bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on hump characteristics improvement of low-mid specific speed high-power centrifugal pump
Authors: Zheng Yang , Meng Long , Tian Yajuan , Wang Xin , Zhang Chiye , Chen Yuhang
Published: June 2024

The hump phenomenon is a typical hydraulic instability of centrifugal pump. The hump curve is easily found on H-Q characteristic curves of centrifugal pump at low flow conditions. Hump phenomenon causes large vibration and noise and affects the unit stability of star-up process. The impeller model with specific speed ns=100 was used an initial impeller for the high-power centrifugal pump to be developed, and the meridian flow channel keep unchanged. The impeller geometry, the blade profile, blade exit edge, wrap angle, inlet blade angle were optimized to improve hump characteristics. The 3D pump model with the initial and optimized impeller were simulated to obtain the H-Q characteristic curve. The numerical simulation results show that the inlet secondary reflux is significantly weakened, energy characteristics and hump margin of the optimized impeller are obviously improved compared with the initial impeller. The optimized impeller was also tested on the model test system to verify the hump margin. The test results demonstrate that the optimized design considerably improve the centrifugal pump’s hump margin. The results of simulations and model tests verified that impeller optimization was a suitable and efficient way to enhance the hump characteristics. The result provides design reference for long-term safe and stable operation of low-mid specific speed high-power centrifugal pump.
The Study of Using the Inducer to Improve the Cavitation Performance of a Centrifugal Pump
Authors: Ma L L , Wang C , Chen Y , Wang B H , Yu D H , Yang Y C
Published: June 2024

To improve the cavitation performance of a single-stage, single-suction centrifugal pump, this study compared the effects of an equal-pitch inducer and a variable-pitch inducer. Experimental results revealed that the NPSH3 of the pump without an inducer is 4.6m for operation at Q=80m3/h, while with an equal-pitch inducer and a variable-pitch inducer are respectively 2.6m and 2.2m. Both two inducers significantly increase the shut-off heads, while the BEP shift towards smaller flow rates, with the maximum efficiency value reduced by about 3%. The CFD simulation analysis show that when the inlet total pressure is greater than 4m, the equal-pitch inducer has better anti-cavitation performance, while the variable-pitch angle inducer has a better inhibitory effect on cavitation development which the inlet total pressure is less than 4m. To further enhance the pump’s cavitation performance, filing blade inlet suction side of the variable-pitchinducer is necessary to reduce the NPSH3 from 2.2m to 1.7m, resulting in a 22% improvement in cavitation performance.
Numerical investigation of cavitation suppression of centrifugal pump based on the bionic humpback whale blade
Authors: Wang L K , Liang C , Luo X Q , Xie H , Zhu G J , Feng J J , Li C H
Published: June 2024

Cavitation is inevitable during the operation of centrifugal pumps, it leads to the decrease in head and efficiency, and induced pressure fluctuation. This paper takes low specific speed centrifugal pump as the research object, a method of inhibiting cavitation by bionic humpback whale blade is proposed, the SST turbulence model is used to numerically study the whole flow passage of centrifugal pump. Comparative analysis of the cavitation characteristic curves under design conditions, the effects of bionic blades on water vapour volume fraction distribution, static pressure distribution, turbulent kinetic energy, vorticity field, streamline were investigated, the variation laws of cavitation morphology under different cavitation numbers is clarified. The research provides theoretical support for improving the cavitation performance and operation stability of centrifugal pump.
Numerical Study on the Hysteresis Effect of Volute Pump with Stay Vanes Based on Vortex Dynamics
Authors: Su Y Y , Wu X D , Xu B , Feng J H , Zheng T P , Liu Y Y
Published: June 2024

The hysteresis effect of volute pump with stay vanes in the hump zone can aggravate the vibration and jumping of the units, which seriously threatens the unit’s safety and stable operation. The formation mechanism of the hysteresis effect in hump zone is analyzed by carrying out unsteady numerical simulation of the volute pump with stay vanes at medium-low specific speed based on vortex dynamics theory. The results show that hysteresis effect occurs in volute pump, the fluid inertia force in FID is smaller than that in FDD, and the fluid viscous force in FID is larger than that in FDD. The hysteresis effect is not only related to the Karman vortex generated by the flow separation of vane and guide vane, but also closely related to the stall vortex generated in the volute. This work may provide a guide way for the optimal design and stable operation of the volute pump with stay vanes.
Research and Application of Key Technologies for Ultra High Pressure Grouting of Yangjiang Pumped Storage Power Station in Guangdong Province
Authors: Shi Yunli , Liu Xueshan , Huang Yufei , Zheng Yueyang , Wang Yuezhi
Published: June 2024

