Efficiency Of Thermal Power Plants Research Articles

Optimizing steam condenser efficiency: integrating logarithmic spiral search and greedy selection mechanisms in gazelle optimizer for PI controller tuning

Steam condensers are critical for maintaining efficiency and stability in thermal power plants by converting exhaust steam back into water. Controlling the pressure within the condenser is essential for optimal performance and operational safety. This paper presents a dynamic model of a steam condenser, with pressure control achieved through a proportional-integral (PI) controller. The PI controller parameters are optimized using the gazelle optimization algorithm (GOA), which is applied for the first time to this system in the literature. Additionally, novel enhancements, the logarithmic spiral (Ls) search with greedy selection, are integrated into GOA to further enhance control effectiveness. The performance of the optimized PI controller is evaluated using nonlinear simulations, which include statistical analysis and fitness function assessments. To validate the effectiveness of the proposed approach, comparisons are made with other widely used optimization techniques. The results reveal that the GOA notably enhances control accuracy and stability, with the enhanced GOA (Ls-GOA) achieving the most significant improvements. This underscores its potential for enhancing steam condenser efficiency in thermal power plants.

Thermal Power Plant Performance Analysis by Estimating Boiler Efficiency via Indirect Method: A Case Study

The performance of power plants is very critical since it is directly related with operating and electricity production costs. Among the other different type of power plants, coal-fired ones have advantages such as reliability and low cost fuel. In this paper, a coal (lignite) fired thermal power plant having capacity of 160 MW is taken into consideration and the impact of condenser pressure, moisture content of lignite, excess air coefficient, efficiency of turbine pressure and heater numbers on power plant thermal efficiency is investigated. It is aimed to determine performance losses of each equipment by means of the thermodynamics and economic analysis. In this scope, it is expected that the power plant operator will be able to evaluate the reduction potential of equipment performance losses and ensure more effective use of the power plants by correctly planning the maintenance and rehabilitation needs and times. In the calculations, the boiler efficiency was determined with EN 12952-15 standard (indirect method) since this method has higher accuracy in coal fired boilers. It is seen that the condenser pressure and excess air coefficient increments have not significant impact on power plant efficiency compared to moisture content of lignite, excess air coefficient, efficiency of turbine pressure and heater numbers. The significant effect is observed for fuel moisture content which rises from 22% to 47% and the power plant efficiency falls from 40% to 28%. The variation of the power plant thermal efficiency in case of failure of heaters is investigated and the power plant efficiency has decreased from 40.17% to 36.09% when the pre-heaters are no longer in to be in use because of any reason. In addition, revenue losses are estimated for each main equipment efficiency reduction for better use of power plant capacities and electricity lowering production costs.

Comparative assessment of global warming potential of gasoline, battery, and hybrid vehicles in India

This study reports a comparative analysis of life cycle greenhouse gas (GHG, CO2-eq.) emissions of three fuel-type vehicles, viz. internal combustion engine (ICEVs), battery electric (BEVs), and hybrid electric vehicles (HEVs), from an Indian perspective. Vehicles in hatchback and compact sports utility vehicles (SUVs) categories were analyzed. GHG emissions in fuel life cycle (well-to-tank and tank-to-wheel) and vehicle life cycle were estimated using data from websites of OEMs and ministries of Government of India, and the GREET software. The vehicle life cycle constitutes a smaller fraction (15–20 %) of total life cycle GHG emissions for ICEVs and HEVs compared to BEVs (∼35 %). The vehicle cycle emissions of BEVs are higher than ICEV and HEV in both categories (52–63 % for hatchback and approx. 45 % for compact SUV). The fuel cycle emissions of BEVs are smaller than ICEV and HEV in both categories (29–34 % for hatchback and 32–40 % for compact SUV). The total life cycle GHG emissions of BEVs were lower than ICEV and HEV (15–17 % in hatchback and 17–25 % in compact SUV category) for the 2023 energy mix in India with a significant share of thermal route. With anticipated doubling of renewable energy sources in India by 2030, the total life cycle GHG emission of BEV will decrease by approximately 20 %. However, sensitivity analysis revealed that BEVs produce higher GHG emissions than ICEVs and HEVs until a minimum lifetime travel distance. Thermal power plant efficiency and battery lifespan also influence BEVs lifetime GHG emissions.

