Coal-fired Thermal Power Plants Research Articles

Energy efficiency as a driver of the circular economy and carbon neutrality in selected countries of Southern Europe: a soft computing approach

BackgroundThe main goal of the paper is to define the level of energy efficiency in the economies of selected countries in the Balkan region that have opted for the EU Green Deal, a circular economy, and a transition to carbon neutrality. Energy efficiency, as a determinant of carbon neutrality, was selected as an indicator for analysis because it records particularly unfavorable indicators in the region under observation. The research was carried out on a sample of seven Balkan countries and their surrounding areas. An initial qualitative analysis was followed by a quantitative analysis based on a combination of statistical methods and soft computing. Six indicators were selected for the analysis covering a period of 30 years (1990–2020).ResultsA significant obstacle to the green transition and the region’s transition to a circular economy and carbon neutrality is energy efficiency and energy related pollution—the reliance of most countries on coal-fired thermal power plants for electricity generation. The research results showed the following: (a) the degree of economic development and membership in the European Union are not significantly related to the level of energy efficiency; (b) most of the sampled countries are in the initial stages of introducing activities to achieve carbon neutrality; and (c) only Slovenia has documented consistent indicators and evident advancements in its efforts to achieve carbon neutrality. Based on the research findings, proposals for improvements were made in the direction of policymaking and in a methodological sense.ConclusionsThe implementation of circularity and carbon neutrality as a long-term goal of the European Union is not necessarily related to the level of economic development, nor can its trajectory be exclusively ascertained by means of data processing and monitoring. A more precise understanding of a carbon-neutral future can be achieved through the incorporation of qualitative data to a greater extent, a realistic evaluation of historical facts and their repercussions, as well as projections of the effects that reality and global developments after 2022 will have on each country.

Measurement of Environmental Gamma Radiation Dose Rates and Estimation of Radiation Risk near the Construction Site of the Nuclear Power Plant, Indoor and Outdoor Locations of the Research Reactor, and Coal-Fired Thermal Power Plant Area

Measurement of Environmental Gamma Radiation Dose Rates and Estimation of Radiation Risk near the Construction Site of the Nuclear Power Plant, Indoor and Outdoor Locations of the Research Reactor, and Coal-Fired Thermal Power Plant Area

Assessment and modeling of benzene micropollutant in surface waters proximal to coal-fired thermal power plants

ABSTRACT Micropollutants of priority have gained significant attention due to their rising concentrations and persistence in aquatic environments. Among these significant micro-pollutants is benzene, released into the environment because of mining activities, thermal power plants, and certain industrial operations, thereby contributing to environmental contamination. This study monitored benzene concentrations in the Orhaneli River over a year, employing an artificial neural network (ANN) approach to formulate a predictive model for benzene micropollutant concentrations. To provide input to the ANN, Principal Component Analysis (PCA) was employed, utilizing parameters such as precipitation, temperature, humidity, pH, flow rate, dissolved oxygen, conductivity, total organic carbon, and total nitrogen. Eleven backpropagation algorithms were compared, with the Levenberg-Marquardt algorithm identified as the optimal training algorithm. For the selected training algorithm, an optimized number of 6 neurons in the hidden layer provided the best predictions for benzene concentrations. The three-layered optimized ANN model achieved an impressive correlation coefficient (R2) of 0.9889.

Features of the Mechanism of Gas-phase Ignition of Wood Biomass Particles

ABSTRACT Use of woody biomass instead of coal as fuel for thermal power plants (TPP) is considered a promising direction for reducing emissions of anthropogenic substances during the operation of coal-fired thermal power plants. But the process of replacing coal with wood in the thermal power industry is happening very slowly due to objective reasons. The main one is the deposition of particles that have not fully passed the pyrolysis stage (in this case, a layer of substance in a resinous state is retained in the wood particle) on heating surfaces (for example, superheaters) and a decrease in the efficiency of using the heat of combustion of fuel as a result of contamination of the heating surfaces. Therefore, when developing technologies for burning dispersed wood in the furnaces of boiler units, reliable experimental data are required on the characteristic times of ignition and combustion of woody biomass particles, taking into account the time of transition from local (focal) gas-phase ignition to the combustion of volatiles in the entire vicinity of the particle (tsf). The article presents the results of experimental studies of flame propagation processes in the small vicinity of a particle during the ignition period. The experiments made it possible to establish that the flame propagation velocity in the small vicinity of the particle significantly depends on the ambient temperature. It is shown that under conditions of low-temperature heating (air temperature Tg = 873 K), the propagation velocity of the combustion (flame) is minimal. An increase in Tg values (from 873 K to 1273 K) leads to a significant (4–5 times) increase in the time of complete flame coverage of the particle. According to the results of the experiments, two heating modes were identified: high-temperature and low-temperature with a conditional interface Tg = 873 K. At Tg = 873 K, the characteristic particle size of wood biomass has no significant effect on the characteristics and conditions of flame propagation in a small vicinity of the particle. An increase in the ambient temperature (up to 1273 K) leads to an increase in the influence of particle size on the characteristics and conditions of flame propagation. A hypothesis describing the process of flame propagation has been developed.

