Showing papers on "Thermal power station published in 2023"

Operating Modes Optimization for the Boiler Units of Industrial Steam Plants

Abstract: The free market forces energy-intensive industrial enterprises to continuously compete. A possible competitive advantage for such enterprises is reducing the finished products cost. This may be achieved by reducing the share of energy in this cost, including by rationalizing the use of energy resources. This study develops a system for the automated analysis and calculation of feasible boiler unit loads, defined according to the criterion of the minimum cost of live steam in a separate steam plant pipeline. The calculations consider the balance limit on the steam, the boiler unit’s wear and tear, performance specifications, and economic indicators of fuel consumption in the calculation. The software also defines the optimal fuel mix composition when forecasting the operating modes of the power plant boiler units in real-time mode. The calculation algorithm is based on the dynamic programming technique combined with the sequential equivalenting method, which ensures the convergence of calculations. When a steam plant model is developed, much attention is paid to the thermal scheme and technical and economic specifications of boiler units. In the system, the boiler models are set as a table containing the ratio between the boiler unit’s steam capacity and energy consumption while considering the cost of a ton of live steam with the specified parameters. The key economic effect of implementing the system is determined by reducing the fuel cost due to its rational redistribution between the power plant boiler units. Implementing the system allows the reduction of energy costs by 1.4%.

Radioactivity in soil and coal samples collected from the vicinity of the coal-fired thermal power plant and evaluation of the associated hazard parameters

Abstract: This research assesses radioactivity in soil and coal samples around the Barapukuria coal-fired thermal power plant using a high-purity germanium detector. The range of activity of 226Ra, 232Th, and 40K in the studied soil samples were 14–75, 16–112, and 132–460 Bqkg−1, respectively and the respective activity in coal samples ranged from 14–30, 16–39 and 72–182 Bqkg−1. The majority of the hazard indices (absorbed dose rate, gamma index, effective dose and excess lifetime cancer risk) were higher than the world average, which shows that long-term exposure to terrestrial ionising radiation is not safe for coal miners and the local community. The presence of minerals like monazite and zircon, granitic type parent rock, bottom ash discharged adjacent on lowlands, fly ash deposition, different geochemical and physicochemical properties, dominant wind directions, the artificial contamination, meteorological conditions, leaching caused by rainwater- may have a crucial influence on NORM distributions. The quantitative results of this study have important implications for planning a larger and more modern coal-fired power plant, and this study’s findings inspire municipal officials to restrict and monitor the release of fly ash nearby coal-fired power plants. In addition, it is essential to monitor the health of individuals (workers and locals) near the power plant.

Multi-Domain Modeling and Analysis of Marine Steam Power System Based on Digital Twin

Abstract: The marine steam power system includes a large amount of thermal equipment; meanwhile, the marine environment is harsh and the working conditions change frequently. Operation management involves many disciplines, such as heat, machinery, control, electricity, etc. It is a complex multi-discipline physical system with typical nonlinear, multi-parameter, strong coupling characteristics. In order to realize the health management of a marine steam power system, based on digital twin technology combined with the Modelica language, modular modeling, etc., this paper conducts in-depth research on the multi-domain modeling of the marine steam power system, characteristic analysis of variable working conditions, fault simulation, etc. The analysis results show that the dynamic response trend of the model is consistent with the actual operation, the error of the main steam flow at 1800 s is the largest and is −4.9%, and the error of the main steam flow, steam turbine output power, cooling water outlet temperature and other key parameters is within ±5%. Virtual reality mapping between the digital model and the physical equipment is realized, which lays a foundation for mastering the dynamic characteristics of the marine steam power system.

Performance Analysis of a 300 MW Coal-Fired Power Unit during the Transient Processes for Peak Shaving

Abstract: A simulation model based on Dymola modelling was developed to investigate the dynamic characteristics of automatic generation control (AGC) for variable-load thermal power units in this study. Specifically, a 300 MW unit from a power plant in northern China was used to verify the model’s validity in steady-state processes and to analyze the behavior of the main thermal parameters under different rates of load changes. The economic performance of the unit under different rates of load changes is also analyzed by combining the economic indexes of “two regulations” in the power grid. Results indicate that as the rate of load changes increases, boiler output, main steam temperature, reheat steam temperature, main steam pressure, and working temperatures of various equipment fluctuate more intensely. Specifically, at a rate of load reduction of 2.0% Pe MW/min, the maximum deviation of the main steam temperature can reach 7.6 °C, with the screen-type superheater experiencing the largest heat exchange. To achieve a balance between safety and economics for the unit, the rate of load raising should not exceed 1.2% Pe MW/min, and the rate of load reduction should not exceed 0.8% Pe MW/min. This paper applies the covariance index and AGC assessment index of the thermal power unit load control system to the established dynamic simulation model to supplement the AGC assessment index in the “two regulations”, and to provide a flexible and reasonable system evaluation result for field operators to refer to, so as to improve the economics of the system on the basis of safety.