Energy saving scheduling of power and two steam loads for a CHP system consisting of multiple CHP units integrated with steam ejectors

Combined heat and power (CHP) can effectively enhance the energy efficiency of thermal power plants. However, the heat-dominated operation mode restricts the CHP unit's operation flexibility which is essential for the power grid for peak shaving. The double-extraction CHP unit, which cogenerates power and two-pressure steam for industrial or municipal heating users, is typical, complex, and widely applied. The integration of steam ejectors is an effective way to enhance the operational flexibility of the double-extraction CHP unit, which makes the scheduling of power and two steam loads very complicated. Therefore, the scheduling model of a CHP system consisting of multiple CHP units integrated with steam ejectors is developed in this study to achieve energy saving. A reference CHP system with four 1000 MW CHP units with steam ejectors is analyzed, and the operational flexibility and energy consumption characteristics of the units are analyzed. Then, the scheduling of power and two steam loads within a typical day is conducted. The results show that the coal consumption is reduced by 0.65–3.10 t h−1 compared with the original heating mode.

Automation of transportation of vapor of atmospheric deaerator in boiler installations

At present, when energy prices are unstable and periodically rise, enhancing the energy efficiency of thermal power plants, which implies the production of the same or larger amounts of energy with a lower consumption of energy resources, remains an urgent problem in the field of thermal power engineering. Such tasks aimed at reducing the consumption of energy resources for their own needs are quite urgent for manufacturing enterprises that use energyconsuming equipment, in particular steam boiler plants. Steam boiler houses contain a sufficient amount of energyintensive equipment, be it the boilers themselves or atmospheric deaerators, which are used to purify the boiler feedwater from corrosive gases. The article discusses the option of automating the process of closing the vapor during atmospheric deaeration in boiler plants by installing valves with automatic drives on the vapor removal pipelines. The article also analyzes the annual replenishment flow rate of the deaerator, assesses the quality of the condensate supplied to the deaerator, describes the conditions for opening and closing valves with automatic drives, and provides a calculation of the time delay required to remove vapor from the deaerator before closing the valves. A functional block diagram for controlling automatically driven valves is presented and its components are described. Thus, when implementing the described technology, significant savings in production steam spent on the deaerator will be achieved due to the closing of the deaerator vapor, with no chemically purified water supplied to the deaerator. This solution helps to increase the operating efficiency of the entire boiler installation.

Особенности сжигания композиционных водоугольных топлив

Russia has large coal reserves, on the average up to 173 billion tons. Although, the share of coal generation in Russia is relatively small (about 20–22 %), it reaches 65 % in the Siberian Federal District. Russia cannot deny coal, but it is necessary to update and improve energy efficiency of Thermal Power Plants (TPP) and boiler houses that burn coal. Currently, technologies have been developed to produce and use composite coal-water fuel (CWF) with various additives, primarily of organic origin to improve its target characteristics. A study of the characteristics of such coal-water suspensions has proved the promising outlook of their use as fuel in large and small Thermal Power Plants, both from an economic and environmental safety points of view. However, the lack of experimental data on the issues of combustion of composite coal-water fuel in bench-scale and semi-industrial conditions hinders the further development of CWF technology. Thus, it is relevant to study the features of combustion of composite coal-water fuels from coals of varying degrees of metamorphism. To prepare experimental batches of composite CWF, raw coals and coal slurries of various stages of metamorphism (grades D, SS, T) have been used. They were burned in a bench-scale semi-industrial plant. The research results have been processed using the methods of mathematical statistics and regression analysis. The influence of mechanical activation of CWF on the viscosity and temperature of its ignition and combustion has been established. The features of combustion of composite coal-water fuel using pneumomechanical injectors of two types are determined. The composition of harmful emissions during the combustion of CWF has been determined. The possibility to use composite coal-water fuel to ignite high-power boilers has been established. It has been proved that the combustion of CWF is environmentally safer compared to the combustion of coal and other types of fuel.

Design of a Decision Support System for Power Plant Thermal Efficiency Management at PLTU X

Efficiency management is one of the important pillars of the asset management system implemented at PLTU X based on PJBS guidelines to manage the power plant reliably and efficiently, which can support realising the company's vision of becoming a trusted power plant manager in Southeast Asia. As with efficiency management functions in other lines, the aim of power plant efficiency management is also to reduce production costs and ensure that the plant can operate efficiently all the time by controlling thermal losses in the power plant cycle. Determining efficiency management recommendations is very necessary to minimise the level of thermal losses that occur in the power plant's thermal cycle after evaluation. There is a series of evaluation processes that must be carried out to determine recommendations for optimising generator efficiency management; however, the process is currently still manual and takes a long time. With the advantages of a decision support system, which is usually used in determining systematic strategic decisions, it is hoped that this design can help engineers determine steps based on recommendations produced by the system precisely and in real-time so that they can be executed immediately to increase the efficiency of power plants even more. optimal.

