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Thermoelectric power plants can directly cause environmental impacts with respect to emissions of atmospheric gases caused by combustion for operation, being the main agents: unburned hydrocarbons, carbon oxides, sulfur oxides, nitrogen oxides, volatile organic compounds and material particulate. Thus, this research aimed to measure and compare the instantaneous levels of the chemical compounds CO2, CO, SO2, noise, air temperature, relative humidity, dew point temperature, wind speed and luminescence in two peri-urban areas of the surrounding a thermoelectric power plant in the interior of Paraíba, Brazil. To this end, data were collected using environmental sensors (a Garmin Gpsmap 62sc GPS camera 5mp; a Canon powershot SX60HS 16.1MP LCD 3.0 semi-professional digital camera, 65x optical zoom; an ITMCO2-600 meter for measuring CO2 and CO; one ITMP-600 multifunctional meter for AVG/MAX/MIN/DIF measurement, temperature measurement, humidity measurement, sound level measurement, luminescence measurement and wind speed measurement; and a GasAlert Extreme SO2 Gas detector to measure concentrations of sulfur in the environment), from October 2015 to March 2017, during daytime, between 7:00am to 9:00am, with weekly frequency, with instantaneous sampling measurements being collected at the collection points, near the thermoelectric power plant (Area 1) and close to the BR/104 highway (Area 2). The results showed that the records through the environmental sensors were not significant among the areas surveyed regarding the values of CO, CO2, SO2, air temperature, relative humidity, dew point temperature and luminescence. Regarding the wind speed, the two areas showed little variation. The noise levels in Area 1, on the other hand, during the operation of the thermoelectric power plant in its fullness, there was an increase above the permitted level, according to current Brazilian regulations, causing damage to the health of the inhabitants of its surroundings, in addition to harming the fauna of the surrounding area. around, mainly, the birds that are driven away by the noise, and, consequently, reducing the diversity of the avifauna surrounding the Thermoelectric. Thus, the use of environmental sensors to monitor the air quality of this area is very important, thus serving as a comparative support for future studies, as well as establishing the genesis for an environmental database in this metropolitan region of Campina Grande/PB, Brazil.

In this paper, the authors present a systematized methodology for modelling and analyzing the operating regimes of centrifugal pumps as working machines in electric drive systems. For solving, algorithms and calculation programs developed in the Mathcad programming environment were designed. For example, a representative case study was chosen of a condensing electric pump from the own services of a thermoelectric power plant with groups of 500 MW, driven by an induction motor with a squirrel cage rotor of 6 kV. It was thus possible to comparatively analyze two solutions for regulating the flow of a centrifugal pump in terms of energy efficiency.

Installing flue gas desulphurization systems before particulate collectors in thermoelectric plants generates spray dryer ash (SDA), a mixture of fly ash and sulfur products. SDA carries a ...

Maintenance optimization of multi-component systems is a difficult problem. Partially Observable Markov Decision Processes (POMDPs) are powerful tools for such problems under uncertainty in stochastic environments. In this study, the main POMDP solution approaches and solvers are surveyed. Then, based on experimental models with different complexities in the size of the system space, selected POMDP solvers using different representation patterns for modeling and different procedures for updating the value function while solving are compared. Furthermore, to show that factored representations are advantageous in modeling and solving the maintenance problem of multi-component systems where there exist also stochastic dependencies among the components, the maintenance problem of the one-line regenerative air heater system available in thermal power plants is modeled and solved with factored POMDPs. In-depth sensitivity analyses are performed on the obtained policy. The results show that factored POMDPs enable compact modeling, efficient policy generation and practical policy analysis for the tackled problem. Furthermore, they also motivate the use of factored POMDPs in the generation and analysis of maintenance policies for similar multi-component systems. This research is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under grant: 117M587. Publisher's Version WOS:000760341500011

