Turbine Unit Research Articles

Optimization of Weight and Size Characteristics and Unification of Heaters of the Regeneration System of NPP Turbine Units

Optimization of Weight and Size Characteristics and Unification of Heaters of the Regeneration System of NPP Turbine Units

Analisis Viskositas Lube Oil Di Turbin Unit 2 PLTP Lahendong

Viscosity, also known as fluid viscosity, is a fluid characteristic that provides shear stress resistance by the fluid. Viscosity describes a fluid's resistance to a flow so that it can be used to measure fluid friction. The viscosity of a lubricant is affected by changes in temperature and pressure. The pressure increases if the value of the viscosity increases, the higher the pressure, the more significant the fluid's viscosity. This study aims to find out the viscosity value of lube oil in turbine unit 2 of the Lahendong PLTP. Based on the results of the calculation, the result was obtained from the viscosity value of lube oil in turbine unit 2 of 373.61 kg/ms with a pressure of 30591.486 kg/m2, and the viscosity value increased by 386.06 kg/ms due to an increase in pressure of 31611.2 kg/m2.

Матричное моделирование и диагностика состояния регенеративных подогревателей высокого давления

Increasing the efficiency of heat exchangers is a promising area of energy saving, which is one of the priority areas of the development of science, engineering, and technology in the Russian Federation. Improvement of heat and mass transfer in regenerative heaters and condensers of turbine units of thermal power plants can significantly increase the operating efficiency of power equipment. Diagnostics of the condition and improvement of operating modes of the high-pressure regenerative heater which are an integral part of regenerative heating systems for feedwater of turbine units, are urgent scientific and practical tasks. To develop a model of a high-pressure regenerative heater, the methodology of matrix formalization of the description of heat and mass transfer processes has been used. To solve problems of diagnosing the state of heating surfaces of heat exchange equipment, mathematical programming methods have been applied. Within the framework of the matrix formalization methodology, an approach to modeling and solving diagnostic problems of multi-stage heat exchangers considering the phase transition in coolants has been developed. The sensitivity of the resulting model to input signals has been studied. Solutions of the problem of diagnosing the state of a high-pressure regenerative heater have been obtained and analyzed. Analysis of the obtained calculated results has shown an adequate description using the model of the real heat exchange process for the analyzed heater and the possibility to use the proposed model for monitoring and operational diagnostics of power equipment. The proposed approach allows us to formulate and solve inverse problems of diagnosing the state of equipment of heat exchange installations for various purposes.

The primary frequency modulation control strategy based on fuzzy active disturbance rejection control for gas turbines

Gas turbines play a core role in clean energy supply and construction of comprehensive energy system, and the control performance of primary frequency modulation (PFM) of gas turbine has a great impact on the frequency control of the power grid. However, there are some control difficulties in the PFM control of gas turbines, such as the coupling effect of fuel control loop and speed control loop, slow tracking speed and large variation of operating conditions. To relieve the above difficulties, a control strategy based on the fuzzy-modified active disturbance rejection control (F-MADRC) proposed in this paper. Based on the analyses of the parameter stability region for active disturbance rejection control (ADRC), fuzzy tuning rules of parameters for F-MADRC are designed. Finally, the proposed F-MADRC is applied to the PFM system of MS6001B heavy-duty gas turbine. The simulation results show that the gas turbine unit with the proposed method can obtain the best control performance of the PFM with strong ability to deal with system uncertainties. The proposed method shows good engineering application potential.

Performance Prediction of A Power Generation Gas Turbine Using An Optimized Artificial Neural Network Model

This paper presents the application of an Artificial Neural Network (ANN) based model for performance ‎prediction of a power generation gas turbine. The suggested model was optimized to provide a large ‎database for comparison between different ANN topologies. Then, based on the optimization results, the ‎Multi-Layer Perceptron (MLP) of two layers was constructed and utilized for this study as the best-‎optimized topology. Training of this model was done using historical operational data of a Rolls Royce ‎‎(RB21-24G) gas turbine unit. The outcome results from this model used for performance prediction show ‎good accuracy for different ambient conditions and variable power ratings. Then, a degradation study was ‎also introduced comparing measurements of the same gas turbine utilizing one year later, on-site ‎operational data, with the predicted values generated by the ANN model. The result shows consistency ‎between the measured data and the model results.‎