Performance evaluation and operation optimization of a combined heat and power plant integrated with molten salt heat storage system

Combined heat and power is an effective way to enhance the energy efficiency of thermal power plants. The solar and wind power are intermittent, and dispatchable power sources are critical to balance the supply and demand sides. To facilitate the high penetration of renewable energy, combined heat and power (CHP) plants should provide more and more peak shaving services for the power grid. The thermal energy can be stored in and released from the molten salt heat storage system (MSHSS). The integration of MSHSS can enlarge the adjustable range of the power load of CHP plants, so it is a potential way to enhance the operational flexibility of CHP plants supplying industrial steam and power. In this study, the MSHSS integrated within CHP plants are proposed, which store a part of sensible heat energy carried by extraction steam before supplying to industrial users. The heat storage capacity dominates the flexibility enhancement, and indicators to evaluate energy performances of the proposed system are defined. Moreover, models for the operation optimization of CHP plants integrated with the MSHSS are developed, and a case study of a 350 MW CHP unit is conducted. When the reheat steam is extracted to supply to industrial steam, the maximum and minimum adjustable power loads can be increased and decreased by 17.13 and 12.01 MW, respectively with the integration of the MSHSS. Moreover, during the peak, flat, valley time of reference day, the heat supply coal consumption rates are 73.94, 74.19 and 81.03 kg t−1,respectively. With the operation scheduling of CHP plant integrated with MSHSS, the MSHSS with reheat steam as heat source show the lowest coal consumption rate as 1553.79 ton/day.

Preliminary Design of Electric Part of Thermoelectric Unit in a Power Plant

With the rapid development of society, people’s awareness of environmental protection continues to strengthen, countries also pay more and more attention to environmental protection, whether from the national policy or from the green development of enterprises in the future, the improvement of power plant operation efficiency is imperative. Among them, improving the operation efficiency of thermal power plants is the top priority, and it is also an important link of national economic transformation. The design of electrical part is an important part of improving the operation efficiency of thermal power plants. 2x300MW thermal power plant is designed, including the power plant electrical main wiring design, plant power design, the main circuit of the power plant short-circuit calculation, and it choose the electrical stability and thermal stability of the better electrical equipment. The short circuit calculation of the main circuit of the power plant is carried out and preliminary planning of the secondary circuit scheme is made. A power plant with higher operating efficiency is designed. While improving the operation and economic efficiency of the power plant, it also ensures the reliability, stability and economy of the power plant.

ANALYSIS OF THE MAIN APPROACHES TO THE ASSESSMENT OF THE CONDITION OF TPP AND NPP EQUIPMENT

The materials of the article analyze the current state of the energy industry in Ukraine and the countries of the world and analyze the ways to increase the efficiency of thermal power plants and nuclear power plants. The elements of the power unit can be affected by aging processes that occur over time or as a result of long-term use. The negative impact of aging can lead to the degradation of the element, namely to the deterioration of its reliability and, as a result, the safety of the power unit as a whole. The development and implementation of measures to mitigate aging processes and to ensure reliable operation of elements during the reassigned resource period is a mandatory type of activity for managing the aging of thermomechanical equipment and pipelines.Monitoring of the technical condition of the elements is performed by monitoring the established parameters and characteristics that determine the technical condition of the elements, during their operation, during tests, measurements, operational control of metal, repairs and maintenance of the elements. Monitoring should be carried out systematically throughout the entire life of the power unit. In turn, technical diagnostics monitors the current state of all elements, detects abnormal conditions, determines the causes of their appearance, which allows you to assess the situation and take measures to eliminate them. The purpose of the article is to analyze the main approaches to assessing the state of energy equipment of thermal and nuclear power plants.