The most effective guarantee measure for the permeability stability of reinforced concrete lined high-pressure waterways is grouting. The traditional grouting treatment techniques and specifications can not effectively adapt to construction projects with higher requirements. This paper comprehensively expounds the new theoretical research system and grouting engineering design method proposed through model test and inverse calculation, and introduces the construction technology and technical requirements of 10Mpa ultra-high pressure grouting in the engineering field in combination with the construction practice of Yangjiang Pumped Storage Power Station, so as to provide useful reference for the construction of high-pressure waterway of pumped storage power station project.
The layout design of water diversion system in Zhaoqing Langjiang Pumped Storage Power Station based on front well drill method
Authors: Jingwei Sun , Han Wu , Lu Zhao , Yan Shi
Published: June 2024

The water diversion system of pumped storage power station is usually the subcritical line of engineering construction progress. It is easy to develop into a critical line due to the influence of uncertain factors in the construction process. In order to further ensure the construction progress of the project, the water diversion system of Zhaoqing Langjiang Pumped Storage Power Station was planned to adopt the fast front well drill construction method in the mining industry. In order to adapt to the construction technology of front well drill construction method, the layout design of the water diversion system was studied and optimized by considering the topography and geology, engineering layout, hydraulics, construction organization and other aspects. Finally, the appropriate layout scheme of water diversion system was drawn up.
Analysis of OWC impulse turbine flow characteristics considering the blade tip clearance
Authors: Jiajie Liu , Yexiang Xiao , Jie Liu , Hao Lin , Haijun Li , Qingpin Du
Published: June 2024

Oscillating water column (OWC) ocean wave energy recovery device is a popular technology in current wave energy research, which possesses the advantages of a sturdy structure and low-maintenance requirements. The device recovers energy by unidirectional rotation in the reciprocating airflow generated by an impulse turbine. Its operational performance depends on the flow efficiency of the core component, the air turbine. In this paper, a prototype impulse turbine with blades tip clearance of 1 mm was considered, and the SST k-ω turbulence model is used to calculate the operating performance of the air turbine at different operating points. The calculation result shows that the efficiency of the turbine under the optimal operating conditions is about 51.41%. When the flow coefficient is less than 0.8, the primary focus of energy loss in the rotor occurs at the blade tip. The low flow rate leads to a high inlet angle causing fluid friction. In these small flow conditions, the pressure drop at the leaf top gap is cantered on the inlet, and the speed in the gap flow field is significantly reduced. When the flow coefficient is greater than 1.4, the concentration of energy loss in the rotor primarily occurs within the flow channel, where the high-velocity air causing a local high-speed zone.
Investigation on hydraulic characteristics of a model and prototype bulb turbine based on similarity criteria
Authors: Zhou Xuezhi , Luo Yongyao , Wang Zhengwei , Ahn Soohwang , Luo Hongyun , Wu Yibin , Zhou Jingming
Published: June 2024

From the perspective of the world hydropower utilization trend, the medium and high head hydraulic resources are gradually decreasing, and along with much more attention to the ecological environment and land resource constraints, low-head hydropower plants have been becoming particularly prevalent. Benefit from compact structure, less investment, high capacity and wide operation range, bulb tubular turbines have come up to be the optimal option for the development and exploitation of low-head energy resources and been widely applied. In this paper, based on measurement data and CFD simulation results of model and prototype, scale effect which derived from similarity law was picked up to investigate the hydraulic performance and operating properties. Through comparison and analysis, it’s concluded that distinct from high-head application similarity conversion turns out to be more complicated for bulb turbines in case of flow characteristics, and it’s recommended that this conversion be further modified considering different boundary conditions. Such achievements will be of great help to look into the mechanism of ratio effect and accelerate research progress.
Technical Characteristics and Application Introduction of Horizontal Shaft Francis Double Runner Hydro Turbine Unit
Authors: Kuang Ding , Zujia Chen
Published: June 2024

Horizontal shaft Francis turbine generator units are widely used in small hydropower stations due to their simple structure, small civil engineering quantities, and convenient daily maintenance. However, some hydropower stations with large flow variation have certain problems with the stability of turbine operation under low load and small flow conditions. To adapt to large flow variation, increasing the number of units and reducing the unit capacity will significantly increase project investment, this paper introduces a horizontal shaft Francis double runner type hydro turbine unit, which has a wider power range for stable operation and a larger applicable flow variation, providing a new idea for the selection of small hydro turbine units with large flow variation.
Quantitative analysis on influence factors of power response rapidity of pumped storage units
Authors: Chen Jingdan , Yang Weijia , Li Yulan , Liao Yiwen , Huang Yifan , Qian Yiming , Chen Qiao
Published: June 2024

The rapidity of power response in pumped storage units (PSUs) plays a crucial role in their regulating performance within power grids. Consequently, it is essential to conduct a quantitative analysis of the power response power response rapidity. A numerical simulation method is adopted to investigate the fastest power response of PSUs and the corresponding response conditions. By considering two real power plants in China as case studies, the influence of characteristics of control and hydraulic systems on the power response rapidity is examined. In addition, by giving six different power commands, the fastest response of PSUs under the influence of multivariate coupling is explored. The findings reveal that the maximum power response rates of the two plants are 8.361%/s and 11.848%/s respectively in this work. The quantitative analysis can provide a reference for the fast power response and parameter optimization of pumped storage plants.
Selection of rated head of a pumped storage power station
Authors: Zhao Long , Cheng Yanan , Wang Jue
Published: June 2024

