Design Of Power Stations Research Articles

Analysis of safety margin for pump-turbine “S” characteristics of Pumped-storage Power Stations

Abstract The pump-turbine is the “heart” of Pumped-storage Power Stations, and the “S” characteristics is an inherent characteristic of the routine Francis pump-turbine unit, which is an important factor affecting the safe and stable operation of the unit. There are three main methods for conducting research on the “S” characteristics: model testing, on-site testing, and CFD numerical simulation calculation. Based on the theoretical research of CFD numerical simulation calculation, this article compares and analyzes the results of model testing and on-site testing for specific practical cases, studies the differences between these two methods, and provides suggestions for the reasonable value of safety margin in the “S” area of the pump-turbine based on engineering practice, providing reference for the design of new or renovated power stations and the hydraulic optimization of pump-turbines.

A Theoretical Analysis of Meteorological Data as a Road towards Optimizing Wind Energy Generation

The development of wind energy has been observed for many years. Both construction firms and the scientific world are analyzing new design solutions, atmospheric conditions and the technical performance achieved. The main goal of this research is to evaluate the requirements that have to be met to design wind power stations that would be an optimal fit for the climatic conditions in Poland. This study combines the results of empirical studies on wind velocity distributions with the physical fundamentals of wind power station design. This paper presents modelling of the relationships between wind velocity distributions observed in Poland and technical requirements for wind power stations design. The wind velocities distributions for various locations in Poland are determined and expressed in Weibull distribution parameters. Theoretical computations concerning the dependence of wind power stations as function of wind speed and air’s physical properties are presented. Conclusions important for the design of power stations fitted to the atmospheric conditions in Poland are given. LabVIEW 2021 was used for computer modeling.

Study of intermittent jets and free-surface-pressurized flow in large hydropower tailrace tunnel

The tailrace tunnel system, as a core component of hydroelectric power stations, directly influences the stability and efficiency of the power generation process. Transient conditions often lead to the occurrence of complex unsteady flow phenomena in the tailrace tunnel. In this study, numerical methods integrating open channel flow, multiphase flow, and compressible models were combined to conduct hydraulic analysis of the tailrace system in large hydroelectric power stations. Under specific conditions, periodic jet phenomena were observed, corroborating field observations. The research revealed that the proximity of downstream water levels to the crest level of the tailrace outlet is a prerequisite for the periodic jetting phenomenon, with a sudden rise in water level serving as a triggering condition. Although the surge shaft effectively mitigates wave action, it fails to entirely eliminate the influence of pressure pulsations, resulting in a 23.2% increase in pressure pulsation amplitude in the turbine area. However, the efficiency of the turbine unit is hardly affected; only a slight loss of energy occurs due to the increase in local turbulent entropy production, deemed inconsequential for the overall system. This study aims to investigate the complex response of tailrace tunnel systems in hydroelectric power generation amidst abrupt changes in downstream river, providing crucial insights for the engineering design and operation of large-scale power stations.

A Symmetric Sixth-Order Step-Up Converter with Asymmetric PWM Achieved with Small Energy Storage Components

This research explores an improved operation of a recently studied converter, the so-called two-phase sixth-order boost converter (2P6OBC). The converter consists of a symmetric design of power stations followed by an LC filter; its improved operation incorporates an asymmetric pulse width modulation (PWM) scheme for transistor switching, sometimes known as an interleaved PWM approach. The new operation leads to improved performance for the 2P6OBC. Along with studying the 2P6OBC, one of the contributions of this research is providing design equations for the converter and comparing it versus the interleaved (or multiphase) boost converter, known for its competitiveness and advantages; the single-phase boost topology was also included in the comparison. The comparison consisted of a design scenario where all converters must achieve the same power conversion with an established maximum switching ripple, and then the stored energy in passive components is compared. Although the 2P6OBC requires a greater number of components, the total amount of stored energy is smaller. It is known that the stored energy is related to the size of the passive components. Still, the article includes a discussion of this topic. The new operation of the converter offers more streamlined, cost-effective, and efficient alternatives for a range of applications within power electronics. The final design of the 2P6OBC required only 68% of the stored energy in inductors compared to the multiphase boost converter, and 60% of the stored energy in capacitors. This result is outstanding, considering that the multiphase boost converter is a very competitive topology. Experimental results are provided to validate the proposed concept.