Brazil presents the second largest coal reserves in Latin America, whose exploration is mainly focused on electricity generation. The present study was carried out to systematically evaluate the influence of various physical and chemical factors on the extraction of pure amorphous silica precipitated from coal-fired bottom ash. The coal bottom ashes (CBA) is a disposable waste from thermoelectric plants, which basically consists of oxides of silicon (80-60%), aluminium (25-20%) and iron (10-2%), being considered as raw material for silica production, by the sol-gel process. The CBA characterization was carried out by determining moisture, elemental composition (XRF), amorphism (XRD) and granulometry.The process evaluation tookplace in two stages: the quantitative evaluation that wasrelated to the quantification of the amount of silica obtained and the process variables (NaOH concentration and temperature); and the qualitative evaluationof the silica extracted. The extracted silica particles were characterized by TG, BET, XRD.Silica and aluminium contents were obtained by gravimetric analysis. Among the factors analysed, the concentration of sodium hydroxide and temperature interference were the most important. Likewise, the repeat process for the same ash sample (sequential extraction) proved to be more effective than increasing the NaOH concentration. The obtained yield was 51.34%. The silica is 89.4% pure, when 5,63% of impurities are related to aluminium oxide .

Survey data from the Energy Information Administration (EIA) was combined with data from the Environmental Protection Agency (EPA) to explore ways in which operations might impact water use intensity (both withdrawals and consumption) at thermoelectric power plants. Two disparities in cooling and power systems operations were identified that could impact water use intensity: (1) Idling Gap-where cooling systems continue to operate when their boilers and generators are completely idled; and (2) Cycling Gap-where cooling systems operate at full capacity, while their associated boiler and generator systems cycle over a range of loads. Analysis of the EIA and EPA data indicated that cooling systems operated on average 13% more than their corresponding power system (Idling Gap), while power systems operated on average 30% below full load when the boiler was reported as operating (Cycling Gap). Regression analysis was then performed to explore whether the degree of power plant idling/cycling could be related to the physical characteristics of the plant, its environment or time of year. While results suggested that individual power plants' operations were unique, weak trends consistently pointed to a plant's place on the dispatch curve as influencing patterns of cooling system, boiler, and generator operation. This insight better positions us to interpret reported power plant water use data as well as improve future water use projections.

A solar thermal power plant presents an environmentally friendly process for producing power. However, due to diurnal and seasonal variations in the availability of solar radiation, as well as unce...

In complex systems with stochastically dependent components which are not observed directly, determining an effective maintenance policy is a difficult task. In this paper, a dynamic Bayesian network based maintenance decision framework is proposed to evaluate proactive maintenance policies for such systems. Two preventive and one predictive maintenance strategies from a cost perspective are designed for multi-component dependable systems which aim to reduce maintenance cost while increasing system reliability at the same time. Tabu procedure is employed to avoid repetitive similar actions. The performances of the policies are compared with a reactive maintenance strategy and also with each other using different strategy parameters on a real life system confronted in thermal power plants for six different scenarios. The scenarios are designed considering different structures of system dependability and reactive cost. The results show that the threshold based maintenance which is the predictive strategy gives the minimum cost and maintenance number in almost all scenarios. This research is supported by the Scientific and Technological Research Council of Turkey (TUBITAK) under grant: 117M587. Publisher's Version

The power generation has been centralized for many years. The conventional power network comprises large hydropower plants (HPPs), thermoelectric power plants, and nuclear power plants. This chapter deals with the central generation and the most common power plants being used all over the world. It is aimed to provide further understanding of power generation and central generation plants in terms of their physical, mechanical, and electrical configurations. The HPPs have been represented according to architectural structures, hydraulic turbines, types of generators used for electromechanical conversion and power generation. Afterward, the thermoelectric plants have been discussed in terms of fuel types and operation principles that are the second major generation plants in many countries. The nuclear power plants that are being discussed and criticized for many years have also dealt in terms of their power generation structures and current situation in the world. The chapter is expected to provide a base before the representation of distributed generation and renewable energy sources in the following chapters.