Повышение эффективности использования твердого топлива на промышленных ТЭЦ

Currently, in this country solid fuel at industrial thermal power plants, as a rule, is burned by a layer or flaring method in boilers with generation of steam which is directed to a steam turbine. This technology of generating thermal and electrical energy is characterized by relatively low efficiency and significant emissions of pollutants into the atmosphere. At the same time, the use of solid fuel in industrial energy with its preliminary gasification can significantly increase the efficiency of electricity generation and at the same time reduce the negative impact on the environment. The results of an analytical comparison of two schemes to use solid fuel in industrial energy are used as the material of the research. These two schemes are a traditional scheme and an alternative one based on its preliminary gasification. In this paper, to assess the effectiveness of the schemes under consideration, the scientific methodology of system analysis is applied. It allows us to consider any energy object as a unified system consisting of interrelated elements. The system analysis is carried out based on mathematical modeling of the technological process to obtain thermal and electrical energy. A complex balance mathematical model of an industrial thermal power plant with preliminary coal gasification is developed. The results of calculation using a mathematical model have shown that the construction of industrial combined‒cycle thermal power plants with preliminary coal gasification instead of traditional steam turbine ones will increase the key indicator of the energy efficiency of thermal power plants, coefficient of fuel utilization from 60 to 74 %. Based on the methodology of system analysis, an optimal thermal scheme of an industrial combined-cycle thermal power plant with preliminary coal gasification has been developed. Numerical values of the basic operating conditions of the thermal power plants and energy efficiency indicators have been determined using a mathematical model. The use of solid fuel at industrial thermal power plants with its preliminary gasification is a very promising direction to develop industrial energy in Russia since this method to extract the bound chemical energy of solid fuel can significantly increase the fuel utilization coefficient and the production of electrical energy and at the same time reduce emissions of contamination material into the atmosphere

Economic evaluation of hydrogen production in second and third units of Bushehr nuclear power plant regarding future need of nuclear fission technology

Today, the most important challenge for hydrogen production is the use of suitable energy source for sustainable production. The dual use of nuclear power plants allows them to expand into other markets by eliminating greenhouse gas emissions from processes such as hydrogen production. The significance of this matter especially in countries with ongoing new nuclear power plants is high and shows the future need for nuclear fission technology. In this paper, an economic assessment of hydrogen production in the second and third units of the Bushehr nuclear power plant (BNPP) with the Hydrogen Economy Evaluation Program (HEEP) is carried out and a comparison of CO2 emission in nuclear and non-nuclear methods of hydrogen production is presented. Most nuclear reactors, including Advanced Pressurized WaterReactor (APWR), High Temperature Gas Reactor (HTGR), and Water-Water EnergeticReactor (WWER), can be used as a source of thermal and electrical energy for the process of hydrogen production. In this research, hydrogen production processes based on the Conventional Electrolysis (CE), High Temperature Steam Electrolysis (HTSE), and Sulfur-Iodine (SI) Process using different storage and transportation options are compared to choose the cost-effective method for coupling with the WWER1000 reactor. Hydrogen production, thermal energy, and electricity costs have been calculated and explained in detail. The results showed that the cost-effective option for hydrogen production is using the High Temperature Steam Electrolysis (HTSE) method, Compressed Gas (CG) storage, and pipeline transportation, by 2.88 $/kg. Also, applying this method to produce hydrogen, the nuclear power plant thermal efficiency, and the hydrogen plant efficiency are kept in the best possible conditions by 51.98% and 58.21%, respectively.

Simulation modelling of sampling and replacement of coal suppliers for thermal power plants

This paper embarks to the persistent suboptimal coal quality issues experienced in thermal power plants that hinder operational efficiency and sustainability. The research is divided into three main segments: formulation of a transport problem, creationof a coal supplier selection model, and construction of a MATLAB Simulink® simulation for detecting and refusing low-grade coal. The proposed supplier selection model, important for thermal power plants, considers factors such as potential transport delays and the necessity of reserve refueling to prevent fuel shortages. This model is expected to decrease fuel shortages and enhance the reliability and efficiency of thermal power plants. Additionally, a coal quality detection model has been developed using a sampling approach based on the Cochran formula, aiming to increase defect detection accuracy, thus reducing the likelihood of utilizing poor-quality coal. The model's unique feature is its dynamic adjustment of coal sample selection based on combustion results, enabling real-time response to coal quality inconsistencies. Upon detecting poor-qualitycoal, the power plants promptly switch to an alternate supplier, minimizing operational disruptions. The validity of the models was confirmed via simulation on various examples

Jetty Extension Study Due to Addition of Power Capacity on Thermal Water Dispersion at PLTGU Grati Pasuruan

PLTGU (Gas and Steam Power Plant) is a combination of gas power plant and steam power plant. PLTGU requires a cooling water systems during its operational life. The required amount of cooling water will increased along to increased power capacity of power plant. This project contains jetty extension study due to the addition of power capacity on thermal water dispersion at PLTGU Grati, Pasuruan. The results show using Delft3D hydrodynamic model, The alternative model showing quite good performance decreased temperature of cooling water on average 0.7975 oC at inlet canal. But it only need 2.5 oC increase of seawater temperature to decrease 0.33% efficiency, so it might change nothing to thermal power plant efficiency compared to the model result. Considering to the increasing risk of sedimentation rate, this alternative might be poor layout but further research needed. Still the best choice is on existing jetty design.