Tri-Loop design and thermoeconomic analysis for the high temperature gas cooled nuclear reactor coupling energy storage system

Thermal energy storage is a proposed solution that enables nuclear power plants to adjust their output without altering power levels. This technology manages fluctuations in the power generation process by storing generated heat above demand levels until it is required to produce steam. Despite the initial investment needed for infrastructure construction, these costs are easily offset by the ultimate returns, especially when efficiency is improved to 85% to 90%. In the context of nuclear power plant applications, helium molten salt energy storage systems demonstrate significant potential as an innovative power generation configuration. In this study, three cycle systems—helium, molten salt, and water (steam)—were employed to investigate and optimize the performance of the system. A series of modeling and simulation processes were conducted using EBSILON software to explore the impact of various parameters (such as pressure, reheat stages, and temperature) on the thermal efficiency of the power plant under both design and off-design conditions. To further study the system's performance, a thermo-economic analysis method based on the second law of thermodynamics was adopted. A thermal-economic analysis model was established, and a fire use analysis was performed on key equipment under representative conditions. Through this approach, we identified the distribution of fire use losses within the system, with the steam generator being the primary contributor to fire use losses among the three systems. Through comprehensive analysis of the simulation results, we conclude that the system exhibits outstanding thermal-economic performance when high-pressure parameters are combined with high temperature. This insight is crucial for modeling and optimizing the construction of nuclear power plants in China, providing a more comprehensive understanding of factors influencing thermal efficiency and contributing to more informed decision-making for the design and operation of tri-generation nuclear power stations.

Design and Deployment of the Askaryan Radio Array South Pole Autonomous Renewable Power Stations (AARPS)

Research was initiated in 2009 to determine the feasibility of constructing 300W autonomous renewable energy power stations at the South Pole. In January 2011, a test power station was constructed at the South Pole using three small scale wind turbines that included a system health monitor, meteorology and power instruments and remote communications pipeline. Significant testing and development was performed to prepare the hardware and electronics for the sub -40C environment. During December 2011, additional wind turbines and equipment were deployed at the South Pole to upgrade existing systems and perform additional testing. Results of field testing are presented.

Multi-input portable power station design using lithium-ion battery

A portable power station is a power station that can be easily transported to meet the electricity needs of outbound activities, night-time fishing, merchants at night markets, and refugee tents. When natural disasters such as earthquakes, landslides, tsunamis, and floods occur, the electricity network and communication networks are disrupted, despite the urgent need for electricity to supply basic things at the disaster site, such as lighting, charging cellphones, and providing other electronic equipment. This study designed and implemented a portable power station using lithium-ion batteries as a source of electrical energy, with solar modules and the State Electricity Company (PLN) power grid for recharging the batteries. The research method is experimental quantitative, and the power station is intended to generate 300 Wh of electrical energy. Tests performed include: 1) The charging process uses a 1 x 50 Wp solar module and the PLN electricity network; 2). The process of discharging involves a 50-Watt ac-led lamp and a 4.000-mAh smartphone. As a result, the portable power station can function effectively, can provide electrical energy for one 50-watt ac-led lamp for t = 6.27 hours, and can recharge a smartphone six times. While the process of recharging using a solar module took t = 8 hours, it took t = 4 hours when using the State Electricity Company (PLN) power grid.

Time-fractional (2+1)-dimensional navier-stokes equations: similarity reduction and exact solutions for one-parameter lie group of rotations

The current study is dedicated to solving the time-fractional (2+1)-dimensional Navier–Stokes model. The model has wide applications in blood flow, in the design of power stations, weather prediction, ocean currents, water flow in a pipe, air flow around the aircraft wings, the analysis of pollution, and many other areas of engineering. The Lie symmetry approach is applied to the governed time-fractional equation to fulfill this need. In the direction of exact solutions of the time-fractional equation first of all invariance condition is obtained in the presence of the Lie group. Consequently, infinitesimals are obtained with the help of the invariant condition. Moreover, these infinitesimals are utilized to obtain the subalgebras. Further, under each subalgebras similarity variables and similarity solutions are obtained which are used to find the reduced equations. These reduced equations are solved for exact solutions. The solutions of the reduced equations are further used to find the exact solutions of the main time-fractional (2+1)-dimensional Navier–Stokes equation with the help of similarity solutions under each subalgebra.