Journal bearings play an important role on many rotating machines placed on industrial environments, especially in steam turbines of thermoelectric power plants. Babbitt damage (BD) and excessive clearance (C) are usual faults of steam turbine journal bearings. This paper is focused on achieving an effective identification of these faults through an intelligent recognition approach. The work was carried out through the processing of real data obtained from an industrial environment. In this work, a feature selection procedure was applied in order to choose the features more suitable to identify the faults. This feature selection procedure was performed through the computation of typical testors, which allows working with both quantitative and qualitative features. The classification tasks were carried out by using Nearest Neighbors, Voting Algorithm, Naive Associative Classifier and Assisted Classification for Imbalance Data techniques. Several performance measures were computed and used in order to assess the classification effectiveness. The achieved results (e.g., six performance measures were above 0.998) showed the convenience of applying pattern recognition techniques to the automatic identification of BD and C.

Submitted by Maria Aparecida (cidazen@gmail.com) on 2021-03-16T13:49:35Z No. of bitstreams: 1 GABRIEL ARAUJO_Dissertação.pdf: 2527855 bytes, checksum: 3afd2f560b46acc2a5b004134987de88 (MD5) Made available in DSpace on 2021-03-16T13:49:35Z (GMT). No. of bitstreams: 1 GABRIEL ARAUJO_Dissertação.pdf: 2527855 bytes, checksum: 3afd2f560b46acc2a5b004134987de88 (MD5) Previous issue date: 2020-07-31 The increase of non-dispatchable renewable sources supply in Brazilian electrical matrix is changing system's planning and operation complexity level. These sources main characteristics are the high variability and the difficulty of forecasting its generation. In this scenario, electrical system must respond properly to variations in generation from these sources. In other words, system must be flexible and, therefore, have mechanisms capable of compensating for this variability. Hydroelectric plants are main responsible for providing flexibility, however the difficulty of building new hydroelectric plants requires the installation of other technologies. Thus, this work evaluates and discuss characteristics of a flexible generators and concludes that Natural Gas Power Plants are among the most viable technically and economically to compensate for these variations and thus contribute to the energy security of the system. Therefore, this work evaluated some market mechanisms that can increase the supply of flexible resources, such as: bilateral contracts between non-dispatchable and flexible generators, ramping ancillary services, demand response, among others. Finally, assessed Maranhão State’s potential for receiving flexible resources. In Brazil, Maranhão is the 2nd largest natural gas producer onshore. Currently thermoelectric plants use all natural gas production to generate electricity and these plants already play an important role in system’s energy security. However, Maranhão may also use its large natural gas reserves to feed flexible generators and contribute to system’s flexibility in the face of increasing penetration of renewables. Maranhão has an excellent electrical energy transmission infrastructure and may receive liquified natural gas (LNG) terminals associated with thermoelectric power plants. Lastly, this work presents the main impacts of renewable sources penetration in Brazilian electrical matrix, some possible solutions and the role that Maranhão can play in this scenario. O aumento da oferta de fontes renováveis não-despacháveis na matriz elétrica brasileira está mudando o nível de complexidade do planejamento e da operação do sistema. Essas fontes têm como características principais a alta variabilidade e a dificuldade de previsão da geração. Nesse cenário o sistema elétrico local tem que responder adequadamente às variações na geração oriundas dessas fontes; ou seja, o sistema precisa ser flexível e, portanto, dispor de mecanismos capazes de compensar essa variabilidade. As hidrelétricas são as principais responsáveis por fornecerem flexibilidade, entretanto a dificuldade de construir novas hidrelétricas demanda a instalação de outras tecnologias. Desta forma, neste trabalho são avaliadas e discutidas as características que tornam um gerador flexível, concluindo-se que nesse cenário as termelétricas a Gás Natural (GN) aparecem como alternativa técnica e economicamente viável para compensar essas variações e contribuir com a segurança energética do sistema. Para tanto, avaliou-se alguns mecanismos de mercado que podem aumentar a oferta de recursos flexíveis, tais como: contratos bilaterais entre geradores nãodespacháveis e geradores flexíveis, oferta de serviços ancilares de rampa, resposta da demanda, dentre outros. Por fim, foi avaliado o potencial do Estado do Maranhão para instalação de recursos flexíveis. O Maranhão é segundo maior produtor de Gás Natural onshore no País. Atualmente toda sua produção é utilizada para geração de energia elétrica e as termelétricas existentes já desempenham um papel importante na segurança energética do sistema. Entretanto, o estado pode fazer uso de suas grandes reservas de Gás Natural como uma ferramenta para contribuir com a flexibilidade do sistema perante a crescente penetração de renováveis. Vale observar que o estado conta com excelente infraestrutura de transmissão de energia elétrica e existe a possibilidade de construção de terminais de GNL associados a termelétricas. Finalmente, são apresentados os principais impactos da penetração de fontes renováveis na matriz elétrica brasileira, algumas soluções possíveis e o papel que o Maranhão pode desempenhar nesse cenário.