Prediction of carbon capture and sequestration (CCS) technology in a 125 MW tangentially coal-fired subcritical thermal power plant for retrofitting in Bangladesh

Abstract: The main objective of this study is to assess the use of carbon capturing and sequestration (CCS) technology in the existing plant to reduce the emissions leading to retrofitting. A typical 125 MW tangentially coal-fired Barapukuria Thermal Power Plant (BTPP), Bangladesh has been scrutitinized considering air-firing (existing) and five different oxy-firing (OF) cases have been numerically investigated. For predicting the particle flow, radiative heat transfer and turbulence effects, discrete droplet method (DDM), discrete transfer radiation method (DTRM) and k–ϵ model is considered respectively. For homogeneous reaction for the devolatilization and heterogeneous reactions for the char oxidation process, a two steps reaction mechanism is considered. Model has been validated by comparing the predicted flue gas temperature against the plant data at different positions of the furnace and reasonable agreement have been observed. This study assessed the flow characteristics, thermal behavior and species generations of the selected plant under 80% fuel loading. It is predicted that with the increase of cases from air-firing, level of oxiding elements are increasing in the main combustion zone due to enriched O2 level leading to complete combustion of the particles. It is also found that for OF 31 case, level of CO2 is close to the air-firing case. it has been found that wall temperature is comparatively higher for 100% loading and comparatively lower for 50% loading for almost all similar type of air or oxy-firing conditions. For 100% load, the wall temperature has been reached around 2900 K for OF31 case. It is predicted that air operation equivalent to oxy-firing have been found at < OF 30+ % (Flame temp), at = OF 30+ % (Convec Heat transfer) and at > OF 30+ % (radiative Heat transfer) respectively.

Grey Water Footprint of Thermal Power Plants in Ecuador

Abstract: M.G

Power Plant Performance Analysis on Variations of Generator Loading at Ombilin Coal Fired Steam Power Plant Unit 1 (2x100 MW)

Abstract: Abstract— Steam Power Plants are classified as thermal plants that convert chemical energy in fuel into electrical energy. In an effort to increase the effectiveness of the work of the plant, there needs to be proper planning for its operations, this is important because it directly affects the operational costs incurred by the plant. This journal aims to determine the effect of changes in load or variations in generator loading on power plant performance, both efficiency, heat rate and production costs of electricity generation and to identify the magnitude of the decline in the thermal performance of the generator, as well as determine the causes and parts of the plant whose performance level decreases compared to optimal conditions. The method used to calculate the efficiency and heat rate is the “Direct Method”, namely by directly comparing the input energy with the electrical output produced. The data used in this study is the “Power Plant Performance Test” data. The results of this study get the most optimal conditions when loading 93.39 MW Net with efficiency 34.693%, heat rate 2475,445 kcal/kWh and electricity production costs 413,297 Rp/kWh. The conclusion of this study is that plant performance is getting better at high loads. Keywords: Thermal efficiency, Heat Rate, Electricity Production Cost, and Steam Power Plant

The effects of mining methods and coal quality on power generation cost in turkey

Abstract: In this paper, the emphasis was given on coal as being the most important energy raw material in Turkey. The additional electricity can be produced by improving the low capacity utilization rate of thermal power plants. An evaluation has been made for the purpose of classification of coal fields on economic feasibility basis with respect to the power plant development by considering the possible operational costs for electricity generation [1].

Cost and Benefit Analysis of CCUS Application for Thermal Power Units in The Context of Clean Energy Market

Abstract: In the context of the clean energy market, we propose a CCUS retrofit for thermal power units in order to solve the problem of high carbon emissions, which refers to carbon capture, utilization and storage. In order to provide more feasible references for enterprises to invest in CCUS projects, we summarised and analysed the costs and benefits of CCUS application for thermal power units and its influencing factors, and used a provincial thermal power unit as a typical case for analysis and calculation. The conclusion is that if the CCUS project is retrofitted in 2022, the benefits are expected to cover the costs between 2039 and 2040, and the carbon capture costs represent the highest proportion of the expenditure costs over the life of the project.