Thermal runaway propagation behavior and energy flow distribution analysis of 280 Ah LiFePO4 battery

Thermal runaway propagation (TRP) of lithium iron phosphate batteries (LFP) has become a key technical problem due to its risk of causing large-scale fire accidents. This work systematically investigates the TRP behavior of 280 Ah LFP batteries with different SOCs through experiments. Three different SOCs including 40 %, 80 %, and 100 % are chosen. In addition to key TRP characteristic parameters such as temperature, TRP time and speed are analyzed, more importantly, the energy flow distribution during the TRP of large-size LFP module is also revealed. The results indicate that among the three groups of modules, TRP occurs only in the module with 100 % SOC, which is attributed to the higher internal energy (666.11 kJ) and heat transfer power (264.07 W). For the module with 100 % SOC, the TRP time interval fluctuates from 667 s to 1305 s, and the TRP speed is in the range of 0.05–0.12 mm/s. Furthermore, the energy flow distribution indicates that more than 75 % of the energy is used to heat battery itself, and approximately 20 % is carried out by ejecta. Less than 10 % can trigger neighboring batteries into thermal runaway. This work may provide important guidance for the process safety design of energy storage power stations.

An Optimal Design of a Small Photovoltaic Plant with Cost Minimization based on a Real Database of PV Panels and Inverters

The penetration of renewable energy sources and the development of autonomous power systems for the supply of isolated consumers find applications such as covering energy needs in lighthouses, small islands, monasteries, and even isolated special industrial facilities. Power plant cost is a major limitation in the development of these systems. For example, although the electromechanical cost of photovoltaic plants has been significantly reduced in recent years, however the land cost is not considered, which is a significant expenditure. In this paper, the real problem of an autonomous power station design for the supply of the shoreline electrode substation on the Stachtorroi islet of Attica, is taken as the starting point. The electrode substation is part of the Attica-Crete high voltage direct current (HVDC) electrical interconnection project. For the above problem, an overall evaluation algorithm for a photovoltaic (PV) plant is proposed that considers the technical characteristics of the plant, the installation and operating costs (including land costs in addition to electromechanical costs and efficiency of each of the plants components), as well as the actual commercial data of the individual key elements (PV panels, inverters) of various companies, choosing the optimal system through exhaustive search depending on the required power and the deflated capital reduction interest rate

Программный комплекс РАДУГА-Т для моделирования полей нейтронов в ядерно-энергетических установках

Design and operation of nuclear power stations (NPS) are followed by simulation of neutron propagation in these stations. It is necessary to consider borders of multi-scale structural elements consisting of different materials. It is desirable to use parallel computer because of big size of NPSs. To keep such conditions, algorithms and codes for solving the integro-differential transport equation on unstructured grids are being developed. In the paper such algorithms included into the code RADUGA T are outlined. Grids, grid schemes, iterative methods to solve grid equations are presented. Calculation parallelization methods for hybrid computers are considered, MPI and OpenMP techniques are used. Methods of building, improvement, decomposition and visuzlisation of spatial grids are considered. Software implementation is described. The algorithms of the code RADUGA T are compared with methods of other codes. Computation parallelization efficiency study results are presented. The problem of neutron multiplication factor calculation in a light-water reactor model is solved. The multi-processor computer MVS-10P of the Joint SuperComputernal Center is used. Acceleration of each algorithm being used and summary acceleration are given.