Rated water head is one of the important parameters of pumped storage power station, which is of great significance to the safe and stable operation of the power station. However, at present, there is no unified regulation on the selection of rated head of pumped storage power stations at home and abroad. Based on the relevant technical documents and selection standards, combined with the unit manufacturing, stable operation, kinetic energy utilization, project investment and other aspects of specific projects, we finally conclude the rated head recommendation scheme of the power station, which can provide a certain reference for similar pumped storage power stations.
Influence of different turbulence models on tip vortex prediction
Authors: Fang Mingkun , Li Na , Tao Ran , Xiao Ruofu
Published: June 2024

Tip vortex cavitation usually occurs in marine propellers and axial-flow turbines, the cavitation in the tip vortex could potentially result in blade erosion, at the same time, it will cause the pump vibration and noise emission. The tip vortex mainly occurs in rotating machinery with complex three-dimensional flow, but the prediction of the hydrofoil tip vortex can provide a basis for the study of the blade tip vortex in rotating machinery by simplifying the blade model. Hence, in this paper, we use the commercial software CFX to investigate the impact of distinct turbulence models on the configuration of tip vortex distribution in the NACA 16-020 hydrofoil, including SST (Shear Stress Transport), DES (Detached Eddy Simulation), LES (Large Eddy Simulation) turbulence models which are widely used in the field of rotating machinery. At the same time, the axial and radial velocity distributions at different locations downstream of the tip of the hydrofoil are compared to analyse the effects on the velocity distribution near the vortex core line stemming from various turbulence models. By comparing with the experimental data, the most accurate turbulence model for tip vortex prediction is obtained, which will provide guidance for the next step tip vortex prediction and the control of tip vortex flow.
On the validation of the cavitation model considering the thermodynamic effect of cavitating flow
Authors: Yu Lu , Geng Da , Liu Xin , Liu Shuhong , Zuo Zhigang , Zeng Chongji , Li Hui
Published: June 2024

It is known that when choosing water as a substitution of liquid hydrogen and liquid oxygen for cavitation investigations, the influence of thermodynamic effect should not be ignored. However, due to the lack of systematic experiments, most existing simulating studies use the average dynamic characteristics obtained earlier in 1970s for simulation validation, which may not be effectively accurate. In this paper, the unsteady experimental observations of cavitating flow on flat plate hydrofoil are presented in detail with the help of the advanced water tunnel in Tsinghua University, which is conducted in 2020s. Then the effectiveness of the numerical method considering the influence of thermodynamic effect is further verified with these dynamic observations. Results show that the method is effective and reliable, capturing the main features of the cavitating flow. And it can be used to simulate the cavitating flow considering the influence of thermal effect in the future.
The influence of structure parameters on the pressure characteristics of spillway tunnel
Authors: Funan Chen , Xiaoying Huang , Yang Xue , Gaohui Li , Weijie Cui
Published: June 2024

Cavitation is one of the key challenges of high-head and large-discharge spillway tunnel. The high-speed flow may cause a sudden drop in pressure in the case that spillway tunnel built without suitable shape or smooth surface. Meanwhile, the complex flow pattern accelerates the occurrence of cavitation. The anti-arc section is usually set at the end of spillway tunnel for trajectory bucket type energy dissipation, and a horizontal section may be set upstream of the anti-arc section to adapt to local topography. It’s necessary to conduct in-depth research on the pressure characteristics of horizontal section and anti-arc section to prevent cavitation. In this paper, the pressure distribution along the spillway tunnel is calculated using VOF method. The influences of the length of horizontal section, the radius of anti-arc section and arc section are studied. The results show that the horizontal section suffers low pressure. Reducing the radius of anti-arc section is effective for raising the pressure in horizontal section. However, the minimum pressure cannot be raised when the length is larger than a certain value.
Simulation of the Effect of Particle-bubble Size Ratio on the Collapsing Dynamics of a Cavitation Bubble Near a Particle
Authors: Zhang H , Dai Y , Yang J Q , Chen T
Published: June 2024

The synergistic effect of cavitation bubbles and sediment particles on material damage is a significant problem in fluid machinery. The dynamic behavior of a cavitation bubble near a spherical particle were simulated in this study using the Volume of Fluid (VOF) method. The effects of the particle-bubble size ratio δ on the bubble profiles, the collapse time, the micro-jets and the pressure at the particle surface have been investigated under the conditions of three values of stand-off distance γ. The results show that (1) the bubble collapse time rises as the particle-bubble size ratio δ increases; (2) the peak values of the maximum jet velocity and the maximum pressure exerting on the particle appear at γ = 1.0 and δ = 1.2, which are 165.3 m/s and 10.46 MPa, respectively; (3) the influence on the particle caused by the micro-jets cannot be ignored when the stand-off distance is less than 1.5.
Effect of structural parameters of biomimetic jellyfish on propulsive performance
Authors: Miao Xingyu , Liu Jinzhe , Li Kailin , Zhang Ruihan , Gao Li
Published: June 2024