Effect of Cr on the high-temperature corrosion of dissimilar AISI 904L and Inconel 625 joints employed in the coal-fired thermal power plant tubes

ABSTRACT The hot corrosion behaviours of 5-mm-thick plates of dissimilar AISI 904L and Inconel 625 weldments produced by continuous current gas tungsten arc welding process using Ni-Cr-Mo-enriched filler wires (ERNiCrMo-4 and ERNiCrCoMo-1) were investigated. Optical microscopy was used to examine the microstructure of these weldments. The corrosion performance of the weldments and base metals was determined in the mixture of K2SO4 + 60% NaCl molten salt (MS) and air oxidation conditions at 700°C for 50 cycles. The thermogravimetric plots derived the corrosion kinetics of the weldments. The microstructure and the elemental analysis of the scales formed on the corroded samples were evaluated by scanning electron microscopy and energy-dispersive spectroscopy. The phases developed on the oxide layers during the corrosion were analysed using X-ray diffraction. The fusion zones of ERNiCrCoMo-1 weldment and AISI 904L base metal were vulnerable to degradation in the MS environment, causing severe cracks and spallation compared to ERNiCrCoMo-1 weldment.

Journal Vol – 19 No -1, January 2024 Journal > Journal > Journal Vol – 19 No -1, January 2024 RELIABILITY OPTIMIZATION OF A DEGRADED SYSTEM UNDER PREVENTIVE MAINTENANCE USING GENETIC ALGORITHM Authors: Shakuntla Singla, Diksha Mangla, Poonam Panwar, S Z Taj DOI NO: https://doi.org/10.26782/jmcms.2024.01.00001 admin January 20, 2024 Abstract: The reliability parameters of a Mathematical model are analyzed for

The present paper deals with the lacunary interpolation problem called the mixed values problem or (0, 3; 0, 2) problem for which known data points are function values at all the points, third derivatives at even knots, and second derivatives at odd knots of the unit interval I = [0,1]. For this problem, we obtained an interpolating function. The paper is divided into two parts, where we have shown that the spline function exists and is convergent.

Monitoring For Elemental Composition Of Particulate Matter Deposited In Snow Cover Around Coal-Fired Thermal Power Plant (Karaganda, Central Kazakhstan).

Studies on thermal power plant areas with respect to chemical composition of particulate matter deposited in snow cover are limited. This study aims to monitor (2014–2022) particulate load and trace elements associated with the particulate matter distributed around (0.5-4.5 km) the coal-fired thermal power plant in Karaganda. In this study, snow cover was used as an effective scavenger of atmospheric pollutants. Using instrumental neutron activation analysis and atomic absorption spectrometry, the content of 26 elements and Hg, respectively, was determined in the particulate phase of snow. The results showed that particulate load varied from 26 to 1751, with mean of 427 and a background of 47 mg m-2 d-1. Anthropogenic impact caused a significant increase in content of U, Hg, Ta, Zn, Na, Cr, Co, Sr, Rb, Cs, Sc, Ca, Fe, Nd, Ba (2–30 times) in the samples compared to the background. Metal-bearing phases of Zn, Ba, As, U-Ta-Nb were detected through scanning electron microscope. The highest levels of particulate load (169–1032 mg m-2 d-1) and element contents in the samples were localized up to 0.7 km from the thermal power plant. The changes of particulate load and element composition of snow deposits during the monitoring period were connected with temperature, modernization of dust-collecting equipment, composition of coal and fly ash, long-range transport of emissions from other industries. The element content and metal-bearing phases in the particulate phase of snow can be used as markers for identifying emission sources from coal combustion.