The Carbon Footprint Reduction Related to Domestic Heating Using Thermal Power Plant Waste Heat

Abstract: The carbon emissions created using fossil fuels for energy are the first place the carbon to the environment. Thermal power plants that burn coal or natural gas provide a significant part of this energy. It does not seem possible to avoid thermal power plants in the short term in future policies regarding energy. Thus, using the waste heat of these power plants for domestic heating to reduce carbon emissions for energy production also decreasing the global climate crisis is a critical practice. In terms of reducing the carbon footprint and the adverse effects of thermal power plants these practices are necessary steps. In this study, two scenarios were created to reduce the carbon footprint of heating based on waste heat from the natural gas thermal power plant in Sakarya. This is considered with the district heating system in houses. For domestic heating, natural gas is used in the first scenario, coal is used in the second scenario, and the carbon footprint is determined. Emissions from the power plant's use of coal and natural gas are also determined. District heating using waste heat and its process and installation cost was also analyzed. As a result, it has been revealed that there will be a carbon reduction of 461,161.2 tons/year CO2e when natural gas is not used for domestic heating and 605,159.6 tons/year CO2e when coal is not used. All this is possible by the use of waste heat. The annual carbon emission of the power plant using natural gas was found to be 1,263,260.8 tons/year CO2e, and the emission value was found to be 9,682,554 tons/year CO2e when coal was used in the power plant. The study results will guide policymakers to reduce the carbon footprint of heating using district heating systems, both in Turkey and developing countries where fossil fuel thermal power plants are used.

Two-layer optimization model of joint peak shaving of energy storage and thermal power units

Abstract: Against the backdrop of large-scale wind power generation solar energy networking, the problem of peak regulation of power systems is becoming more prominent day by day. Under the premise of considering sufficient absorption of wind power generation and photovoltaic power, the text uses stored energy to assist the depth control peak of the thermal power generation unit, constructs a two-layer optimization model of the fire storage association regulation peak, and optimizes the storage energy charging and discharging plan with the goal of minimizing the valley difference between the load peaks. The lower layer aims to minimize the peak adjustment cost and carbon emission of thermal power generation unit, and optimizes the combined adjustment of thermal power generation unit by considering the difference in peak adjustment depth and cost of different units. The simulation revealed that the addition of an energy storage system reduces the peak adjustment cost of thermal power generation unit.

The Preliminary Study of Potential Contamination Related to the Combustion of Coal in Thermal Power Plant*

Abstract: In order to obtain the basis for understanding the behaviour and impact of the potentially toxic elements in the environment as consequence of the coal combustion in thermal power plant, about 3,000 square kilometer inland area around a thermal power plant in Hebei Province was investigated by the authors. The samples of fly ash, slag, coal and soil collected in the power plant and around the plant were analyzed by means of neutron activation analysis, X-ray diffraction analysis and SEM. Some elements like Fe, Ca and K enrich in fly ash and slag, the content of Sb is the lowest. The contents of harmful elements such as As, Cr, U and Th are not very high. The main combusion product are glass, mullite, spinel and aluminosilicate. The ratios of ER/CER and SER/CER of the most of elements are beyond 1, making it possible for the trace elements in slag and fly ash to migrate to the surrounding area. The leaching solutions of the soil collected were analyzed by the ICP-MS to acquire the concentration of the elements they contained. In terms of the leaching results, some elements like Ba, Bi, Ce, Co, Cr, Cu, Mo, Sr, V, Y, Pb remove easily; some elements like As, Cs, Hf, Nd, Rb, Sn, Th, Ti, Zr are difficult to migrate. The leaching result of the soils indicates that migration of the elements has no inevitable relationship with the enrichment of the elements in the whole area. Though the contour line and FSF of the elements which derived from the leaching result show that elements like Bi and Rb enrich in some area, it may attribute to their natural conditions, which can not be sure that chimneys of the power plant or other similar ways to give rise to. Only Cd, As, Cu, Pb, Cr, Zn and Ni are compared with the soil standard quality of our country as a result of shortage of our soil standard nowadays. Only the content of Cd are beyond the standard. By means of FSF (fractal structure factors), the distribution of each element in this area was quantitatively illustrated. Moreover, a series of element contour graph were drew. These two kinds of analytical technique made just the same conclusion.