Based on numerical simulation technology, the dynamics simulation of a two-dimensional jellyfish model was carried out. The study analyzed the changes in the surrounding flow field with variations in the jellyfish’s shape during its biomimetic movement. Additionally, it explored the impact of parameters such as the head-body ratio and the ratio of open-close time on the propulsion performance of the biomimetic jellyfish. The research findings revealed that reducing the head-body ratio and increasing the ratio of open-close time improved the propulsion performance of the jellyfish. Specifically, decreasing the head-body ratio resulted in a greater increase in thrust, while increasing the ratio of open-close time led to a smaller enhancement in thrust.
The dynamical response of turbulent flow to bed deformation under submerged discharge and plane vertical impinging jets
Authors: Tingting Liao , Huating Xu
Published: June 2024

On the conditions of discharge under sluice gate and vertical jets, the research on the dynamical response of hydraulic elements to bed deformation is much concerned in the field of high-speed flow and hydraulic dredging but not be solved yet. Research achievement from numerical simulation are drawn as follows: (1) Under sluice gate discharge condition, the response of hydraulic elements to bed deformation is that the bed is deforming in the direction of the mechanical energy loss, the rate of the bed deformation and the mechanical energy loss near the local scour hole and the horizontal distance from the reattachment point to the maximum scour depth are all continuously varying with the scouring of time and synchronously approaching to its own certain value. (2) Under vertical jets discharge condition, the response of hydraulic elements to bed deformation is that the rate of bed deformation and the pressure of the maximum scour depth is monotonous continuously decreasing with the scouring of time and synchronously approaching to its own certain value.
Numerical simulation of sand erosion in Venturi tube under different flow characteristics and sand content
Authors: Pan Jiale , Guang Weilong , Liu Qiang , Lu Jiahao , Tao Ran , Zhu Di , Xiao Ruofu
Published: June 2024

In the solid-liquid two-phase flow, there is flow erosion of solid relative to the surrounding wall or other components, which has attracted the attention of many scholars. Wherever flows are involved, erosion tends to be a problem. Especially in rivers with large sediment content, hydraulic machinery including pumps, water turbines, reversible water pump turbines and pipelines in a long time of flow erosion, it is easy to cause the material damage of the flow parts, affect the head and efficiency to a certain extent, may also lead to the increase of the gap between the flow parts resulting in noise and other hazards. However, in different flow conditions, the location of erosion is different, which makes it difficult to prevent erosion. As a common measuring tool, Venturi tube has a certain representative geometric shape. The erosion prediction of Venturi tube by computational fluid dynamics can provide a certain reference for other structures. In this study, the solid-liquid two-phase flow analysis method based on CFD was used to analyze the flow erosion under different velocity and sediment content. Through numerical simulation, it is found that the erosion problem in Venturi tube is closely related to its flow characteristics.
Research on contact stiffness of tenon jointed turbine bladed disk under time-varying load
Authors: Qu Zhen , Yao Can , Honglai Zhu , Lin Xingrong , Chen Lei , Hu Heran
Published: June 2024

Tenon-jointed turbine blades will be impacted by airflow and centrifugal force during the high-speed rotation of the engine. The surface contact stiffness of the tenon and tenon groove will change with complex external loads. Through the analysis of the micro-morphological characteristics of the contact surface of the tenon joint bladed disk, the contact characteristics of the asperities on the rough surface are determined. At the same time, to solve the problem that the traditional microscopic contact stiffness calculation formula cannot be applied to the tangential displacement load, the periodic piecewise tangential stiffness expression is derived based on external loads of the normal force and the equivalent tangential force. Furthermore, this paper studies the properties of the tangential stiffness curves under different external load frequency ratios and phase differences. An increase in the frequency ratio will decrease the step value of the piecewise function and make it tend to a smooth transition. The change of the phase difference will directly change the monotonicity and fluctuation of the stiffness curve. The macro and micro theoretical analysis methods of contact characteristics have been established.
Numerical simulation analysis and experimental verification of air flow measurement in large-diameter S-shaped pipe
Authors: Jia Lu , Zeng Yongzhong , Liu Xiaobing , Yu Zhishun
Published: June 2024