Resumen Introducción: la demanda de energía eléctrica va de la mano del aumento de la población, por lo que para satisfacerla se debe asegurar la capacidad de generación eléctrica, esto incentivaría la construcción de plantas térmicas; aumentando los trabajadores expuestos a los peligros de termoeléctricas. Esta revisión tiene como fin identificar cuáles riesgos y peligros en termoeléctricas han sido estudiadas en el mundo durante el periodo 20072017. Objetivo: identificar, a través de una revisión bibliográfica, los principales peligros a que están expuestos los trabajadores de termoeléctricas. Materiales y métodos: se realizó una revisión sistemática teniendo en cuenta las recomendaciones de la guía PRISMA, se tuvieron en cuenta estudios acerca de los factores de riesgos a los que se exponen el personal de operaciones de centrales térmicas; para la búsqueda se establecieron dos algoritmos con descriptores DeCS y MeSH en las bases de datos Scopus, Pubmed, Scient Direct y Google académico, encontrándose 21 publicaciones que cumplían con los criterios de inclusión. Resultados: los peligros más relevantes para los trabajadores en termoeléctricas son físicos, ergonómicos, químicos, biológicos y psicosociales. Conclusión: los trabajadores de termoeléctricas están expuestos a varios peligros que pueden aumentar el riesgo de ocasionarles enfermedades respiratorias, musculoesqueleticas, pérdida de capacidad auditiva, cáncer, leucemia y su variedad, pericarditis, Alzheimer, Parkinson, daño genético y celular; también se pudo evidenciar que el efecto en la salud por exposición en campos magnéticos requiere de estudios de más profundidad. Abstract Introduction: the demand for electric power, goes hand in hand with the population increasing, to satisfy it, the power generation capacity must be ensured, this would encourage the construction of thermal plants; increasing the exposition of workers to the thermoelectric plant dangers. This review aims to identify which risks and dangers in thermoelectric plants have been studied in the world for the period 2007-2017. Objective: identify the main hazards to which thermoelectric workers are exposed through a literature review. Materials and methods: a systematic review was carried out taking into account the recommendations of the PRISMA guide, studies were taken into account about the risk factors to which thermal power plant operations personnel are exposed; Two algorithms with DeCS and MeSH descriptors were established in the Scopus, PubMed, Scient Direct and Google academic databases, with 21 publications meeting the inclusion criteria. Results: the most relevant hazards for thermoelectric workers are physical, ergonomic, chemical, biological and psychosocial. Conclusion: thermoelectric workers are exposed to various hazards that may increase the risk of respiratory, musculoskeletal, hearing loss, cancer, leukemia and its variety, pericarditis, Alzheimer’s, Parkinson’s, genetic and cellular damage; It could also be evidenced that the effect on health by exposure in magnetic fields requires more in-depth studies.

