Equipment Of Thermal Power Plants Research Articles

Influence of Parameter Deviations Vis-à-Vis Assignment Schedule on Thermally Stressed State of Main Thermal Power Plant Equipment

Influence of Parameter Deviations Vis-à-Vis Assignment Schedule on Thermally Stressed State of Main Thermal Power Plant Equipment

Neural network for predicting operating modes and calculating energy characteristics of steam turbine plants

The article describes the results of work on the creation of neural networks calculating the technical and economic parameters of all possible modes of operation of a thermal turbine unit with a steam turbine of type PT-60-130/13. In accordance with the objectives set, recommendations for the preparation of training data samples are formulated. The input and output parameters of the condensing and heating modes of operation of the steam turbine are determined. The results of research on determining the most optimal architecture of neural networks for calculating the energy characteristics of steam turbine plants of the heating type are presented. The results of calculations of the mean squared errors of neural network predictions from the results of calculations performed using a verified object-oriented model of a PT-60-130/13 turbine unit are tabulated.Graphs of the dependence of the specific heat consumption for the generation of electrical energy on the power of a PT-60-130/13 turbine unit for condensation and heating modes of operation using neural networks are plotted. The conclusion is formulated about the possibility of using neural networks for the development of energy characteristics and regulatory documentation on fuel use of equipment of thermal power plants.

Multiobjective optimization of laser welding parameters for P92 steel based on MFO/MOEAD-Kriging

P92 steel is used in steam equipment of thermal power plants and nuclear power plants. It needs to withstand high temperature and high pressure during service, so high-quality welds are required. Laser welding can easily obtain good weld quality and reduce the probability of coarse grains and welding defects in the heat-affected zone. Post-weld deformation, residual stress, and weld hardness are important indexes for evaluating weld quality, which largely depends on the combination of laser welding process parameters. The multiobjective optimization methods of moth-flame optimization (MFO) and multiobjective evolutionary algorithm based on decomposition under the Kriging model were compared in this research. It was found that the MFO algorithm has a faster optimization speed and better overall effect. The Optimal Latin hypercube sampling method was used to design the simulation test. The welding seam-forming process was simulated by the SYSWELD software. The Kriging model was used to make the nonlinear relationship between the process parameters and the weld quality indexes significant. A new data set was designed to evaluate the accuracy of the model. On this basis, the efficiency of the combination of process parameters optimized by the two algorithms was compared. The simulation and experimental results were in good agreement with the multiobjective optimization results of the MFO. In the experimental verification, the optimized weld quality was analyzed from the aspects of microstructure and mechanical properties. The results showed that the multiobjective optimization method quickly and effectively reduces the probability of weld quality defects in actual welding, thereby improving weld quality. This multiobjective optimization method provides valuable research ideas for engineering research and development to effectively shorten its development cycle.

Boiler Combustion Adjustment and Economic Operation Affect Boiler Combustion Factors

Thermal power generation, as the most stable power output in China, plays a rather crucial role in the construction of China's economy. The most important power generation equipment of thermal power plant is the boiler, only good control of the boiler operation of the power plant, in order to better enable it to participate in the power generation work. Combined with the Linfen Thermal Power Co., Ltd. related boiler unit operation status, combustion adjustment optimisation content analysis, give the corresponding recommendations, so as to make the boiler operation more stable, safe, environmentally friendly, power plant power generation to make the corresponding contribution.

Analysis of Hua Power Plant Beckles Stress Simulation Analysis

The thermal pipeline is important to play an important role in the operation of thermal power plant equipment, and the safe and stable operation of the body and accessories is very important. The elbow, as an indispensable part of the thermal pipeline, directly affects the safety of the unit. On the basis of the GB/T 16507-2013 “Water Pipe Boiler” standard, this article uses the simulation simulation software to analyze the stress of 90 ° elbow under different bending radius. Distribution status. The calculation results show that: under the same wall thickness, the maximum stress is concentrated in the inner arc. As the curved radius R increases, the maximum stress of the inner arc gradually decreases. At the same time Instead, it gradually increased. Under different wall thickness, the maximum stress occurs at the outer arc.