Spatial Variability of Rare Earth Elements in Groundwater in the Vicinity of a Coal-Fired Power Plant and Associated Health Risk.

This study investigated the occurrence and distribution of rare earth elements (REEs), including 14 lanthanoids, scandium (Sc), and yttrium (Y), in groundwater around a large coal-fired thermal power plant (TPP). The ICP-MS technique was used to analyze 16 REEs in groundwater samples collected from monitoring wells. REE concentrations ranged from 59.9 to 758 ng/L, with an average of 290 ng/L. The most abundant was Sc, followed by La, accounting for 54.2% and 21.4% of the total REE concentration, respectively. Geospatial analysis revealed the REE enrichment at several hotspots near the TPP. The highest REE concentrations were observed near the TPP and ash landfill, decreasing with the distance from the plant and the landfill. REE fractionation ratios and anomalies suggested the Light REE dominance, comprising over 78% of the total REEs. Correlation and principal component analyses indicated similar behavior and sources for most REEs. Health risk assessment found hazard indices (HI) of 1.36 × 10-3 and 1.98 × 10-3 for adults and children, respectively, which are far below the permissible limit (HI = 1). Likewise, incremental lifetime cancer risks (ILCR) were all below 1 × 10-6. Nevertheless, ongoing ash disposal and potential accumulation in the environment could elevate the REE exposure over time.

Evaluation of radiological health risk caused by the use of fly ash in cement and concrete production and its storage

ABSTRACT As a result of firing pulverized coal in thermal power plants, enormous amounts of fly ash (FA) are produced as industrial waste. The release into the atmosphere and storage of this industrial waste remains one of the major environmental problems that threaten human health by contributing to air, water, and soil pollution. The recovery and reuse of FA in the construction industry is the only economic solution to the existing problem. In this study, the potential radiological risk caused by the usage of FA in concrete and cement production as a main component and its storage in landfill sites was evaluated for people and works by estimating radiological parameters (activity concentration and alpha index, annual effective doses, and the corresponding excess lifetime cancer risks) based on activity concentrations of terrestrial radionuclides in FA. Also, the radiological risk to the workers working in the FA landfill site was evaluated using the Residual Radioactivity Onsite 7.2 code. The average activity concentrations of terrestrial radionuclides in FA samples from the Tunçbilek lignite coal-fired thermal power plant at Kütahya province of Turkey were measured as 417, 156 and 454 Bq kg−1 for 226Ra, 232Th and 40K, respectively. When using up to 35% by mass of FA in cement and concrete, the average values of the radiological parameters revealed that they were within the recommended safety limits. However, code estimations showed that a regular worker in FA storage would be exposed to a total effective dose rate greater than 3 mSv y−1.

Energy footprint of the agriculture sector of Morocco

The agriculture sector is today the pillar of Moroccan economic growth as it provides around 38% of employment. Today following the modernization of Moroccan agriculture, the increase in energy demand has experienced a large flow of growth while almost all of the country’s energy, coming from fossil sources, is imported. Being one of the vital sectors for society, we analyzed its energy footprint from 2014 to 2021. The results showed that the energies used in the agricultural sector are electricity from coal-fired thermal power plants and diesel/ butane from petroleum. The change in the energy footprint was more than 29% for the study period. Crop production has the largest energy footprint with the cereal sector leading the way while poultry farms have the smallest footprint. The most serious environmental impact is observed at the level of farms using electricity produced from coal, while the cereal sector has more impact on resources. The practice of energy efficiency and the use of renewable energies prove led to a diminution of environmental impact and energy footprint of agriculture sector

Comparative Hygienic Assessment of the Composition of Ash and Dust Fractions in Ambient Air of the Area Affected by Emissions from a Thermal Power Station: Improving the Accuracy of Human Health Risk Assessment