Improving the Thermal Power Plant Efficiency through the Use of Solar Technologies

The demand for energy is growing rapidly with the development and improvement of the standard of living in the world. The interaction between energy generation facilities and the environment is a topic that requires close attention, since these two components have a significant influence on the human existence and progressive growth of productive forces. Over the past few decades, the main attention has been paid to research aimed at improving conventional power plants, reducing harmful emissions into the environment, and introducing renewable energy sources. One of the ways to develop thermal power plants and reduce the impact on the environment is hybridization of solar technologies with thermal power plants. An overview of solar technologies used in the energy sector is given. A hybrid thermal power plant (TPP) aided by solar technology, known as Solar Aided Power Generation (SAPG), is briefly described. A hybrid model of an SAPG plant is considered, and the efficiency of such power plants is analyzed. The conditions of the People Republic of Bangladesh were chosen for the calculations. Information on the current state of the Bangladesh energy sector, on the climatic features of the country, and on the potential for introducing hybrid solar technologies in it is given. The power plant model was simulated using the Thermoflex software produced by the Thermoflow company. The calculation results have shown that the SAPG plant annually generates by about 25% more power than the standalone concentrated solar power plant.

Experimental Analysis of CFBC Boiler and AFBC Boiler with Different GCV, Boiler Loads and Excess Air

Abstract: The main motive of this study is to experimental analysis of the Atmospheric fluidized bed combustion boiler and Circulating fluidized bed combustion boiler with different gross calorific value of coal, boiler loads and excess air. For this analysis, use textile waste as a primary fuel and calculate GCV with help of bomb calorimeter. Conduct energy calculation of the overall plant and determine the efficiencies and energy losses of all the major components of the thermal power station. The study was carried out at Thermal power station of Industry Yarns at Mandideep and boiler section of thermal power plant is considered for the purpose of exergy analysis. The boiler of a power plant is the most effective section in eliminating exergy. Calculate the efficiency of CFBC and AFBC Boiler with different GCV of Textile waste and it is clearly shows that efficiency of CFBC boiler is higher than AFBC boiler in same GCV of textile waste. The present investigation show results of 30 mw power plant. Experiments were conducted using 0%, 20 %, 30% and 40% of excess air and 65%,70%,75%,80%,85%,90%,95% ,100% boiler loads. In the present investigation boiler house gives the best results at 0% excess air with maximum boiler load as far as the boiler efficiency (75.2%) are concerned. 65% boiler load With 0% excess air the boiler efficiency is found to be maximum (75.2%), which gives minimum heat loss. Without excess air AFBC boiler is not capable to burn low grade fuels show it is clear that for low grade fuel maximum efficiency of thermal power plant achieved by CFBC boiler because low grade fuel completely burns with 0% excess air.

Ensuring Energy Efficiency of Thermal Power Plants and Heating Networks by Means of Digital Transformation

The article deals with the issue of state-of-the-art development of the energy industry enterprises of the Russian Federation with the introduction of innovative digital technologies. The relevance of the research on the chosen problem is due to the transformational processes in the energy industry, that occur under the influence of digital economy introduction and the development of digital technologies. A study of the current situation and features of domestic energy industry has been carried out to identify the main factors of low efficiency that encourage energy companies to digital transformation. One of the key directions of improving the production activities of energy sector enterprises of the Russian Federation for the development of energy efficiency management system due to digitalization processes is considered. Practical examples of the creation, implementation and development of digital technologies at existing thermal power plants and thermal networks aimed at reducing the energy intensity of electric and thermal energy production, the transition from a system of scheduled preventive repairs to repairs according to the actual condition of equipment: digital counterparts of thermal power plants, digital nodes of thermal networks, predictive analytics systems and remote monitoring. The purpose, functionality, principles and models of work, the effects obtained from the introduction of digital systems, promising directions for the development of digital technologies are considered. A comparative analysis was carried out to identify the advantages and disadvantages of foreign and domestic systems of digital doubles and predictive analytics developed under the sanctions of unfriendly countries. The key barriers hindering and constraining the processes of full-scale digital transformation of energy industry enterprises are presented. The necessary conditions and motivating factors of state support of domestic business for the successful implementation and development of digital technologies have been established.