The throughput capacity of the main gas pipeline when transporting gas-hydrogen mixtures

To determine the effect of hydrogen concentration in the gas-hydrogen mixture on the throughput capacity of the main gas pipeline and the volume of energy transported by it. The range of molar concentrations of hydrogen in the gas-hydrogen mixture up to and including 20%, which does not require significant technical modernisation of the system, was investigated.Performing theoretical studies and applying mathematical modelling methods to establish the regularities of thermo hydrodynamic processes in a gas pipeline, gas turbine and centrifugal blowers while transporting gas-hydrogen mixtures.In the example of a gas turbine unit widely used in the gas transmission system of Ukraine, it was found out that the molar content of hydrogen, if it does not exceed 20%, has a negligible effect on its rated power and other energy parameters. Adding hydrogen to natural gas with the above molar content will lead to a slight decrease in the pipeline system's capacity (up to 5%) and a significant reduction in the volume of energy transportation (up to 18%).The next stage of the study is to determine the impact of gas-hydrogen mixture properties on the pipeline capacity, taking into account changes in seasonal factors and the degree of system load.A method and software have been developed to predict the pipeline capacity and energy transfer volume for the transportation of gas-hydrogen mixtures, taking into account the influence of seasonal factors, gas-dynamic characteristics of blowers, and combinations of gas-pumping units at compressor stations.Modern international standards are used to calculate gas-hydrogen mixtures' physicochemical and thermodynamic properties under standard and operating conditions. The originality of the approach lies in the fact that the compressor station and the linear section of the gas pipeline are considered as a SLE gas-dynamic system.

Rational Mode Parameters of Power Units Operating in Modern Energy Market Conditions

The paper analyzes the operation of condensing and heating turbines in modern energy market conditions with an assessment of the impact of operating parameters of live and secondary steam on economic indicators. It has been shown that when operating at variable loads, the most effective in terms of high-pressure turbines is a rational reduction in the initial pressure ps (sliding pressure), which leads to an increase in thermal efficiency by 1-1.5%. The experimental results of a study of the vacuum effect in the condenser on fuel consumption are presented in the paper as well. Using a specific example of the K-320-26.5 turbine unit, the need for a rational choice of cooling water flow in winter season to ensure optimal vacuum is shown. The issue of choosing a rational steam reheat temperature tr is examined in more detail. It has been established that one of the main reasons for the decrease in the efficiency of turbine units when operating in variable modes is the irrational use of the reheat temperature and the heat of phase transition in the flow part of the low pressure cylinder. The physical explanation of these processes in the turbine as tr decreases is given in detail. It has been shown that, as a result of analyzing the operation of turbine units of various capacities, a rational choice of reheat temperature (reducing tr by 10-20 °C) increases thermal efficiency by 1-2 %, and turbine efficiency - by 0.4-1.0 %. It is recommended to consider the pressure of the hot steam of the high pressure cylinder (рs), the pressure in the condenser (рc=f(tcirc.water)), as well as the reheating temperature tr, which altogether leads to a reduction in heat consumption by 2.5-3.5 % as rational parameters of steam when operating in variable modes. In order to increase the economic efficiency of the operation of turbine units of TPPs and CPPs at reduced loads, it is recommended to revise the regulatory documentation on the current amendments for changes in the reheat temperature. It is stated that with strict adherence to the recommendations discussed above, fuel savings at TTPs and CHPs in Ukraine can amount to 250–300 thousand tons of coal per year.

Исследование новой микрофакельной горелки с помощью программы Ansys Fluent

A study of a new micro-flame burner device (MFBD) for the combustion chamber of a gas turbine unit (GTU) using the Ansys Fluent program is presented. Research objective: determination of the optimal operating modes of the investigated burner, initial air parameters for maximum combustion efficiency, examination of the uniformity of the temperature field, and the concentration of nitrogen oxides in the combustion chamber of the gas turbine unit with the MFBD. The features of the design and operation of the micro-flame burner device are described, as well as the stages of modeling combustion processes in the Ansys Fluent software. The calculations conducted using various simulation parameters in this program allowed the evaluation of the efficiency of the new MFBD, determination of the temperature field distribution, and the nitrogen oxide content in the combustion products. The nitrogen oxide emissions in the combustion products during different modes of operation did not exceed 9 ppm. This data will be useful for further optimization and development of GTUs taking into account the requirements of efficiency and environmental safety. The presented study demonstrates the application of Ansys Fluent in the development of new technologies in the field of combustion and energy