Introduction: The relevance of the study is determined by a great number of functioning thermal power stations that operate using solid fuels (40 %) and are a source of ambient air pollution posing human health risks. Objective: A comparative hygienic assessment of the component, disperse, and morphological composition of fly ash and airborne particles in the area surrounding a coal-fired power station for the purpose of increasing the accuracy of human health risk assessment. Materials and methods: We have used unified and approved methods for hygienic assessment of ambient air quality; hazard identification and health risk assessment; scanning electron microscopy and micro-X-ray fluorescence spectroscopy of component, disperse, and morphological structure of fly ash and airborne particulate matter. Results and discussion: Large coal-fired thermal power plants emit about 36 chemicals. Over 59 % of brown coal ash particles are calcium, magnesium, iron, silicon, aluminum, sodium, potassium, sulfur, and phosphorus compounds. Particles found in fly ash and ambient air of the surrounding area have similar components and dispersion, are predominantly less than 10 µm in diameter with the sphericity index ranging from 0.4 to 1.0. Maximum allowable concentrations (MAC) of seven chemicals are exceeded in the study area: up to 3.3 single MAC, up to 1.4 average daily MAC, and up to 1.5 average annual MAC, with the estimated contribution of the thermal power stations of about 40 %. We have also established increased non-carcinogenic health risks with the dust fractions alone generating risk levels as high as 5.5 HQac, 2.4 HQch, and 6.9 HIch, which are rated as “high” and “alerting”. Identified solid particles (aluminum, magnesium, calcium, etc.) are more significant risk factors compared to unidentified particulate matter and can cause respiratory and circulatory diseases, diseases of the eye, etc., which requires their quantification. These chemicals are not included in air emissions inventory lists and are, therefore, not monitored. As a result, health risks posed by economic activities of thermal power stations may be underestimated.

Seismic Performance Assessment of a Cable-Damper Stopper Equipped for Coal-Fired Thermal Power Plants: Theoretical and Numerical Analyses

ABSTRACT A new cable-damper stopper equipped for Coal-Fired Thermal Power Plants (CFTPPs) was proposed in our previous paper, where a series of shaking table tests were carried out to investigate its seismic performance, so this paper aims to reveal the working mechanism of the stopper from the theoretical and numerical simulation aspects. The stopper is composed of three main components, i.e. a steel cable, a steel block and a viscous damper. First, the nonlinear restraint stiffness of the steel cable to the boiler was derived; second, the critical damping of the stopper, which makes the vibration of the boiler decay exponentially with no oscillation, was derived; third, an iterative method was proposed to globally tune the CFTPP structure, which makes it possible to obtain the optimal parameters of the cable-damper stopper, including the diameter of the steel cable and damping coefficient of the damper. Finally, finite element models were built and time history analyses were conducted to verify the proposed optimization approach. Firstly, the finite element models were proved valid through the comparison between the results of the simulations and the experiments. Then, based on the results of the simulations, the theoretical procedure was validated. The results revealed that the proposed cable-damper stopper reduced the seismic responses of displacements of the top floor and the boiler significantly, about 30.18% and 60.01% respectively compared with their counterparts of CFTPPs without stoppers.

Концептуальное проектирование базы данных углей на основе общих генетических признаков

The operational efficiency of coal-fired thermal power plants designed to utilize designed / standardized fuel and coking plants largely depends on the quality characteristics of the supplied coal products, the main indicators of which are: calorific value, ash content, moisture content, volatile matter yield, sulfur and nitrogen content, particle size distribution. Coal of various grades is mined in Russia, but not more than one third can be classified as the designed fuel. Accordingly, there arises a need to make fuel mixtures with specified parameters. The article justifies the topicality to create a database of qualitative characteristics and indicators of various coal grades. Using the results of analytical review of normative documentation, coal classification options have been developed based on the list of quality indicators specified in the state standard for identification of coals and coal products. Logical structure of the data, entity, relationships between them, attributes and constraints have been defined at the design stage of the database. The type and content of the conceptual model are presented as an ER-model visualized in the form of a graphical notation of the entity-vs-relationship diagram. Based on the analysis performed, ways of transaction and input data sources for the supplied coal characteristics and processing technologies have been defined. Examples of data structure in the models of individual entities and methods to determine their parameters have been provided.