Energy management strategy for solid‐state transformer‐based solar charging station for electric vehicles in smart grids

This study introduces a type of solid-state transformer (SST) for solar power station design and an energy management strategy (EMS) for the SST. The purpose of this study is to design a real efficient EMS for the photovoltaic-assisted charging station in smart grid ancillary services and apply the optimal decision method. Also, the energy bound calculation (EBC) model is proposed to find the upper and lower bounds of flexible sources. Also, taking into account the EBC results and the power order from the aggregator, a charge power allocation algorithm is designed to distribute the power of flexible electric vehicles (EVs). With the help of a case study and laboratory analysis, the proposed EMS strategy is effective in real-time energy management and is suitable for practical applications. The obtained results show the stable performance in the calculation of the energy range and real-time power allocation which improves the efficiency of the photovoltaic-based charging station. Also, the SST improves the operation of charge stations for supplying the sustaining power.

High-Accuracy Parameters Identification of Non-Linear Electrical Model for High-Energy Lithium-Ion Capacitor

With the development of extreme fast charging technology, charging stations need to use energy storage stations to reduce the rising peak to average power ratio (PAPR). Lithium-ion capacitor (LIC) is a chemical power source that uses both Faraday process and non-Faraday process to store energy. Because of its attractive performance in terms of rate characteristics and chemical stability, it is suitable for some energy storage stations that consider both power density and energy density. It is important to describe the current-voltage characteristics of LIC to predict the charge and discharge efficiency in the early design of energy storage power stations. During the test, however, a full discharge or charge results in a high temperature rise, and the electrical model parameters near a specific temperature point cannot be accurately obtained. The short current pulses cannot stabilize the polarization. In this paper, a high-accuracy parameters identification method based on an improved Butler-Volmer-Equation-Based electrical model is used to summarize the phenomena caused by the rate of change of high-energy LIC. The accuracy of the method is tested under the dynamic stress condition test. The maximum voltage error is less than 2%. Energy efficiency calculation based on the used model is simulated by the design condition from the energy storage station of the Haizhu line in Guangzhou. The maximum error is less than 0.2%.

Thermal Power Plant Equipment Using IBM SPSS Statistics Mehtod

Thermal Power Plant Equipment. Introduction: A thermal power station is a power station called, the prime mover this is the steam mover. Made to enter the water system then heated, then vaporized will change. The steam rotates in it tries an electric generator and a steam turbine. A type of power plant where thermal energy is transformed into electrical energy is a thermal power plant. Steam high pressure occurs during the formation cycle. A sizable one for creating water steam in a pressure ves-sel. Boiling is accomplished by the application of heat and an electrical generator. The turbine is powered by steam. From the turbine, low pressure the exhaust is in a steam condenser enters, where it heats up the condenser cooled to form, it is more heat to form pressurized steam the process is recycled. This is it is called the Rankine cycle. The design of thermal power stations depends on the intended power source fossil fuel, nuclear and geothermal energy, solar energy, biofuels, and waste incinera-tion is all used. Research significance: Thermal power plant equipment is a power plant that transforms heat energy into electri-cal energy. As part of the steam-generating cycle, high pressure is used to produce steam. An enormous pressure vessel heat to boiling water used, it is an e steam connected to a generator drives the turbine. Traditional thermal power plants: combustion power plants also called, coal, natural gas, heating oil, and biomass-fueled steam boilers with the energy produced by running a steam turbine activates, which is electricity operates a transformer to produce thermal power plants are the most important part of the energy sector one of the important elements, and they of life after water and food as one of the basic needs produces considered electrical energy are masterpieces. Nearly all coal power plants, petroleum power plants, nuclear power plants, geo-thermal power plants, solar thermal power plants, waste incineration plants, and all-natural gas power plants are also hot. Cre-ates what is regarded as electrical energy in gas turbines and boilers natural gas is often burned. Methodology: SPSS statistics is a data management, advanced analytics, multivariate analytics, business intelligence, and criminal investigation developed by IBM for a statistical software package. A long time, spa inc. Was created by, IBM purchased it in 2009. The brand name for the most recent versions is IBM SPSS statistics. Evaluation parameters: water treatment plant, Forced draft fans, Boiler feed pumps, Fuel handling plant, Steam boiler system, Generators, Dust collector system, Mobrey switch, Miscellaneous Auxiliary Equipment. Results: The Cronbach's Alpha Reliability result. The overall Cronbach's Alpha value for the model is .599 which indicates 59% reliability. From the literature review, the above 60% Cronbach's Alpha value model can be considered for anal-ysis.