Structural and Economic Approach to the Selection of Peak Regulating Capacities at Thermal Power Plants

The output of power unit No 2 of the Belarusian NPP to the level of neutron power development of 100 % of the nominal level has changed the structure of generation of the Unified Energy System (UES) of Belarus. At the current loads of the inter-heating period of 2023, the share of a nuclear power plant with two power units operating at full capacity in the daily generation structure of the Republic is about 50 %. In order to balance the UES of Belarus during the operation of two power units of a nuclear power plant at night, the application of adjustment regulatory measures that exceed the available capabilities is required. The almost complete use of the adjusting range of the CHP will forcibly cause, on a larger scale, to the shutdown of the blocks during the load failures at night, followed by the start-up from the non-cooled and hot statuses. These operating modes of generating equipment are inevitable in the current conditions of the electricity market, which has led to the emergence of most complex tasks to assess the economic and technical efficiency of involving or another equipment of power plants in such modes. The paper proposes an approach to solving the problem of achieving an effective combination of reliability and efficiency of energy systems on the example of gas turbines and CCGT power units. A generalized desirability function has been obtained, which includes a number of parameters for choosing a rational relationship and mutual influence between the reliability and efficiency of electricity production with the participation of thermal power plant equipment in regulating the daily load schedule. The proposed mathematical model is an effective means of analyzing the suitability of equipment for use in the required operating modes.

Modal Analysis and Optimization of Fluid-Structure Coupling for Rotor and Inner Cylinder of Vertical Condensate Pump

Background: Low-frequency resonance is one of the common issues encountered during the variable-frequency operation of condensate water pumps. There have been numerous patents and papers proposing solutions to address the low-frequency resonance problem in condensate water pumps. However, the solutions for resonance problems often need to be tailored to specific circumstances. background: Condensate pump is one of the important auxiliary equipment of thermal power plant, which consumes a lot of electric energy in the production process. Improving the efficiency of condensate pump can save energy and reduce consumption. Variable frequency operation is an effective method to improve the efficiency. However, the condensate pump is prone to excessive vibration in the process of frequency conversion operation, which affects the safe operation of the condensate pump Methods: Based on the acoustic method, the dynamic model of the rotor and inner cylinder of Jiangsu Guohua Chenjiagang Power Plant 2B condensate pump is established to compare the difference between dry modal and fluid-structure coupling modal, the influence of perpendicularity, concentricity and bearing wear on the natural frequency of rotor is studied. objective: In order to systematically understand the modal characteristics of the condensate pump rotor and inner cylinder under the fluid-structure coupling condition, a three-dimensional finite element model of the 2B condensate pump rotor and inner cylinder in Jiangsu Guohua Chenjiagang Power Plant was established. Results: The rotor is rigid under normal conditions. When the bearing is worn, the frequency of the rotor will be greatly reduced and may fall into the frequency conversion operation range to excite resonance. The deviation of perpendicularity and concentricity will not directly lead to the decrease of rotor modal but will lead to the increase of bearing stress, aggravate bearing wear, and then affect the rotor modal. As the inner cylinder only relies on the fixed support at the top, the structure stiffness is low, which may lead to low-frequency resonance. By adding two support structures at the guide vane, the first-order modal frequency of the inner cylinder can be increased from 3.29 Hz to 28.88 Hz, effectively avoiding the operating frequency range of the system. method: The fluid-structure coupling modal of the rotor was calculated based on acoustic method, and the difference between the dry modal and the fluid structure coupling modal was compared. At the same time, the influence of the rotor perpendicularity, concentricity related installation parameters and bearing wear on the modal was studied. Conclusion: This study can guide the optimization of similar pump structures. result: 1. The fluid-structure coupling modals of both the rotor and the inner cylinder are much lower than the dry modal. Compared with the dry modal, the first two orders of fluid-structure coupling modals of the rotor are reduced by 8.11%, while the first two orders of fluid-structure coupling modals of the inner cylinder are reduced by more than 25%, which is mainly caused by the additional mass of the fluid. Therefore, when conducting modal analysis, it is necessary to consider the effects of fluid forces. The frequency conversion operation range of the condensate pump is 15-25 Hz. In this operation range, there is no resonance point for the rotor, which is rigid under normal working conditions. The 3rd and 4th modals of the inner cylinder are located within the range of variable frequency operation, which may cause resonance during variable frequency operation of the condensate pump. 2. The deviation of perpendicularity and concentricity will not cause the modal frequency decrease of the rotor, on the contrary, it will cause the frequency increase of some modals. The stress on the bearing is very small when the rotor is mounted without deviation. When the perpendicularity and concentricity of the rotor is deviated, the stress on the bearing increases dramatically, thus accelerating the wear on the bearing system. The influence of different bearing wear on the rotor modal varies greatly. Generally speaking, the rotor modal will be reduced. Some have even been reduced to the frequency conversion operation range, so it can be seen that although the perpendicularity and concentricity deviation does not directly affect the modal frequency, it will accelerate the wear of the bearing, and then lead to the reduction of the modal frequency. 3. The first four modals of the inner cylinder are all below 25 Hz. By finite element calculations, it was found that after adding two supports, all modals of the inner cylinder increase above 25 Hz. other: No additional remarks provided.