A feature-state observer and suppression control for generation-side low-frequency oscillation of thermal power units

To construct a new energy system during the low-carbon transition, renewable energy sources (RESs) are increasingly being installed on a large scale worldwide which require thermal power units to operate at low loads and respond quickly to compensate for frequency fluctuations of the power grid during deep peak shaving and frequent load changes. While coal-fired thermal power plants operate under the deep-peak shaving process, low-frequency oscillation (LFO) accidents from the generation side have occurred constantly. According to our investigation, the reasons are the overlook of the nonlinearity of control valves is obviously highlighted under low load, and the preset parameters of the original control device can not match the flow characteristics, which may seriously cause a recurrence of LFOs. This paper focuses on generation-side LFO caused by the prime mover and its governor under all operating conditions constructing a novel nonlinear model and designing an oscillation feature observation matrix to identify the LFO modes, and a hierarchy feature-state observation classification method preventing LFO on the generation side is proposed. The results show that the proposed method can suppress the LFOs ahead, and this approach can weaken the oscillation amplitude by 85% and reduce the oscillation duration by 30 s.

Thermodynamic analysis of cycle arrangements of the coal-fired thermal power plants with carbon capture

Thermodynamic analysis of cycle arrangements of the coal-fired thermal power plants with carbon capture

AGC regulation capability prediction and optimization of coal-fired thermal power plants

The improvement of the AGC regulation capability of thermal power plants is very important for the secure and stable operation of the power grid, especially in the situation of large-scale renewable energy access to the power grid. In this study, the prediction and optimization for the AGC regulation capability of thermal power plants is proposed. Firstly, considering parameters related to the AGC regulation of the thermal power plant, the max-relevance and min-redundancy (mRMR) is used to extract features from historical sequences of the parameters. Next, a model with multi-long short-term neural networks (mLSTM) is constructed to predict the AGC regulation capability; that is, the obtained feature set is considered as the inputs of the first LSTM sub-model to predict future values of the main steam pressure and main steam temperature, which are then utilized as the inputs of the second LSTM sub-model to predict the actual power generation during AGC regulation operation. Then, the AGC regulation index is calculated according to the “management rules of grid-connected operation of power plant in Northern China” and “management rules of auxiliary service of the grid-connected power plant in Northern China” (i.e., “two rules”), and it is then considered as the objective function to be maximized by optimizing the coal feed rate, air supply rate, and feedwater flow rate. Finally, the actual AGC regulation process of a 300 MW coal-fired power plant is used as an application, and the results show that the proposed method can effectively predict and improve the regulation capability when the AGC instruction is received from the power grid.

Techno-economic Analysis of a Solid Fuel Testing Facility for Thermal Power Plants in Peninsular Malaysia: A Monte Carlo Approach

Coal-fired thermal power plants in Peninsular Malaysia are expected to remain operational for at least another 20 years, highlighting the need for clean coal technology adoption. The introduction of new coal types necessitates the verification of their technical viability prior to adoption into power plants, which is addressed by the proposed Solid Fuel Testing Facility (SFTF) system. Hence, this study developed a Monte Carlo-based model to examine the economic factors influencing the profitability of the SFTF system as a solid fuel pre-qualification assessment tool. Three critical factors have been identified as contributors to the SFTF system's economic viability uncertainty: the Test Number, Power Purchase Agreements (PPA) Reduction, and Test Cost. In terms of Net Present Value (NPV) valuation, the Test Number has the highest sensitivity. The projected increase in coal demand necessitating the inclusion of a broader spectrum of new coal variants in power plant operations. As a result, the possibility of an expanded Test Number for the SFTF system exists until the PPA's tenure expires. Therefore, the possibility of favourable NPV outcomes remains prominent throughout the term of the PPA. In contrast, the PPA Reduction has the lowest susceptibility to NPV sensitivity. This demonstrates the SFTF system's ability to navigate policy shifts related to PPA tenure reductions, albeit within a range of 3 to 4 years of reduction. It is suggested that a broader range of parameters be considered in order to gain a more holistic understanding of the economic viability of the proposed SFTF system.

Evaluation of potential radiological hazards of unfired construction materials containing fly ash in Vietnam.