Thermal analysis of an integrated solar combined cycle power plant and its application in southern Iraq

Recently, simple cycle play a significant role in electric power production in Iraq. However, those units suffer from low thermal efficiency and low power output. In the present work, theoretical study is carried out aiming to improve the performance of (AL-Amara station 125MW). The present work includes three parts: the first part focus on the effect of ambient temperature on the performance of simple cycle including mass flow rate, power output, thermal efficiency and other parameters. In the second parts, a modification to simple cycle is implanted to be a combined cycle. The third part is studied the benefit of using solar unit for producing more steam to be supplied to the heat recovery steam generator wishing to produce more power and low emissing. Regarding, to simple gas turbine unit, the obtained results show that the mass flow rate is decreased nearly (10.8%) when the ambient temperature increased from (15-50) ºC. However, this reduction in mass flow rate of air is led to significant reduction in power output and thermal efficiency nearly (22.6%,13.2%) respectively. In the second parts, applying combine mode show a significant increase in power output and thermal efficiency nearly (32.5% and 32.3%) respectively. while the specific fuel consumption is decrease nearly (32.19%). Finally, the third parts when solar units are used, the gathered results show an acceptable increase for the amount of steam produced via solar units (21.02kg/s). The overall performance of the integrated cycle shows that the power output and the thermal efficiency increased nearly (11.28%and10%).

Ultra-Short-Term Power Prediction of Large Offshore Wind Farms Based on Spatiotemporal Adaptation of Wind Turbines

Accurately predicting the active power output of offshore wind power is of great significance for reducing the uncertainty in new power systems. By utilizing the spatiotemporal correlation characteristics among wind turbine unit outputs, this paper embeds the Diffusion Convolutional Neural Network (DCNN) into the Gated Recurrent Unit (GRU) for the feature extraction of spatiotemporal correlations in wind turbine unit outputs. It also combines graph structure learning to propose a sequence-to-sequence model for ultra-short-term power prediction in large offshore wind farms. Firstly, the electrical connection graph within the wind farm is used to preliminarily determine the reference adjacency matrix for the wind turbine units within the farm, injecting prior knowledge of the adjacency matrix into the model. Secondly, a convolutional neural network is utilized to convolve the historical curves of units within the farm along the time dimension, outputting a unit connection probability vector. The Gumbel–softmax reparameterization method is then used to make the probability vector differentiable, thereby generating an optimal adjacency matrix for the prediction task based on the probability vector. At the same time, the difference between the two adjacency matrices is added as a regularization term to the loss function to reduce model overfitting. The simulation of actual cases shows that the proposed model has good predictive performance in ultra-short-term power prediction for large offshore wind farms.

Studies on the Experimental Measurement of the Low-Frequency Aerodynamic Noise of Large Wind Turbines

With the continuous warming of the global climate, expanding the use of renewable energy has become one of the main social responsibilities. However, as the number of installed wind turbines and their physical dimensions continue to increase, the issue of generated noise has become increasingly significant in influencing the acceptance and endorsement of wind power projects by neighboring communities. In this paper, we investigated the noise generated by two wind turbine units with rated powers of 1.5 MW and 4.5 MW and analyzed the variations in low-frequency noise during their operation and shutdown periods. This research shows that the power of a single unit has a significant impact on the low-frequency noise emitted into the environment. Compared with 1.5 MW wind turbines, 4.5 MW wind turbines generate more low-frequency noise when operating at the same wind speed. Further analysis of the narrowband frequency spectra and one-third octave spectra of the measured noise indicates that the low-frequency noise from the 4.5 MW wind turbine increases significantly in the range of approximately 80 Hz to 300 Hz, with more pronounced variations below 250 Hz corresponding to changes in wind speed. However, the overall variations in low-frequency noise with wind speed are not as notable as those observed for the 1.5 MW wind turbine. Due to the relatively weak attenuation of low-frequency noise in the atmosphere, the higher low-frequency content of large wind turbines may cause more distress to residents near wind farms. The result of this study emphasizes that in the planning and design of wind power projects, in addition to considering the efficiency of single-unit power generation and the contribution of renewable energy, it is also necessary to pay full attention to noise emission issues to ensure that the project is widely supported and accepted in the community.