Development of software for the management of the maintenance of equipment of thermal power plants

The relevance of the use of thermal power plants for the generation of thermal and electric energy on the territory of the Russian Federation is revealed, taking into account its geographical and climatic features. The substantiation of the importance of the process of maintenance and repair in relation to boiler units, which are operated at thermal power plants, is given. Difficulties accompanying the practical implementation of this process are identified. The influence of the identified difficulties on the existing shortcomings in the process of maintenance and repair of boiler equipment and the technological pipelines connecting them and pipelines of steam and hot water is shown. The goal of the study is set, which is aimed at eliminating the identified objective difficulties and the tasks are formulated, the solution of which will contribute to the achievement of the goal. The necessity of developing specialized software for managing the process of maintenance and repair of equipment and pipelines of boiler units of combined heat and power plants is substantiated. The methodology of the work is based on the development of digital models of pipelines and boiler equipment, as well as algorithms aimed at processing the parameters of digital models. The software implementation of the developed models and algorithms is made by means of object-oriented programming in the form of a client-server application for the Windows operating system. The description of the results of software development aimed at solving the set tasks is given. Examples of some dialog boxes accompanying the functioning of the developed software are given, as well as examples of created digital models of boiler equipment and their individual elements. The practical application of the research results contributes to an increase in the degree of digitalization of industrial production in general and energy production in particular. The results obtained in the framework of this work, in the form of software, can be used to accompany the process of maintenance and repair of boiler equipment of combined heat and power plants. With appropriate adaptation, the results obtained can also be applied to boiler equipment, pipelines and apparatus that are used in the chemical, petrochemical and oil refining industries.

Monte-Carlo method for assessing and predicting the reliability of thermal power plant equipment

Monte-Carlo method for assessing and predicting the reliability of thermal power plant equipment

Problems of Adapting the Operating Thermal Power Plant Equipment to the Technological Emission Indicators Stipulated by the Reference Document on Best Available Techniques 38-2022 “Large Combustion Plants”

Problems of Adapting the Operating Thermal Power Plant Equipment to the Technological Emission Indicators Stipulated by the Reference Document on Best Available Techniques 38-2022 “Large Combustion Plants”

Energy-Efficient Solutions in Design, Construction and Operation of Thermal Power Plants and Heating Networks

The article deals with topical issues related to the introduction of energy-efficient measures in the energy sector of Russia. A comprehensive study and research of the current situation in the field of technological processes for generating electric and thermal energy of thermal power plants (hereinafter TPP), transportation and distribution of energy in thermal networks has been carried out. The analysis of the main equipment and the parameters of the working environment influence on the efficiency of the thermal power plant, taking into account the technological features and energy losses of the steam power cycle of heat and electric power generation, was carried out. The main existing problems and sources of energy losses in heat supply systems are considered. Recommendations are given for introduction and development of energy-efficient solutions and technologies in the design, construction and operation of thermal power plants and heating networks. Promising measures aimed at maximum effect of energy saving are proposed for consideration, including the design and construction of new or modernization of existing thermal power plant equipment, the introduction of combined-cycle power plants, the use of frequency drives of critical rotating mechanisms, the introduction of automatic or remote manual process control systems, the introduction of digital production, including digital counterparts of objects, digital heating points and electrical substations, installation of additional sensors and metering devices with the introduction of monitoring systems and predictive prognostics of equipment, the use of geo-information systems with visualization of three-dimensional schemes and the development of mathematical models of heating networks, carrying out a full-scale instrumental control of critical pipelines metal using robotic complexes. Practical examples of energy-efficient measures application at existing thermal power plants and heating networks are given.