In this study, the specific activities of 226Ra, 232Th and 40K in the unfired construction materials (solid card bricks, 4-hole bricks, pavement bricks) containing fly ashand bottom ash from a coal-fired thermal power plant in Vietnam were measured using the low-level gamma-ray spectrometer with HPGe detector. Also, the 222Rn concentrations in these materials were analyzed using RAD7 radon monitor and then radon mass exhalation rate and emanation fraction of these materials were calculated. The potential radiological hazards for residents living in the model room made of these materials were evaluated. The average specific activity of 226Ra, 232Th and 40K were found as 67.7, 79.3 and 703.5Bqkg-1, respectively. The total annual effective dose (due to external gamma exposure and internal radon exposure for resident living in the CEN model room made of the unfired brick samples) was found as 0.9mSvy-1 which is lower than the worldwide average dose of 2.4mSvy-1. Calculations from ResRad-Build code showed that the doses due to radon exposure account for from 62.3% (at the first year) to 98.8% (at the next 30years) of the total gamma and radon dose. Under low air exchange to the outside environment, from the 6th year onwards, the total dose may exceed the average dose value from natural radiation exposure sources.

Bi-decadal trend of atmospheric emissions from thermal power plants in Mainland Southeast Asia: Implications on acid deposition and climate change Mitigation

Steady increase in electricity generation and heavy reliance on coal in Mainland Southeast Asia (M-SEA) create huge pressure on the environment. This study used information collected from individual thermal power plants (TPPs) in M-SEA to calculate emissions of air pollutants and greenhouse gases (GHG) for 2010, 2015 and 2019. The emissions were projected to 2030 following the latest national Power Development Plans. The emission results were analyzed in relation to the power development by country and fuel type, and environmental impacts. The region collective annual TPP emissions in 2019, in Gg/yr, were 27 PM2.5, 77 PM10, 0.7 BC, 4.9 OC, 255 SO2, 451 NOx, 91 CO, 12 NMVOC, 0.4 NH3, 260 CO2, 13 CH4, and 26 N2O. Coal-fired TPPs dominated the emissions of most species while NG-fired contributed the largest amounts of NH3 and CH4. Bi-decadal increase in energy production from TPPs of nearly 3 times is accompanied by 2.7 times increase in emissions. The 2010–2019 period saw average emissions increase by 1.9 times (TPPs' energy production increased 1.6 times), slightly higher than the rate of 1.4 times projected for 2019–2030 (double TPPs’ energy production). The current intrusion rate of renewable energy accompanied by phasing-out of old TPPs are still by far insufficient to reverse the emission trend. Aggressive power development in Vietnam with its heavy coal reliance made it the largest emitter in 2019 and the projected for 2030, followed by Thailand. Spatially, higher emissions are seen over locations of large coal-fired TPPs in Vietnam and Thailand. Available rainwater composition monitoring data showed higher deposition amounts of sulfate and nitrate in areas located near or downwind of large TPPs. Significant GHG emissions projected for TPPs in 2030 indicated that TPPs should be the priority for emission reduction to achieve Nationally Determined Contribution targets. Emission database produced by this study can be used in dispersion modeling studies to assess impacts of TPPs on air quality, health, and acid deposition.

Assessing radioactivity and hazards: analysis of soil, water, and coal samples near a coal-fired thermal power plant and their implications for human health and the environment

ABSTRACT The combustion of coal poses significant risks, increasing the radioactive burden on the atmosphere and affecting the health of individuals near coal mines and coal-fired thermal power plants (CFTPPs). A detailed study was conducted within a 3 km radius surrounding the site of Barapukuria Coal Mine Company Limited (BCMCL), Bangladesh’s premier operational coal-fired thermal power plant, during which 50 soil samples, 50 water samples, and 21 coal samples were collected from a variety of locations inside and beyond the BCMCL boundaries, and these samples were then analysed for radioactivity using a high-purity germanium detector. The range of activity concentrations of 226Ra, 232Th, and 40K in the studied soil, water and coal samples were 24–47, 30–76, and 340–570 Bqkg−1; 1.6–2.9, 1.1–3.8, and 53–92 Bqkg−1; 19–57, 20–97, and 78–170 Bqkg−1 respectively. The majority of hazard indices, including absorbed dose rate, gamma index, effective dose, and excess lifetime cancer risk, associated with soil samples were higher than the world average. This indicates that long-term exposure to terrestrial ionising radiation is unsafe for coal miners and the local community. The quantitative measurements of this study have important implications for planning larger and more modern coal-fired power plants. Additionally, the study’s results underscore the need for municipal officials to impose restrictions and closely monitor the release of fly ash in the vicinity of coal-fired power plants. Furthermore, there is a crucial need to monitor the health of workers and locals living near the power plant to safeguard against potential health risks.