The ventilation systems in nuclear power plants, hydropower plants, and other large-scale projects involve the transportation of fluids through large-scale pipelines. To achieve a more stable flow velocity distribution, the fluid needs to pass through a straight pipe section of sufficient length upon entering the pipe. Typically, this straight pipe section should be at least 15 times the inner diameter of the pipe. However, for large-diameter irregular square pipes with a diameter exceeding 1m, where the curved section is short and there are no long straight pipe sections before and after it, the flow field inside the pipe becomes complex, requiring accurate measurement of the flow rate.In this regard, a numerical simulation analysis is conducted to address this challenge. A mean velocity evaluation method based on the coefficient of variation is proposed. This method identifies multiple points within the pipe that best represent the average flow velocity, determining the insertion depth of sensors and the weight coefficients of these multiple measuring points. A calculation formula is derived, utilizing the cross-sectional average velocity as a function with the velocity values at multiple points in the flow field as independent variables. To validate the accuracy of the proposed method, flow measurement experiments are performed on a wind tunnel test bench. The calculated values obtained from the derived formula through numerical analysis are compared with the experimental results. The relative error within the full range is found to be less than 0.54%, confirming the accuracy of the formula. The research findings present a novel measurement method for airflow in large-diameter irregular square pipes and offer valuable practical insights for engineering applications.
Study of the Measurement Method on the Dynamic Stress and Pressure of Model Pump-turbine Splitter Blades
Authors: Yingnan Zhao , Xiaolong Yang , Huanmao Wang , Kai Lin , Jinwei Zhang , Xingchun Lei , Yue Zhao , Wei Zhao
Published: June 2024

The operation conditions of the pump-turbine are changed frequently and are worse than the conventional turbine. The operation stability of the pump-turbine is more focused with the incremental unit capacity and the pump-turbine runner diameter. The research of the measurement method for the dynamic stress and the pressure of the model pump-turbine splitter runner blades is performed to evaluate the stress and pressure distribution under the various operation conditions, it is optimized for the turbine mechanical and hydraulic computation, the operation references are provided for the prototype pump-turbine also. In this paper, the measurement positions of the blades are determined based on the hydraulic CFD and mechanical computation, the measurement method of dynamic stress and pressure of model pump turbine-runner splitter blades is studied.
Research on the Digital Maintenance Construction of Hydropower Unit
Authors: Chen Tiehua , Pan Yu , Liu Xinze , Wu Guangxin , Xu Ming
Published: June 2024

At present, the single unit capacity of hydropower unit is increasing, and the problems of difficulty, high precision, large number of labors and high cost in the maintenance process of large unit are becoming increasingly prominent. With the proposal of intelligent construction of hydropower plant, digital maintenance of hydropower unit has become a research hotspot. This article proposes a construction idea for a digitized maintenance system for hydraulic units based on technologies such as RFID, IoT, and artificial intelligence. This system can modularly manage the unit components and realize the integration and interaction of unit maintenance information through the visualization platform. It utilizes IoT sensors to collect comprehensive information on the components involved in the maintenance process. The components’ information is managed in a hierarchical manner using device KKS coding and a hierarchical structure diagram of the hydraulic unit’s equipment components. Through a visualization platform and equipment knowledge base, the component information is processed and analyzed to generate optimal assembly sequences and paths, thus improving the scientific and rational aspects of the unit’s maintenance process. This approach provides theoretical support for maintenance operations and enhances overall work efficiency.
Research on fault diagnosis of main equipment based on watershed power production data center
Authors: Kang Zhuo , Xiaoyi Chen , Wei Zheng , Linli Song , Peng Zhang , Fatai Shi , Dongjun Wu , Yuting Guo
Published: June 2024

With the development of intelligent hydroelectric power stations and centralized control centers, water and hydropower development companies in various river basins have constructed power production data centers, establishing standardized and normalized data models and connecting the underlying system channels. Based on the power production data center, this paper constructs a unified data model for monitoring the main equipment and, in response to the shortcomings of the existing equipment alarm mode, analyzes the advantages of expert knowledge and intelligent diagnostic methods. It establishes a comprehensive diagnostic system for the main equipment of power stations, providing multi-level and multi-perspective diagnostic reference opinions. This system is of great significance for promoting the development of intelligent hydroelectric power and centralized control. Finally, taking the operating condition data of a mixed-flow turbine generator unit as an example, the effectiveness of the comprehensive diagnostic model is analyzed and verified.
Research on the capacity allocation of composite energy storage systems for hybrid ships
Authors: Tian Fengchao , Sun Jun , Wang Xing
Published: June 2024

Aiming at the problem of unstable output power fluctuation of the dredger during operation, a composite energy storage system consisting of lithium iron phosphate battery and supercapacitor is introduced to smooth out the power fluctuation. Considering the configuration cost, operation and maintenance cost of the energy storage system, the capacity optimization model of the composite energy storage system is established with the average daily cost as the objective function, and with the system power balance, the charge state of the energy storage system, and the rated power as the constraints. The optimal capacity is solved by using the modified artificial fish swarm algorithm (MAFSA). The final results show that MAFSA reduces the capacity of the battery and the supercapacitor by 6.9% and 9.9%, respectively, and reduces the average daily cost of the system by 13.5%. Meanwhile, the capacity-optimized energy storage system enables the generator set to work in the optimal operating range, which reduces its output power fluctuation, improves its efficiency, and reduces fuel consumption and pollutant emission.
Design of downhole oil-water separation device and study on separation mechanism based on rod pump heavy oil system
Authors: Yan Yongheng
Published: June 2024