Advances in Fault Detection and Diagnosis for Thermal Power Plants: A Review of Intelligent Techniques

Thermal power plants (TPPs) are critical to supplying energy to society, and ensuring their safe and efficient operation is a top priority. To minimize maintenance shutdowns and costs, modern TPPs have adopted advanced fault detection and diagnosis (FDD) techniques. These FDD approaches can be divided into three main categories: model-based, data-driven-based, and statistical-based methods. Despite the practical limitations of model-based methods, a multitude of data-driven and statistical techniques have been developed to monitor key equipment in TPPs. The main contribution of this paper is a systematic review of advanced FDD methods that addresses a literature gap by providing a comprehensive comparison and analysis of these techniques. The review discusses the most relevant FDD strategies, including model-based, data-driven, and statistical-based approaches, and their applications in enhancing the efficiency and reliability of TPPs. Our review highlights the novel and innovative aspects of these techniques and emphasizes their significance in sustainable energy development and the long-term viability of thermal power generation. This review further explores the recent advancements in intelligent FDD techniques for boilers and turbines in TPPs. It also discusses real-world applications, and analyzes the limitations and challenges of current approaches. The paper highlights the need for further research and development in this field, and outlines potential future directions to improve the safety, efficiency, and reliability of intelligent TPPs. Overall, this review provides valuable insights into the current state-of-the-art in FDD techniques for TPPs, and serves as a guide for future research and development.

Design of Robbing Control Logic for Auxiliary Equipment in Thermal Power Plants

In order to reduce the probability of unit non-stop caused by factors such as control loop interference, open contact misoperation and low cable insulation, and to narrow the scope of system misoperation, This paper starts with the analysis of typical faults of control systems in recent years in thermal power plants, combines with the daily emergency response operation habits of operators, optimizes and adjusts the control strategy, and designs the “robbing control logic” module, which replaces the emergency operation of the operators and solves the misoperation caused by the control system abnormality, and realizes that it will not lead to the occurrence of accidents or the expansion of the range of accidents under the conditions of misoperation, so as to enhance the attribute of the control system’s intrinsic safety, and to provide references for the development of the control system’s intrinsic safety.

Математическая модель расходных характеристик паротурбинных установок

A large number of generating equipment installed at thermal power plants (TPPs) operate at the limit of their fleet life resource or beyond it. Malfunctions and defects occur during the entire period of operation of steam turbine plant (STP) of TPPs. It causes performance degradation of efficiency, reliability, and maneuverability of STP. Thus, the methods to provide monitoring over the technical position of the elements and/or functional units of steam turbine plant are to be applied. Hence, special attention is to be paid to the development of methods to monitor the technical position and diagnostics of generating equipment of TPPs. The methods are based on a mathematical model of flow characteristics of steam turbine plants. It allows us to consider the effect of changes in the open flow area of the individual compartments of a steam turbine on the pressure distribution over the flow path. To develop the model, the authors have applied mathematical modeling methods and the balance relations of mass and energy methods. The solution of the equations of the obtained linear and nonlinear systems is carried out by methods of computational mathematics. Calculation of thermodynamic parameters of the coolant is carried out based on tables of properties of water and water vapor and software for their description. A mathematical model of a steam turbine plant has been developed. It represents a set of linear and nonlinear algebraic equations that consider the flow discharge characteristics of the steam turbine compartments. Also, it makes possible to assess the technical position and it considers the effect of defects on the pressure distribution over the flow path of the steam turbine. The results of the statistical analysis prove that the model has been recognized adequate under the variation range in the electrical load. The results of the development of mathematical steam turbine plant model can be used to develop intelligent systems to monitor and diagnose power generating equipment of TPPs. Application of these systems allow the management of the TPP to change over from the system of preventive maintenance of equipment to the system of the repair of equipment according to technical position.

