5mm and one after 0.5mm, with the latter growing at a faster rate. Furthermore, taking the crown as an example, the influence of the wall velocity-generated dynamic pressure on the clearance is different. Lastly, considering the magnitude of the combined forces and vibration amplitude, the crown is the most critical part that should be given attention. The research findings can guide the high-quality installation of 1000MW units during major overhauls and provide valuable technical references for similar units. The research outcomes can also guide the initial installation and major overhaul stages of 1000MW units and offer beneficial technical references for other similar units.
Research on Closing Law of Guide Vane in a Francis turbine during the Load Rejection Process
Authors: Wang Xiu , Yan Yan , Wang Wen-Quan 
Published: June 2024

AbstractIt has become a general trend for new energy to be connected to the power grid, and the tasks of peak and frequency regulation undertaken by hydropower units are tough. Inevitably, the Francis turbine operates under a transient process, which brings serious pressure fluctuations and instability problems. In the present study, a three-dimensional simulation of Francis turbines with the water pipeline system during the load rejection process is carried out. Results indicated that when a straight line is used to close guide vanes, the Francis turbine generates significant rotational speed, which poses a threat to system safety and stability. Based on this, the sinusoidal closing law proposed in the present study can effectively reduce the maximum rotational speed by 2.6%. After the end of load rejection, the difference in rotational speed between the two closing laws is 5.15%.
Analysis of the velocity non-uniformity in waterjet inlet duct
Authors: Shen Z H , Li W , Pan Z Y 
Published: June 2024

Abstract
Since the waterjet propulsion unique advantages, it’s applied more widely. But the Inlet duct and other structures prone to particular flows. Since the inlet duct of a special structure, the velocity distribution shows non-uniformity, departing from the waterjet pump design scenarios. In this paper, waterjet pump is simulated to study its velocity non-uniform of inlet duct and to investigate the discipline of the velocity distribution. By changing the inlet boundary conditions, the corresponding velocity field is obtained, to analyze the results under different conditions. It is researched the effect of inlet duct velocity non-uniformity on waterjet propulsion system.
Experimental study of the effects on performance of Francis turbine due to sediments in flow
Authors: Poudel Ravi , Shi Junde , Zhao Zilong , Qian Zhongdong , Guo Zhiwei , Chitrakar Sailesh , Thapa Bhola 
Published: June 2024

Abstract
The sediments in the flow cause deterioration of components of the hydraulic machinery and influence fundamental properties such as density and viscosity of the flowing fluid. Earlier researchers have demonstrated the influence of sediment-laden flow on the performance of pumps, but such investigations have not been performed for the Francis turbine. This research focused on the effects of sediment-laden flow on the performance of a Francis turbine. Hydropower Research Centre for Himalayan Region (HRCHR) had a laboratory facility especially designed to conduct tests on Francis Turbines with sediments in the flow. The test rig was a closed-loop type and had provisions for mixing sediments with water and maintaining a uniform sediment concentration throughout the circuit. The performance of a 2 kW Francis turbine was tested at three different GV (Guide Vane) angles for different load conditions with and without sediment in the flow. The results showed that there was no change in maximum efficiency in the case of a smaller GV opening, whereas the maximum efficiency in the case of sediment water was reduced for a larger GV opening. Meanwhile, Sediment particles did not affect the head under the same discharge, whereas output power decreased slightly for sediment-laden conditions.
Numerical analysis of the sand hydro-abrasion of a Pelton turbine injector
Authors: Quanwei Liang , Jie Liu , Yexiang Xiao , Yilin Zhu , Hengte Zhou , Haifeng Deng 
Published: June 2024

Abstract
Pelton turbines have great application prospects in the exploitation of high-head hydraulic resources. However, sediment abrasion within its components is the major challenge. In this paper, Euler-Lagrangian method is used to simulate the flow process of the sediment particles in Pelton turbines injector numerically. The hydraulic characteristics of the three-phase flow, the behaviour of the sediment particles and the abrasion distribution are also analysed in detail. Calculation result shows that the predicted motion characteristics of the particles are in good agreement with theoretical model, and the predicted abrasion distribution also matches well with the measured results.
Effectiveness of Air Admission through Short Pipes in Reducing Pressure Fluctuation of Propeller Hydro-turbine Flow Channel
Authors: Wu Huanyu , Luo Yongyao , Jin Faye , Zeng Chongji , Liu Xin 
Published: June 2024