Electron beam welding of oxide dispersion strengthened 9 Cr martensitic steel-an experimental and theoretical perspective

Abstract Advanced nuclear energy systems present significant improvements in economics, safety, reliability and sustainability over currently operating reactor technologies. Proper choices of cladding and structural material with a. high neutron damage resistance b. good mechanical properties at high operating temperatures and c. low activation properties are essential for the safe and reliable operation of the system. The 9-12% Cr transformable steels with lower carbon (∼0.1%) contents and addition of Mo, W, V, Nb present better high temperature strength than austenitic steels. The use of 9%Cr steel is considered as an optimum solution taking into consideration the present day requirements like environment, efficiency, elasticity, experience and economy that dominate considerations of modern power station design, layout, fabrication and operation. The pursuit of improved efficiency/power plant performance resulted in the design of system operating at higher temperature and pressure, which requires materials with appropriate high-temperature mechanical properties and metallurgical stability at operating temperatures. Oxide Dispersion Strengthened (ODS) 9% Cr steels have the potential to advance the high temperature performance of associated components in advanced nuclear energy systems with marginal oxidation resistance. The research focuses on Electron beam welding (EBW) of Hot Isostatically Pressed (HIP) ODS 9 Cr martensitic steel in as-received condition to arrive at the optimized weld process parameters. The weldments were characterized using Optical Microscopy for depth of penetration and width of weldments. The experimental results were theoretically verified using Minitab software

Simulation Program of Cloud Cover above Solar Power Station

In this article is represented the results of modeling the work of a solar power station under mixed sky conditions (cloud passes over its plane) in software written in Python programming language. As the issue of cost-effectiveness is a decisive one, it is necessary to provide specialists in the design and maintenance of solar power stations as accurately as possible with regard to the predicted station power. In this paper, we presented the way to take into account spatial arrangement and cloud cover in the calculation of solar power station parameters. The algorithm, based on the method that Fournier proposed, is modified to generate fractal cloud for simulating surface horizontal irradiation variability. Steps of the algorithm are presented. The modified algorithm allows us to get a “surface” of the fractal nature, which is a simulation model of the cloud. The algorithm is used to overcome the problem of obtaining sufficiently detailed for the needs of modeling cloud images of low-resolution source data. The model of a cloud is based on the assumption that the clouds are of “fractal nature”. For the chosen formula for calculating the expected intensity of solar radiation, the formula for the transition from cloudiness indices to atmospheric transparency indices is given. The normal projection of the cloud as a two-dimensional array of data represented by atmospheric transparency indices is shown. The program window for simulating the work of the solar power plant and the description of the blocks, from which it is composed, is presented. The main blocks of the program, such as Load Parameters Block, Panel Parameters Block, PV Station Structure Block, Cloud Cover Block, and Cloud Passage Block, are described. For each of the parameters of the model reference information describing the parameter is displayed. To launch the program after data entry, the transition to the modeling menu (Modeling), followed by pressing Run (Ctrl + F9) is made. If there are no errors in the entered data, a simulation window opens. If there was an error when entering the data, then the corresponding message will appear in the program`s status bar. A formula for calculating the power output of a solar power station under the condition that a cloud passes over its surface and a graph of the power curve for specific model parameters are presented. It is shown that the developed program allows obtaining data on the power output of a solar power station in dynamics, which can later be used in the design and maintenance of solar power plants.

Influence of Boiler Thermal Storage Coefficient on Stable Operation of Shipboard Power Station

Stable operation of shipboard turbine generator is a key factor affecting the safety of power grid, and heat storage system influences the stability of turbine main pressure significantly. On the basis of boiler-turbine integral model, prohibition effect of thermal storage system on cyclical disturbance is studied. In order to compare the influences of varied heat storage coefficient on turbine unit stable operation after sudden load, PSCAD simulation software is applied. Result of experimental test based on megawatt turbo-generator has confirmed the conclusion, and this paper may provide reference for further research on shipboard power station design and control.