ANALYSIS OF THE APPLICATION OF RENEWABLE ENERGY AT THE MUARA ANGKE PASSENGER PORT AS A MEANS OF SUPPORTING THOUSAND ISLAND TOURISM

Kepulauan seribu are also a frequently visited destination for domestic and foreign tourists and are among the priority destinations in Indonesia. The development of the passenger port in Muara Angke is an important step in supporting the tourism sector in Kepulauan Seribu. However, this development must also consider environmental impacts, including carbon emissions and the use of natural resources. Indonesia has taken steps towards developing renewable energy and policies that support it by implementing renewable energy at the Muara Angke Passenger Port will be in line with government initiatives to achieve energy targets national renewable. The method used is primary data, secondary data, by calculating the need for solar panels and wind turbines and collecting supporting data sourced from related websites. The results are 324 solar panels placed on the roof of the main building of the port where the wind turbine is placed on the west side. with a total of 6 units, on the east side of the port there are 6 units and on the south side of the port there are 4 wind turbine units

Data-model-interactive enhancement-based Francis turbine unit health condition assessment using graph driven health benchmark model

As the data-driven Francis turbine units (FTUs) deterioration assessment method is widely investigated, the data quality in actual industrial scene has become an important prerequisite to restrict the method performance. However, existing data augmentation methods often lie in simply mixing real data and simulated data, ignoring the inherent cross-domain state relationships. In this paper, a data-model-interactive enhancement-based FTU health condition assessment using graph driven health benchmark model (HBM) is proposed. First, the pseudo-signals outputs of the mechanism digital twin (DT) model by calculative fluid dynamics (CFD) calculation are modified by critical working condition parameters, extending the theoretical assessment domain. To achieve data-model-interaction through cross-domain state coordination of digital and real data, a digital-reality hybrid graph is constructed from nodes mixing both actual and pseudo through node similarity. The hybrid spatial condition structure created by capture node status association explicitly enhances the sample representation ability. Avoiding excess noise effects, a knowledge-based unsupervised graph pruning regulation is adopted to refine the original graph considering noise and data reality. Finally, the spatial–temporal dependencies hidden in the refined graphs are mined by the designed hybrid graph neural network-based HBM, and output the assessed degradation label values. Verification experiments show that the proposed assessment method can effectively fit FTU deterioration under low-quality onsite data, and is more robust than the comparison methods.

Life cycle environmental analysis of offshore wind power: A case study of the large-scale offshore wind farm in China

China's decarbonization is indispensable for the large-scale utilization of renewable energy. In this process, the development of offshore wind energy has become an important support, because in the eastern region of China, especially the coastal areas, there's the most load requirements but limited onshore renewable resources. Under the goals of both carbon neutral and sustainable development, however, there's still a research gap in evaluating the environmental impacts of large-scale offshore wind plants in China. In this study, the research performed a comprehensive process-based life cycle environmental analysis of a large-scale (400 MW) offshore wind farm with large wind turbine units (5 MW) in China. Global Warming Potential is 25.73 g CO2-eq/kWh and greenhouse gas payback time is calculated as 12.05 months. Fossil fuel consumption amounts to 0.31 MJ/kWh with an energy payback period of 25.56 months. Material resources and ecotoxicity to freshwater need more attention with the values of 1.68 CTUe/kWh and 3.32 10−6 kg Sb-eq/kWh, respectively. The manufacturing stage contributes most to all the impacts examined. The disposal and recycling process shows significant environmental benefits for most impacts but exerts burdens on the particulate matter. Focusing on Global Warming Potential, the wind turbine generation set has the highest effect, among which the blades contribute 73.2% of it. Further, the evolution of electricity and heating mix of China and use of biomass-based precursors could decrease 57% of the blades' greenhouse gas emissions in 2050. This study could provide guidance on the sustainable design and policy-making of offshore wind farms.