Steam turbine power prediction based on encode-decoder framework guided by the condenser vacuum degree.

The steam turbine is one of the major pieces of equipment in thermal power plants. It is crucial to predict its output accurately. However, because of its complex coupling relationships with other equipment, it is still a challenging task. Previous methods mainly focus on the operation of the steam turbine individually while ignoring the coupling relationship with the condenser, which we believe is crucial for the prediction. Therefore, in this paper, to explore the coupling relationship between steam turbine and condenser, we propose a novel approach for steam turbine power prediction based on the encode-decoder framework guided by the condenser vacuum degree (CVD-EDF). In specific, the historical information within condenser operation conditions data is encoded using a long-short term memory network. Moreover, a connection module consisting of an attention mechanism and a convolutional neural network is incorporated to capture the local and global information in the encoder. The steam turbine power is predicted based on all the information. In this way, the coupling relationship between the condenser and the steam turbine is fully explored. Abundant experiments are conducted on real data from the power plant. The experimental results show that our proposed CVD-EDF achieves great improvements over several competitive methods. our method improves by 32.2% and 37.0% in terms of RMSE and MAE by comparing the LSTM at one-minute intervals.

Heat Pump Capacity Selection for TPPs with Various Efficiency Levels

The variety of possible solutions for the integration of heat pumps (HP) into the circuits of generation facilities dictates the need for preliminary selection of the most promising options. Determining the maximally economically efficient HP capacity may be the key limiting factor for the potential range of solutions. The purpose of the study is to analyze the influence of the type of power equipment of a thermal power plant (TPP) on the choice of HP capacity. In the course of the study, we identified factors that can influence the choice of HP capacity. The correlation between the limitation of the maximum capacity of HP (from the point of view of break-even operation in the electricity market) from the electric capacity and the efficiency of the TPP equipment was established. The ranges of HP capacity for the most common types of TPP power equipment in the Russian Federation were determined. The maximum HP capacity for TPPs based on a steam turbine unit (STU) of type K-300-170- 1P was determined. The method proposed in the paper allows limiting the number of circuits options, as well as TPPs and external conditions suitable for the use of HP. Firstly, under the conditions of a given power system and fuel prices, it is possible to determine the type of power equipment of a TPP in combination with which HP can be used. Secondly, under the conditions of a given power system and type of equipment, the maximum fuel price at which HP can be used at thermal power plants can be determined. Thirdly, under the conditions of a given type of equipment and fuel price, it is possible to select an energy system (region) in which it is possible to build a TPP with HP. It was found that increasing the efficiency of thermal power plant equipment contributes to increasing the HP power capacity and expanding the range of external conditions under which the use of HP becomes rational. It was verified that for TPP equipment of a given type, the use of HP is more rational when operating in cogeneration mode. It was found that, all other conditions being equal, an essential factor determining the range of HP capacity is the electric capacity of TPPs.

The main types of wind turbinesgenerators in the power supply system

THE PURPOSE. To consider the problems of protecting equipment of thermal power plants and heat supply systems from internal corrosion. To study the stages of development of domestic deaeration devices and the principles of atmospheric and vacuum deaeration in the framework of the boiler house in Ulyanovsk. To analyze the operation and maintenance of deaerators: DSA-75, AWACS and DV-75 in the boiler house of JSC «Ulyanovsk Cartridge Plant», and in the UMUP «City Heating System».METHODS. When solving this problem, we used an analytical method for evaluating the operation of the DSA-75 atmospheric deaerator and the DV-75 vacuum deaerator.RESULTS. The article presents the main technical characteristics of the atmospheric deaerator DSA-75 and the vacuum deaerator DV-75, and graphical dependencies characterizing the operation of the above deaerators were obtained.CONCLUSION. An analysis of the work of the «AWACS» deaerator showed that this device was never able to take its rightful place as the main and additional deaeration device in the boiler house in Ulyanovsk. Accordingly, the «AWACS» deaerator could not stand on a par with the long-established deaerators developed at CKTI. The authors found that at the present time, at the UMUP «City Heating System» boiler house considered in this article, the water treatment system using the traditional DV-75 vacuum deaerator is well debugged and performs its functions. Thus, high-quality water treatment is ensured in the boiler house.