Downhole oil-water separation technology (DOWS) is a new type of separation technology, which can improve efficiency, reduce energy consumption, and can solve the problem of high water cut oilfield development. At present, there are only two separation methods in the same well injection-production separator, one is the swirl separation technology and the other is the gravity separation technology. Cyclone separation technology mainly relies on cyclone separators to separate oil and water, but it is affected by oil viscosity, water content, and temperature. The gravity separation technology mainly relies on the similar separation principle of a multi-cup equal-flow gas anchor to design a multi-cup equal-flow oil-water separator, but it requires the oil-water mixed production liquid to stay in the settling bowl for a long time. The centrifugal separator has the characteristics of a good separation effect, high efficiency, and low demand for oil. At present, the downhole centrifugal separator is not used in the same well injection-production technology, which mainly needs to solve the driving force problem of the centrifugal separator. The new injection-production device designed in this paper can better solve the driving problem of the centrifugal separator and meet the working requirements of the process.
Capacity optimum distribution mode of various types of energy storage devices considering the improvement of active-supporting capability
Authors: Wang Feng , Zhang Tao , Zhao Feng , Tian Pengfei , Ma Zhiyong
Published: June 2024

Under the dual-carbon development goal, the energy storage (ES) demand on the new energy (NE) side has been upgraded from the scene of promoting absorb to the scene of promoting absorb and actively supporting the power grid. Therefore, this paper proposes a capacity optimum distribution mode (CODM) for various types of ES equipment considering the improvement of active-supporting capability. Firstly, a polytypic ES capacity optimum distribution method considering both NE absorb and active-supporting grid capacity improvement is proposed. Then, the solution process of the complex model is optimized by introducing the characteristic curve extraction method of typical working conditions. Finally, founded on the historical data of typical NE power stations, the ES configuration requirements and economy under the scenes of promoting absorb, promoting absorb and active-supporting are calculated. The comparison results show that compared with promoting absorb, the scenes of promoting absorb and active-supporting can better meet the ES requirements of the NE side technically and have a better economy.
Oxygen reduction reaction activity of Co3O4-modified Pt-graphene electrocatalysts
Authors: Liu Hangcheng , Tao Zeyu , Liu Jianfeng , Shi Zhengrong
Published: June 2024

In this paper, the ORR activity of Pt/Co3O4-modified N-doped graphene electrocatalysts was investigated based on DFT theory. The Dmol3 module in Materials Studio software was used to optimize the construction of NG models under different doping conditions and to calculate the adsorption and desorption properties of oxygen molecules by optimizing the conformation of Pt13 clusters and substrates. A comparative analysis revealed that the Co3O4 modification reduced the oxygen adsorption energy of the Pt/G catalyst. However, after N doping, the oxygen adsorption energy of Pt/Co3O4/NG was superior to that of Pt/NG. After theoretical analysis, it was determined that it was because the doping of N atoms in graphene could promote the release of oxygen vacancies in Co3O4 and strengthen the adsorption interaction between Pt and graphene carriers to improve the oxygen adsorption energy.
Analysis of bending and torsional modal of PMSM rotor systems for EV
Authors: Wang Xiaoxiao , Li Quanfeng
Published: June 2024

The rotor system is crucial in the all-in-one integrated power system of EV, making the study of its dynamic mechanical performance at high speeds imperative. This paper focuses on analyzing the modal characteristics of EV rotor systems and the impact of individual components on bending and torsional vibrations. Using finite element analysis (FEA), a modal analysis of a 100 kW high-speed electric motor rotor is conducted, followed by experimental tests using an exciting method. Comparing simulation with experimental results reveals how end caps and bearings reduce the rotor’s bending natural frequency (BNF), while the core increases it. Additionally, the addition of rotor components leads to varied reductions in the rotor’s torsional natural frequency (TNF). Furthermore, the error between FEA and experimental values for combined rotor modes remains within 3.53%, affirming the accuracy and reliability of the analysis in predicting rotor modal characteristics.
Experimental study of heat transfer performance of industrial air cooler applying R449A instead of R507A refrigerant
Authors: Peng Haowei
Published: June 2024

In response to the problem of refrigerant pollution of the environment, this paper carries out research experiments on the performance of industrial air coolers using R449A and R507A refrigerants, comparing how refrigerant properties impact evaporator heat transfer performance. The parameters, such as the cooling capacity of the evaporator, were analyzed using the heat balance method. The results demonstrate that using R449A refrigerant in the evaporator at 0 °C enhances cooling capacity by 4.52% and heat transfer coefficient by 9.1% compared to the original R507A system. Using R449A refrigerant in the evaporator decreased the cooling capacity and heat transfer coefficient by 25% and 28.26%, respectively, at -18 °C, compared to the original R507A system. Studies have shown that R449A, when replacing R507A systems, has better heat transfer performance at higher temperatures and is suitable for refrigeration systems with higher temperature conditions.
Electrification reconstruction design and analysis of the coal-to-ethylene glycol process
Authors: Wang Dongliang , Wu Bo
Published: June 2024