Hydrodynamic Analysis Of Water Hammer Phenomena In Hydropower Stations Under Turbine Extreme Operating Conditions

This research article investigates transient hydraulic effects, particularly water hammer phenomena, in a hydropower plant (HEPP) through a comprehensive mathematical model and simulation analysis. Utilizing methods of characteristics and FORTRAN programming, the study develops a model that incorporates water hammer considerations, including friction, in the water conveyance system of the HEPP. The system layout encompasses an upstream reservoir, penstock, turbine unit, and downstream reservoir. The research explores the influence of guide vane closure and pressure regulating valve (PRV) opening and closing laws on pressure variations, mass oscillations, and water level fluctuations within the system. Numerical results indicate that PRV failure may not significantly impact turbine speed, but it results in excessive pressure oscillations in the spiral casing head, exceeding allowable pressure control values. The study identifies a critical PRV diameter of 0.6m, causing a maximum pressure in the spiral case of 370m, surpassing the acceptable limit of 250m, with a speed rise rate exceeding 50%. Conversely, a PRV diameter greater than or equal to 0.9m leads to unnecessary water energy loss. The findings emphasize the importance of carefully selecting PRV parameters to optimize system stability and efficiency. The study's comprehensive analysis provides valuable insights into the interplay of various parameters, contributing to a scientific basis for optimizing operational parameters and ensuring reliable and efficient hydropower plant performance.
 

Vibration control on coupled unit-plant structure of pumped storage power station during sudden load-up process

The versatile regulatory capacity of pumped storage power station (PSPS) stems from the reversible pumped turbine unit switching between multiple operating conditions. Nevertheless, the unit and plant structure experience heightened vibrations owing to the intricate interplay of hydraulic, electrical, and mechanical excitations during transition processes, and the vibration responses fluctuate as operating conditions shift, posing a significant challenge to the safety and high quality operation of power station. To tackle the practical engineering issue, this paper delves into the sudden load-up scenario in power generation situation of pumped turbine, leveraging a finite element model encompassing the coupled hydraulic-mechanical-electrical-structural system (HMES) of PSPS and a mathematical model of unit shaft system, the impacts of dynamic loads induced by various vibration source on the unit and plant structure during transient condition, are meticulously analyzed and discussed through numerical simulations. Additionally, the magnetorheological damper (MRD), is incorporated into the PSPS to explore the effectiveness of MRD in controlling transient vibration in the interconnected unit-plant structure. The results indicate that the system parameters and associated load excitations undergo rapid fluctuations during the load-up process, bringing about noticeable oscillations in vibration amplitudes of rotor and turbine. The floors and fan hood of plant are the most vulnerable areas in terms of structural strength, with associated displacement amplitudes being most noticeable. The incorporation of MRD proves to be highly effective in mitigating the unsteady vibrations in both the unit and the plant structure during load-up course, as well as optimizing the motion patterns of rotor and turbine, promoting a notable reduction in frequency amplitudes of spectrum. Moreover, the maximal transient displacement amplitude of unit is significantly diminished, with the rotor experiencing a decrease of approximately 79%, while the amplitude of turbine declines by 16%. The displacement fluctuation ranges of the plant structure are observably diminished, and the complex frequency components of vibration signal are efficiently controlled. The transient vibration characteristics of the coupled unit-plant structure and the damping behavior of MRD during the transition process are unveiled by the research findings in this paper, which can offer valuable insights for the stability assessment and the research on vibration management of HMES for PSPS under the unsteady operation conditions.

Comparative Technical and Economic Analyses of Hydrogen-Based Steel and Power Sectors

Decarbonizing the current steel and power sectors through the development of the hydrogen direct-reduction iron ore–electric arc furnace route and the 100% hydrogen-fired gas turbine cycle is crucial. The current study focuses on three clusters of research works. The first cluster covers the investigation of the mass and energy balance of the route and the subsequent application of these values in experiments to optimize the reduction yield of iron ore. In the second cluster, the existing gas turbine unit was selected for the complete replacement of natural gas with hydrogen and for finding the most optimal mass and energy balance in the cycle through an Aspen HYSYS model. In addition, the chemical kinetics in the hydrogen combustion process were simulated using Ansys Chemkin Pro to research the emissions. In the last cluster, a comparative economic analysis was conducted to identify the levelized cost of production of the route and the levelized cost of electricity of the cycle. The findings in the economic analysis provided good insight into the details of the capital and operational expenditures of each industrial sector in understanding the impact of each kg of hydrogen consumed in the plants. These findings provide a good basis for future research on reducing the cost of hydrogen-based steel and power sectors. Moreover, the outcomes of this study can also assist ongoing, large-scale hydrogen and ammonia projects in Uzbekistan in terms of designing novel hydrogen-based industries with cost-effective solutions.