Study on Calculation of Inlet Steam and Inlet Water Flow of Drain Pump of Low Pressure Heater

Abstract: In the traditional drainage system of low pressure heater of thermal power unit, the measuring point of drain pump is usually added to directly measure the water and steam flow of low pressure heater of drain pump with instruments. This method is time-consuming and labor-intensive, and the measurement results are affected by many environmental factors. In order to solve this problem, this paper proposes an automatic calculation method based on the principle of heat balance.

Application modelling of intelligent diagnosis for thermal cycle system

Abstract: In order to solve the problem of intelligent fault diagnosis of thermal system of thermal power unit, the application modelling of intelligent diagnosis of thermal cycle system is proposed. This paper first filters the influence of the change of valve opening of steam turbine on the performance index under the condition of constant power, and qualitatively analyzes the actual change of the performance index compared with the reference working condition when the component fails, so as to eliminate the mutual influence between the components. Then, the selection principle of thermodynamic parameters is determined, the irreversible loss in the structural theory of thermal economics is introduced as the performance index, and the model is used to quantitatively calculate the change of performance index of each component under fault conditions to diagnose the failed component. Finally, APROS simulation software is used to simulate various fault conditions of 330 MW units in a power plant. The experimental results show that the recognition accuracy of the monitoring system designed in this paper can reach 98.33%. In conclusion, the method in this paper proves the feasibility of intelligent fault diag?nosis of thermodynamic system network.

Trends in Improving Automatic Control and Regulation Systems of the Thermal Power Plants

Abstract: Relevance of the article is determined by the need to improve power and dynamic performance of the thermal power plants and indicators of their fuel efficiency and toxicity of the exhaust gases. An integral part of these facilities are the automatic control and regulation systems that ensure coordination of the elements and systems of the combined thermal and power facilities in a wide range of their operating modes. The most important criteria in such elements and systems coordination are the indicators characterizing toxicity of the exhaust gases. Currently, thermal power plants based on the piston and combined internal combustion engines are widely used. Main areas of improving thermal power plants with the internal combustion engines and their automatic control and regulation systems were analyzed. For example, expanding their functionality including the exhaust gas purification systems control and the use of thermal power plants in adaptation to operate on the alternative fuels; improving the quality of control and regulation processes and minimizing the share of unsteady operating modes of the thermal power plants. Current level of systems for automatic control and regulation of the thermal power plants was evaluated. Working processes of the internal combustion engines and their systems were studied. The most important systems of the combined thermal power plants with internal combustion engines, such as fuel supply, air supply, gas distribution, cooling, lubrication, purification and exhaust gas recirculation systems were considered. The need was also noted for comprehensive optimization of the engine parameters and its main systems

Influence of fouling of heat-exchange surfaces of condensers of steam turbines on the carbon oxide emissions

Abstract: According to the strategy of environmental development of Ukraine until 2030, in order to increase the Environmental Performance Index (EPI), it is planned to reduce the energy intensity of GDP. One of the most polluting industries is the thermal power industry, and therefore reducing the emission of harmful gases, in particular nitrogen dioxide, is an important environmental problem. The share of electricity production by thermal power plants and thermal power plants in the electric power complex is significant, which leads to environmental risks due to large emissions and discharges of harmful substances by these enterprises into the environment. The magnitude of such emissions depends on the efficiency of the circulating cooling systems, which affects the rational use of fuel and water resources and, accordingly, the state of the environment. Increasing the temperature of the exhaust steam by reducing heat transfer through the contaminated heat exchange surface increases the pressure in the condenser of steam turbines and reduces the power of the turbine, which increases fuel consumption and increases the amount of emissions of harmful substances. One of these emissions is nitrogen dioxide, which is a harmful toxic compound and is classified as a greenhouse gas. The Purpose of the work is to calculate oxide carbon emissions depending on the thickness of the deposited layer on the heat exchange surface of the condensers of steam turbines of TPP. The concept of a particle of harmful emissions associated with the emergence and growth of a layer of pollution of the heat exchange surface of the condensers of steam turbines of TPP, expressed in fractions of a unit, is introduced, and an analytical expression is obtained for this value. Based on the theories of fuel combustion, heat transfer, as well as the concept of a part of harmful emissions associated with the emergence and growth of a pollution layer, the dependence of the amount of harmful emissions associated with fuel combustion at TPPs on the thickness of the pollution layer of the heat exchange surface of steam turbine condensers is obtained. Keywords: environmental pollution, thermal power plants, carbon monoxide, heat exchange surfaces.