Justification of the power of the heat pump used in the cooling system of the steam turbine condenser of the CCGT-CHP

THE PURPOSE. Determination of the permissible power of the heat pump (HP) used in the cooling system of the steam turbine condenser for a thermal power plant (TPP) based on double-circuit combined-cycle gas turbine (CCGT).METHODS. Mathematical modeling of the operating modes of a heating CCGT with a HP in the cooling system was used as a research method. The research was conducted using statistical data on technical parameters and economic indicators of CCGT-450, for climatic and market conditions of St. Petersburg. The research of the most characteristic modes of operation of the main power equipment, in the annual context, was carried out. The maximum permissible capacity of the HP, from the point of view of the organization of stable heat supply to the consumer, available low-potential resources and breakeven operation of TPP in the electricity market was determined.RESULTS. It was found that lowpotential energy resources in the cooling system of the steam turbine condenser are formed in significant volumes and the thermal power of the consumer is consistently high, including in summer. Therefore, market restrictions related to the break-even operation of TPP in the wholesale electricity market are the most essential condition determining the permissible level of HP power. It was found that for the object of study, with an average annual electrical capacity of 650 MW, the maximum power of the HP is 160 MW.CONCLUSION. The main factors limiting the permissible level of HP power were analyzed using the example of a real power facility. A direct connection between the maximum capacity of the HP and external economic conditions, as well as the level of energy efficiency of the TPP equipment was established. This approach can be used to select and justify the HP capacity regardless of the location region, the type of power system, the cost of energy resources, market conditions, as well as the type and characteristics of the equipment used.

Determination of average relative capital investment of 30–125 MW combined-cycle plants commissioned at Russian thermal power plants in 2015–2020. Comparative analysis with data obtained in 2010–2014

The present work examines average relative capital investment and fuel consumption for electric and thermal energy supply of the combined-cycle plants having 30–125 MW gas turbines commissioned at Russian thermal power plants in 2015–2020. In this work, we used general calculation methods of average relative capital investments and fuel consumption for the electrical and thermal energy supply using power equipment of thermal power plants. To assess the scope of commissioning gas turbines incorporated into the combined-cycle plants, they were classified into three groups by electrical power: 30–59 MW, 60–99 MW and 100–125 MW. The scope of commissioning gas turbines incorporated into the Russian combined-cycle plants in 2015–2020 was analysed. The average relative capital invest-ment in combined-cycle plants having 30–125 MW gas turbines, as well as the average specific fuel consumption for the electrical and thermal energy supply, were calculated. The calculations were carried out for each part of combined-cycle plants integrated into thermal power plants with a breakdown by seven Unified Energy Systems of Russia. The quantita-tive commissioning of gas turbines is compared for the periods from 2010 to the economic crisis of 2014 and after 2014 to the present: a ~2.5-fold decrease is demonstrated. A preliminary evaluation of the increase in average relative capital investment in combined-cycle plants having gas turbines of the same electric power was performed.

Development of methodology and measures to ensure the reliability of energy systems equipment

THE PURPOSE: The article presents the results of the development of a methodology for the design calculation of reliability and changes in the level of reliability of energy systems, taking into account the influence of control actions based on statistical methods of collection, analysis and models of experimental data processing.METHODS: The system analysis and generalization of experimental data on technological failures of the main equipment of thermal power plants were used in the calculation assessment.RESULTS: The objective function of controlling the reliability parameters of the thermal power plant power equipment is proposed. The approbation of the presented objective control function was performed, which showed the adequacy of the results obtained to assess the reliability of the main nodes and elements of the TPP power equipment.CONCLUSION: The results of the conducted studies show that when determining reliability indicators, it is necessary to take into account the actual technical condition of individual elements and resource-determining functional units of thermal power plant power equipment. The results obtained can be used to develop a methodology for evaluating control actions for calculating the output control parameters and a mathematical model for changing the output characteristics of TPP steam turbines in terms of heat and electric energy generation, as well as at the stage of developing design documentation for the creation of structural elements and practical recommendations in order to extend the service life of power equipment generating systems based on digital technologies.