MODERN TECHNOLOGIES FOR INCREASING THE ENERGY AND ENVIRONMENTAL EFFICIENCY OF ENERGY PRODUCTION

The problems of energy efficiency of energy production along with improving the environmental safety of enterprises are becoming increasingly relevant. One of the ways to solve these problems is the implemention of effective technologies, which include microflare incineration technology (MIT-technology) of gaseous fuels. The use of MIT- technology, in addition to a significant reduction in harmful emissions into the atmosphere, can simultaneously increase the energy efficiency of thermal power plants.
 A significant positive effect can also be achieved by using contact energy exchange plants. A striking example of such a gas-steam plant “Aquarius” the operation of which exceeds the efficiency of gas turbine plants by 10-12% with a simultaneous significant decrease in the concentration of toxic nitrogen oxides NOx and carbon monoxide CO in flue gases.

Sustainable power generation through decarbonization in the power generation industry

Due to using fossil energy resources, power generation is the most important factor of pollution and greenhouse gas emissions. Considering the importance of the issue, seven scenarios for decreasing greenhouse gas emissions in the power industry, including the development of renewable energies, energy efficiency in thermal power plants, and decreasing the emission of carbon according to international agreements, and the creation of sustainable power generation systems, were defined and evaluated technically, economically, and environmentally. In the current study, an optimization model for long-term power generation planning was used for two concepts of supply and demand. The results of comparing the scenarios showed that the development of renewable power plants was not solely a suitable and optimal way for decreasing greenhouse gas and carbon emissions. The strategies for improving efficiency in thermal power plants, including the development of combined cycle power plants and the repowering of steam power plants, are more suitable options for implementation, considering the constraints of the problem. Therefore, eliminating the existing circumstances and employing the combined scenario while considering the objectives of the study should be the only strategy for decarbonization in this industry, with the minimum cost and minimum rate of emission. By decreasing the share of thermal power plants, decreasing fuel demand, and increasing the share of renewable power plants to 20%, the combined scenario would decrease pollution and greenhouse gas emissions by up to 77.6 million tons of carbon dioxide, as well as the environmental costs up to 1894.5 million dollars, compared to the basic scenario up to 2030. Moreover, paying attention to the management strategies of a demand concept seems necessary from an economic viewpoint, in addition to other presented strategies.

Review of Closed SCO2 and Semi-Closed Oxy–Fuel Combustion Power Cycles for Multi-Scale Power Generation in Terms of Energy, Ecology and Economic Efficiency

Today, with the increases in organic fuel prices and growing legislative restrictions aimed at increasing environmental safety and reducing our carbon footprint, the task of increasing thermal power plant efficiency is becoming more and more topical. Transforming combusting fuel thermal energy into electric power more efficiently will allow the reduction of the fuel cost fraction in the cost structure and decrease harmful emissions, especially greenhouse gases, as less fuel will be consumed. There are traditional ways of improving thermal power plant energy efficiency: increasing turbine inlet temperature and utilizing exhaust heat. An alternative way to improve energy efficiency is the use of supercritical CO2 power cycles, which have a number of advantages over traditional ones due to carbon dioxide’s thermophysical properties. In particular, the use of carbon dioxide allows increasing efficiency by reducing compression and friction losses in the wheel spaces of the turbines; in addition, it is known that CO2 turbomachinery has smaller dimensions compared to traditional steam and gas turbines of similar capacity. Furthermore, semi-closed oxy–fuel combustion power cycles can reduce greenhouse gases emissions by many times; at the same time, they have characteristics of efficiency and specific capital costs comparable with traditional cycles. Given the high volatility of fuel prices, as well as the rising prices of carbon dioxide emission allowances, changes in efficiency, capital costs and specific greenhouse gas emissions can lead to a change in the cost of electricity generation. In this paper, key closed and semi-closed supercritical CO2 combustion power cycles and their promising modifications are considered from the point of view of energy, economic and environmental efficiency; the cycles that are optimal in terms of technical and economic characteristics are identified among those considered.