Industrial electrification is an important way to reduce greenhouse gas emissions and address the issue of renewable energy consumption. Using coal-to-ethylene glycol as an example, the methodology and techno-economic analysis of integrating renewable energy sources with the chemical industry are examined. The findings demonstrate that if electricity prices decline, a reconfiguring electrification process for coal-to-ethylene glycol that uses renewable energy can lower CO2 emissions by 90.88%, boost energy efficiency by 2.21%, and result in cost savings. The electrification reconstruction in chemical industry can aid in the energy transition.
Analysis and optimization of circulating cooling technology of super heavy oil steam spray
Authors: Suen Sen , Yang Hanhua , Ma Dawen , Li Xuejun , Wu Dihua , Lan Mingju , Xiong Xiaoqin
Published: June 2024

The circulating cooling technology of super heavy oil steam spray is crucial for efficient oil vapor (gas) separation in closed transfer station processes and is a key factor in energy consumption within the gathering and transportation system. Therefore, the analysis and optimization of this technology are particularly important. This study analyzed the process of super heavy oil steam spray circulating cooling technology using ASPENPLUS and established a nonlinear integer optimization model to minimize electricity consumption, utilizing Python for programming and the ipopt solver for resolution. It was found that the temperature and flow rate of the steam entering the spray tower affect the flow rate of the exported condensate water, thereby impacting energy consumption. Optimizing the number of operational air coolers can achieve the purpose of energy saving.
Research on the expansion scale of hydropower station installed capacity during deep development
Authors: Wang Fei , Wang Wei , Li Qilong , Xu Da , Yu Jialiang
Published: June 2024

In order to alleviate the problem of global warming, achieve the national goal of carbon emission reduction, and meet the need to increase peak shaving pressure on the power grid because of wind power and solar energy, hydropower resources will turn to in-depth development. This paper analyzes the methods for determining the scale of deep hydropower development from the perspectives of power system demand and hydropower resource utilization. From the perspective of the power system demand, this paper analyzes the reasonable utilization hours of hydroelectric installed capacity in a power grid, optimization methods for power structure, and deep development scale analysis methods. From the perspective of hydropower utilization, this paper analyzes the supplementary installed capacity utilization hours, reasonable installed capacity and guaranteed output ratio of a single hydropower station, and the economic scale calculation method for deep development. This provides a reference for the subsequent deep development of hydropower stations.
Selection of household heating equipment: A case study of Lianyungang city
Authors: Yang Zhenming , Wang Shuai , Zhao Yulei
Published: June 2024

Based on the local climate in Lianyungang, this paper analyzes the local heating demand, a comprehensive comparison of mainstream heating equipment and terminal forms, and analysis and discussion, respectively. By simulating the heating situation in Lianyungang in winter, the heating cost of different equipment in Lianyungang in winter is calculated and combined with the operation of existing projects, and the differences in cost, use, installation, and maintenance of different heating equipment are compared. Finally, the most suitable heating form for Lianyungang users is summarized by integrating theoretical data and actual situations.
Research on internal flow characteristics of the planar conical tube for valveless piezoelectric micropump
Authors: Cai Shengchuan , Wen Xueying , Dong Min
Published: June 2024

As the most commonly used driving and executing components in microfluidic systems, valveless piezoelectric micropumps have broad application prospects in numerous fields. The steady and unsteady characteristics of planar conical tubes for valveless piezoelectric micropumps were simulated using CFX software at different pressure amplitudes and driving frequencies. The aim was to obtain the factors affecting the flow performance of the valveless piezoelectric micropump. The results show that the numbers of Remax
in both diffusion and contraction directions of the planar conical tube increase with increasing pressure. When the number of Wo is lower, the number of Remax
under a steady state is approximately equal to that under an unsteady state, and the maximum relative deviation is only 0.25%. The greater the Wo number, the smaller the velocity on the minimum flow section, and the more significant the velocity change. The rectification efficiency η of the valveless piezoelectric micropump and the efficiency λ of the planar conical tube both increase with increasing pressure under steady conditions, and the maximum values can be reached at 11.2% and 1.56, respectively.
Optimization study on the configuration of electric hydrogen bidirectional coupling microgrid considering system flexibility margin
Authors: Li Yuanxun , Zhang Liting , Li Qifen , Yang Yongwen
Published: June 2024