Geothermal steam condition performance monitoring

Turbine scaling from poor purity steam is a major problem in geothermal power stations. The “true” purity and quality of steam going into geothermal turbines can’t easily be measured in stations equipped with direct-contact condensers. Field testing has also shown that wet steam line samples are generally not representative of steam purity. Measuring sodium flux or chemical tracer injected upstream of the separators in drainpot condensate discharges can be used to determine the steam condition. However, the best measurement method seems to be the measuring of sodium flux.Tracers injected upstream of separators can take a long time to stabilise. The results of tracer studies need to be treated with caution and if they are used for a short interval test, they can give misleadingly optimistic results.Even with reliable representative data, there are very few changes that can be made to improve steam purity or quality without either major capital expenditure or significant load loss. This means that the design of a steam delivery system capable of providing clean dry steam is of vital importance in power station design. Results from existing stations’ performance shows that the design of steam delivery systems is currently being poorly done.

Hydrodynamic Performance Analysis of the Vertical Axis Twin-Rotor Tidal Current Turbine

The goal of this manuscript is to investigate the influence of relative distance between the twin rotors on the hydrodynamic performance of the vertical axis twin-rotor tidal current turbine. Computational fluid dynamics (CFD) simulations based on commercial software ANSYS-CFX have been performed to enhance the understanding of interactions between the twin-rotors. The interactions between the twin rotors are known to have increased the power output efficiency as a whole, and it is, therefore, of great significance to undertake deeper research. The simulation results are found to be consistent with similar research results in the literature in some aspects. The simulation results of stand-alone turbine and twin rotors are compared from three different aspects, including blade forces, power output efficiency and wake flow field. The results showed that the cyclic variations tendency of blade force coefficients of twin rotors is close to that of the stand-alone turbine. The average power output efficiency of the twin-rotors system is higher than that of the stand-alone turbine. The interactions between the turbines increase the power output of the twin turbine system as whole in a wide relative distance range. However, smaller relative distance between the twin rotors does not mean a bigger power output efficiency of such a system. The power out efficiency of such a system would decrease when the relative distance between the twin rotors exceeds the critical point. The power output of the twin rotors reaches the peak value when the ratio between the two main axis distance and diameter of the turbine is around 9/4. This research can provide a reference for the design and development of larger tidal power stations.

МАТЕМАТИЧЕСКАЯ МОДЕЛЬ БАЗОВЫХ КОНЕЧНЫХ ЭЛЕМЕНТОВ В КОНЕЧНО-ЭЛЕМЕНТНОЙ ТЕОРИИ ПОРТОВЫХ ПОДЪЕМНЫХ СООРУЖЕНИЙ

The problem of computational analysis of the seismic safety of lifting cranes specified by the regulatory systems (FPP "Safety Rules for dangerous production facilities using Lifting mechanisms" for standard industrial application cranes; Regulation 31.1.02-2004 "Technical operation rules for carrying and lifting equipment in the sea merchant harbors" for harbor cranes; Code of Design-031-01 "Codes of Design of antiseismic atomic power stations" and Code of Design-043-11 "Rules of Design and safe operating hoisting cranes for objects of use of atomic energy" for cranes used at the nuclear facilities) is currently under discussion, despite the emphasis on the part of scientific community. All this has led to carrying out the research which presented a vision of the problems of designing cranes in earthquake-proof design as a finite element theory of structures, and on the basis of methods of the theory of seismic stability of structures - the linear spectral method, according to the Code 14.13330.2014 "Building in earthquake areas" and the method of dynamic analysis, according to Guidelines 1.5.2.05.999.0025-2011 "Calculation and design of earthquake resistant nuclear power plants". The article highlights the trend of recent years of the increasing complexity of calculated finite element models of structures, often combining both finite element models of buildings and supporting structures, and cranes. A computational analysis of such constructions leads to a combination in the design model of finite elements of different dimensions. The article points out that both the choice of the type of finite elements and the way they are connected together within the framework of one calculation model directly affect the reliability of the results obtained. Based on the practical experience of computational analysis of complex spatial engineering structures, the article proposes stiffness and mass matrices for one-, two- and three-dimensional basic finite elements for calculating port lifting structures.