Under applied high pressure, the electronic, optical, structural, and other properties of narrow-bandgap telluride semiconductors are subjected to dramatic changes. They can include, for instance, structural and electronic topological transitions. In this work, we investigated the electronic properties of single crystals of three families of tellurides, namely, HgTe, PbTe, and Bi2Te3 by measurements of the thermoelectric power (the Seebeck coefficient) and electrical resistance under high pressure up to 10 GPa. The applied pressure led to spectacular variations in the electronic transport of all three tellurides. We addressed these effects to electronic topological transitions that could be driven by significant narrowing of the bandgaps in the normal-pressure phases of these compounds. In particular, at about 1 GPa, we observed an n-p switching in the conductivity of HgTe, which was well reproducible under multiple pressure cycling. In contrast, in PbTe, we found that an electronic topological transition irreversibly turns the conductivity from p- to n-type. An electronic topological Lifshitz transition in p-type Bi2Te3 crystals with a low carrier concentration enhanced the n-type conductivity in a narrow pressure region about 2-3 GPa and resulted in a double p-n-p conductivity inversion. An irreversible p-n conductivity switching in p-type Bi2Te3 happened already on decompression from a high-pressure phase from about 8 GPa. The stress-controlled p-n inversions of the electrical conductivity in these industrially important telluride materials can potentially find emergent applications in micro- and nanoelectronics. © 2020 Author(s). The research was supported by a grant of Ministry of Science and Higher Education of the Russian Federation No. 075-15-2020-797 (13.1902.21.0024).

The problems of tightening harmful emissions standards and meeting commitments to reduce greenhouse gas emissions require the development of environmentally and economically viable technologies to capture CO2 and its subsequent utilization. The integration characteristics of the generic technologies for CO2 emission utilization from energy industries with a short, medium- and long-term commercialization prospects are considered, depending on the level of technological maturity and market attractiveness. Potential CO2 consumers were classified according to the central most sensitive energy generation parameters: volumes, pressure, and purity, depending on the CO2 capture processes parameters and types of thermal power plants. The CO2 utilization unit principles designed for full CO2 capture by various industries under the Paris agreements are considered. The joint analysis of the operating and prospective power plants, leading industrial technologies based on CO2 consumption, has revealed three types of energy-industrial symbioses representing a cost-effective “Power Plant – CO2 Consumer” model. This model operates without CO2 capture and conditioning unit and has the efficiency close to the traditional power plant without emissions utilization. Critical technology solutions are being developed for one of these types.

The article presents some trends of multistage steam-driven ejectors improvement and examples of its implementation. Three relevant directions were picked out: increasing of reliability, profitability and efficiency. Regarding the reliability increasing, existing serial ejector designs of various manufactures were analyzed. A number of new technical solutions were designed. For profitability raising two approaches were considered: decreasing of primary steam parameters and effect of high ejector productivity to the vacuum deviation in the condenser. Efficiency increasing comprises jet devices improvement. For these reasons a design method was refined. In this case geometrical parameters of existing serial ejectors were summarized, CFD research was performed. The improved design method along with new design solutions are implemented in several ejectors successfully. New ejectors are set at thermal power plants and have shown a high technical-economical effect. © The Authors, published by EDP Sciences, 2020.