Selection of a Heat-Recovery Turbine Unit for a Self-Contained Power Supply of Compressor Stations in Gas Mains

Selection of a Heat-Recovery Turbine Unit for a Self-Contained Power Supply of Compressor Stations in Gas Mains

Optimization Of Gas Turbine Performance 2.1 Using the Overhaul Combustion Inspection Method

Gas turbines are one type of internal combustion drive, the initial mover utilizes gas combustion as a fluid to rotate the turbine with internal combustion. Gas turbines at private companies producing electricity use the initial movers, namely gas turbines and steam turbines. Therefore, it is also called the "Steam Gas Power Plant/PLTGU.”Private company especially in Block 2, uses two gas turbine units with Mitsubishi GT 2.1 specifications which are used as the initial drive of the generator. Types of overhauls in gas turbines are divided into three, including turbine inspection, combustor inspection, and major inspection. In maintaining the reliability of the GT 2.1 Gas Turbine, an overhaul combustion inspection was carried out in the combustion chamber because there was an increase in heat rate of 17,9% which caused a decrease in thermal efficiency and net turbine power of the GT 2.1 Gas Turbine by 17% and 2,1%. So that steps are taken to optimize the GT 2.1 Gas Turbine with the combustion inspection method by repairing and cleaning the combustion bucket nozzle. Increased thermal efficiency by 27,8% or 27,13% to 36,01% from data before overhaul. This was also followed by an increase in compressor power and turbine power so that the net turbine power increased by 38% or 141339,35 hp to 195246,54 hp.

Моделирование работы газотурбинной установки SGT5-4000F с исследованием влияния режимных и климатических факторов на устойчивость горения в камере сгорания

When regulating gas turbine units, it is necessary to be confident in the stable combustion process in the combustion chambers, considering the dynamics of the processes and changes of external climatic factors. Many scientific studies are devoted to the problems of experimental research and mathematical modeling of processes in combustion chambers. The possibilities of flame failure, expansion of the lower limit of combustion, determination of the stable position of the flame front and other issues have been assessed. Even though the problem of design of mathematical models and their use remains relevant. The purpose of this research is to model and study the influence of operation and climatic factors on the stability of combustion in the combustion chamber of the SGT5-4000F gas turbine unit. The subject of the research is the SGT5-4000F gas turbine unit with a low-emission combustion chamber. The simulation model of the gas turbine unit has been developed in the environment of dynamic modeling of technical systems SimInTech. The research is carried out using theoretical methods of calculating fuel combustion, thermodynamic foundations of the theory of gas turbine engines, methods of mathematical and simulation modeling, as well as data from the archive of automated process control systems. A simulation model of SGT5-4000F gas turbine unit has been developed. It is distinguished by the ability to assess the proximity of the compressor operating mode to the stability limit and determine the boundaries of stable combustion procedure in the combustion chamber, considering environmental climatic factors. The authors have studied the stability of the compressor and combustion chamber. The results of the experimental studies of a gas turbine unit in the operating load range from 113 to 282 MW and in the range of outside air temperature from –12 to 30 °C have shown that the combustion process in the combustion chamber is unvarying over the entire operational stress spectrum. The results obtained are verified by comparing model values with technological parameters of a gas turbine unit taken from the archive of the power plant control system. The authors have assessed the influence of electrical load on the performance indicators of a gas turbine unit at outdoor temperatures of +30, +15 and –12 °C. According to the results of simulation modeling, the model of SGT5-4000F gas turbine unit is found to be adequate. The developed model can be used as a tool at the stage of functional and technological design of automated control systems for the development of effective automatic control systems.