The solution to the global environmental concerns lies in the clean transformation of the energy system. However, the rapid expansion of renewable energy has increased the dangers of the power grid’s reliable functioning. It is vital to look into more controllable and flexible resources to increase the power grid’s capacity for regulation. Therefore, this paper provides an optimization model for a microgrid that couples electricity and hydrogen, which can improve the flexibility margin of the system significantly through bidirectional transformation and complementarity of electricity and hydrogen. The capacity configuration of each device in the system is solved to optimize the net profit of the system over the course of the system’s life cycle based on the forecast of the demand for wind and solar power generating output and load in the near future. A rolling scheduling simulation is run within a day to optimize the system capacity configuration with the goal of reducing daily operating expenses and maximizing flexibility margins. The results show that the electric-hydrogen coupled system can guarantee the absorption of 100% renewable energy of the traditional electric storage system, which improves the flexibility of the system by 410% and the benefit by 55.6%. This study offers recommendations and resources for the creation of flexible planning for the microgrid system with electro-hydrogen connection.
Distributed photovoltaic hosting capacity assessment technology considering stable operation of distribution network
Authors: Zheng Qiangren , Wu Ming , Hu Lijuan , Li Baoju , Wang Yunhui , Guo Miao , Zheng Nan
Published: June 2024

The rise of distributed photovoltaic (PV) in recent years has enhanced the sustainability, reliability, and flexibility of power systems. However, excessive PV access beyond the distribution network’s hosting capacity can jeopardize grid security and stability. This paper proposes a data-driven assessment method for PV carrying capacity, ensuring optimal integration while considering operational stability. Detailed analysis of a specific distribution network validates the method’s efficacy, leveraging network data for accurate evaluation. The approach holds promise for widespread adoption and large-scale application.
A novel digital energy computation method for dynamic reconfigurable battery networks
Authors: Zhang Congjia , Lei Ertao , Zhou Yanglin , Zhang Junkun , Quan Yue , Ci Song
Published: June 2024

Dynamic reconfigurable battery network (DRBN) is a promising method to overcome battery imbalance. As a complement, a battery management system (BMS) plays a key role in battery status estimation, battery topology reconfiguration, and thermal management. Different from the traditional BMS, a fully distributed DRBN control framework requires high efficiency and massive computation. Inspired by the computer architecture, we propose a novel digital energy computation method for DRBN. First, according to the first principle, we apply the idea of shielding terminal differences on the Internet to BESSs. Then, based on time-oriented management, the framework of DRBN is introduced to eliminate battery differences. Finally, a case analysis shows that DRBN can effectively realize battery balancing during the charging process.
Photoelectric properties of CsPbBr3 perovskite solar cells based on amorphous Nb2O5 electron transport layer
Authors: Zhu Kun , Fu Liyou
Published: June 2024

The superior air and temperature stability and the cheap production costs of the inorganic CsPbBr3 solar cell (PSC) were major concerns. For inorganic CsPbBr3 devices, TiO2 crystals (c-TiO2) are frequently used as an electronic transfer layer (ETL). However, because c-TiO2 preparation necessitates temperatures over 450°C, the flexible inorganic device CsPbBr3 cannot be used. In addition, the low mobility of electrons further limits the ability to improve device performance. On this basis, a novel amorphous Nb2O5 (a-Nb2O5) was prepared. This paper introduces a simple method of preparing inorganic planar CsPbBr3 devices by room temperature sputtering. The highest efficiency of PSC prepared with a-Nb2O5 ETL was 5.74%, which was higher than that of crystalline Nb2O5 (a-Nb2O5) or crystalline TiO2 (c-TiO2) based PSC (5.12% or 4.67%). The photovoltaic properties of CsPbBr3 PSC prepared by a-Nb2O5 ETL were improved. The causes might be attributed to the following: excellent crystallization of the films made from a-Nb2O5 and CsPbBr3, low charge recombination rate of the a-Nb2O5/CsPbBr3 interface, strong optical transmission, and appropriate operating function of a-Nb2O5. In addition, PSC CsPbBr3 based on unpackaged a-Nb2O5 has good long-term stability in the atmosphere. This work offers a fresh line of inquiry for producing extremely effective inorganic PSC.
An energy management strategy for thermoelectric power generation system
Authors: Liang Yanqin , Wang Ying , Wang Jianjun
Published: June 2024

To enhance the output power of thermoelectric generation, a strategy for the energy control of the thermoelectric power generation system is proposed, which involves the rational control and allocation of its output energy. The system includes a thermoelectric battery, DCDC converter, controller, storage battery, and DC load. The system completes energy control based on the relationship between the power generation and load power. The system adopts the maximum power point tracking (MPPT) algorithm, which obtains the maximum output power of the thermoelectric battery by changing the duty cycle of the converter, thus improving the output power and working efficiency of the thermoelectric power generation system. To protect the storage battery and extend its service life, the system adopts a charging management method that combines MPPT charging, constant current charging, and constant voltage charging, making it more scientific and reasonable. Finally, the feasibility and effectiveness of the proposed energy control management strategy are verified through actual experimental results.