Обоснована возможность использования показателя относительной экономии топлива по сравнению с раздельной выработкой при решении задач, связанных с оптимизацией теплофикационных парогазовых установок (ТПГУ), в современных экономических условиях. Установлена взаимосвязь величины относительной экономии топлива по сравнению с раздельной выработкой для ТПГУ с внешними (системными) условиями, параметрами, структурой и режимом работы энергоустановки, а также интегральным экономическим эффектом. Установлено, что при заданном типе газотурбинной установки КПД цикла, удельная выработка электроэнергии на тепловом потреблении и относительная экономия топлива по сравнению с раздельной выработкой ТПГУ определяется параметрами утилизационного контура. Установлено, что коэффициент использования теплоты топлива ТПГУ, практически не зависит от начальных параметров пара. Установлено, что КПД цикла, удельная выработка на тепловом потреблении и относительная экономия топлива по сравнению с раздельной выработкой ТПГУ имеют ярко выраженный максимум, достигаемый при одном и том же значении начального давления пара. С помощью показателя относительной экономии топлива по сравнению с раздельной выработкой проведена оптимизация начального давления пара для ТПГУ (на базе ГТУ GT13E2) с паровым контуром одного уровня давления. Для данного типа ТПГУ оптимальное начальное давление составляет 5,5-6 МПа, в то время как для ПГУ-КЭС на базе аналогичной ГТУ оптимальное начальное давление пара составляет 3-3,5 МПа. Показано, что существенное влияние на относительную экономию топлива по сравнению с раздельной выработкой в ТПГУ оказывают внешние условия, отражаемые типом (эффективностью) замещаемой КЭС. Так относительная экономия топлива для рассматриваемой ТПГУ (на базе ГТУ GT13E2) по сравнению с ПГУ-КЭС на базе аналогичной ГТУ составляет 26-26,5%, а по сравнению с ПТУ-КЭС на базе серийного блока К-300-240 относительная экономия топлива увеличится до 37,9%., The paper justifies a possibility of using an indicator of relative fuel economy in comparison with separate generation of electric power and heat in solving problems related to optimization of combined heat and power combined-cycle gas plants (CHP CCGT) in modern economic conditions. We established the relationship between the value of relative fuel economy in comparison with the separate generation of electric power and heat for CCGT with external (system) conditions, parameters, structure and mode of operation of the power plant, as well as the integral economic effect. It was found that for a given type of gas turbine (GT), the efficiency of the cycle, the specific generation of electricity at thermal consumption and the relative fuel economy in comparison with the separate generation of electric power and heat for CCGT is determined by the parameters of the utilization circuit. It was found, that the coefficient of heat use of fuel of CCGT, practically does not depend on the initial parameters of steam. It was found, that the cycle efficiency, the specific generation of electricity at thermal consumption and relative fuel economy in comparison with the separate generation of electric power and heat for CCGT have a pronounced maximum, achieved at the same value of the initial steam pressure. The initial steam pressure was optimized for a CCGT (based on GT13E2) with a steam circuit of the same pressure level using the indicator of relative fuel economy compared to separate generation of electric power and heat. For this type of CCGT thermal power station, the optimal initial pressure is 5.5-6 MPa, while for a CCGT electric power station (based on GT13E2), the optimal initial steam pressure is 3-3.5 MPa. It was found that external conditions, reflected by the type (efficiency) of the replaced electric power station, have significant impact on the relative fuel economy in comparison with separate generation of electric power and heat for CCGT. The relative fuel economy in comparison with separate generation of electric power and heat for CCGT thermal power station (based on GT13E2) compared to the CCGT electric power station (based on GT13E2) is 26-26.5%, and compared to the steam power plant (based on the C-300-240 serial unit), the relative fuel economy will increase to 37.9%.

China’s rapid development in economy has intensified many problems. One of the most important issues is the problem of environmental pollution. In this paper, a new DEA approach is proposed to measure the environmental efficiency of thermoelectric power plants, considering undesirable outputs. First, we assume that the total amount of undesirable outputs of any particular type is limited and fixed to current levels. In contrast to previous studies, this study requires fixed-sum undesirable outputs. In addition, the common equilibrium efficient frontier is constructed by using different input/output multipliers (or weights) for each different decision making unit (DMU), while previous approaches which considered fixed-sum outputs assumed a common input/output multiplier for all DMUs. The proposed method is applied to measure the environmental efficiencies of 30 thermoelectric power plants in mainland China. Our empirical study shows that half of the plants perform well in terms of environmental efficiency.

It is considered that the Socialist Republic of Vietnam (Vietnam) has an ideal environment for introducing and spreading Smart Grids. Although power demands in Vietnam are increasing rapidly and continuously, the infrastructure for smart grids is still underdeveloped so that the demands have not been satisfied yet, and the same can be said for the other South-Eastern countries. Most of their thermoelectric power plants are generating power by using diesel generators and the hydroelectric power generation is another means of securing power. It seems that the governments in this region prefer a small-scale power system linked to new and renewable energies rather than supporting some large-scale power generation projects due to their regional characteristics being consisted of a number of islands where power infrastructures are inadequate. The demands for an independent power system are being demanded in the countries with many islands such as Indonesia, Malaysia or Thailand such that it is essential to find new export-oriented businesses in these areas and push ahead with the construction of test beds for smart grids. In this regard, this study considers the possibility of introducing a Korean model smart grid in Vietnam while considering their situation and trend of new and renewable energies.