Abstract
When the hydro-turbine operates under part-load conditions, a large-scale vortex flow will form in the draft tube. This vortex can cause low-frequency pressure pulsations that endanger the safe operation of the hydro-turbine. By injecting air into the draft tube, the structure of the vortex can be effectively disrupted, reducing the amplitude of the pressure pulsations. In this paper, a propeller hydro-turbine was studied, and the SST k-ω turbulence model based on the Reynolds averaged Navier-Stokes equations (RANS) was utilized to perform a full-channel unsteady numerical simulation on a part-load condition with the guide vane opening (GVO) of 35°. Then, the fast Fourier transform (FFT) was applied to analyze the pressure fluctuations at monitoring points on the draft tube wall, the head cover, and the nose of the spiral casing. The results indicated that injecting air with an appropriate flow rate into the draft tube through short pipes can reduce the pressure fluctuations on the draft tube wall by 51.4% to 72.5% and decrease the pressure fluctuations on the head cover and the nose of the spiral casing by approximately 40% to 42%. This study proposes a new air admission structure that can enhance the operating stability of the propeller hydro-turbine under part-load conditions.
Study on the Influence of Geometric Parameters on Vibration Characteristics of Hydraulic Oscillator Used in Oil Drilling
Authors: Tang Peng , Zhao Haoru , Zhu Baoshan , Lu Jiaxing , Zhang Wenwu 
Published: June 2024

Abstract
Hydraulic oscillator is an important drilling equipment extensively used in petroleum extraction and drilling work. It generates vibration along the axis direction to drive the drilling tool to drill and the drilling effect largely depends on the axial impulsive loading and frequency of the hydraulic oscillator. However, few present studies have been conducted on the influence of variations in key geometric parameters on axial impulsive loading and frequency of hydraulic oscillators, and systematic analysis is still lacking. Optimization calculations were carried out on throat inner diameter, throat length, nozzle spacing, and nozzle angle of the hydraulic oscillator. The analysis results show that: The overall impact of throat length and nozzle angle changes on axial load is small, while throat inner diameter has the greatest impact on the axial load. The axial load is 375.78 N when throat inner diameter is 10 mm, which is 8 times larger than that when throat inner diameter is 20 mm. Moreover, the throat inner diameter is smaller, both the axial load and amplitude are greater. Nozzle spacing has a significant influence on the axial load within a narrow spacing range. As nozzle spacing increases, the axial load increases overall while the amplitude shows a decreasing trend. Particularly, when nozzle spacing exceeds a certain value, the axial load does not vary significantly.
Effect of runner tip clearance on hydraulic performance of Kaplan turbine
Authors: Shui Biao , Liu Jue , Zhan Tingjun 
Published: June 2024

Abstract
Due to its structural characteristics, the Kaplan turbine has a specific tip clearance between blade and chamber of the runner. This paper simulates effect of varied runner tip clearance on hydraulic performance of Kaplan turbine by CFD, and model tests validated the results. The results show that the efficiency and cavitation level of turbine will decrease with the increase of runner tip clearance within a specific range.
Research on Automatic Testing of Pump Turbine Model Test Based on Intelligent Technology
Authors: Han Wenfu , Gui Zhonghua , Ni Jinbing , Man Zhe , Ding Jinghua , Li Dongkuo , Wang Gang 
Published: June 2024

Abstract
In order to test the performance of pump turbine, it is necessary to collect and analyze the performance indexes such as energy characteristics, stability performance, cavitation performance and force characteristics of the unit through the pump turbine model test test system. however, the current test systems all use manual operation based on the standard specification requirements to handle the data collection and analysis of the test, and the accuracy of the data relies on human experience and the efficiency is not high. The method described in this paper uses emerging computer test technology means such as big data technology, noise and image recognition technology to automatically and efficiently complete the test data test, and quickly complete the test test, while the test results are more accurate.
Research of Key Technologies on Design and Implementation of Intelligent Pump Station
Authors: Wang Xinxin , Zhao Zhe , Li Ying , Jiang Chunge , Li Ligang , Zhou Ye 
Published: June 2024

Abstract
With the continuous advancement of technology, intelligent solutions have found widespread applications in various fields, including pump stations in water management projects. This paper focuses on the key technologies involved in intelligent pump station monitoring, control, and operation. The paper takes a pump Station as an example and addresses the problems and current situation in its management. It designs the architecture of an intelligent pump station at three layers: business application, technical methods, and requirements. Solutions are proposed for pump station dispatch and operation, safety management, and engineering maintenance. Finally, by establishing a smart monitoring system based on the five senses and one brain concept and utilizing a dual-factor intelligent verification method in conjunction with digital twin technology. Finally, intelligent management of the pump station is achieved. By exploring these technologies, the paper aims to provide insights into the crucial aspects of designing and implementing intelligent pump stations, thereby facilitating more efficient and intelligent management, control, and operation of water management projects.