scholarly journals THE ALGORITHM OF ANALYSIS OF ENERGY EFFICIENCY OF HEAT SUPPLY SOURCE

Author(s):  
В. Буланин ◽  
V. Bulanin

The main energy-consuming element of the heat supply system of cities and settlements is a source of heat energy. In connection with the need to minimize the cost of fuel and electricity for heat supply, the article presents an analysis of the energy balance of the steam turbine installation, on the basis of which new analytical expressions are developed that comprehensively characterize the efficiency of the power plant. In 2000 еру RD 153-34.1-09.163-00 "Model program of energy audits of thermal power plants and district boiler houses of joint-stock companies of power and electrification of Russia" was enacted. Some aspects of the analysis of the energy balance of the steam turbine installation using the relative increase in heat consumption for condensation power generation are considered. An analytical assessment of the impact of energy costs on the boiler unit's own needs on the energy balance of the thermal power plant is made.

Author(s):  
В. Буланин ◽  
V. Bulanin

The main sources of thermal energy for the heat supply of cities and settlements are fuel-based thermal power plants and boilers. The article provides an analysis of the energy balance of a power plant in connection with the need to minimize the cost of fuel and electricity for heat supply. New analytical expressions comprehensively characterizing the efficiency of a power plant are developed. The analytical assessment of the impact of energy costs for the boiler needs on the energy balance of thermal power plant is made; methods for constructing schemes of the energy balance of thermal power plant and assessment of fuel efficiency in the boiler are designed. Attention is paid to errors arising from the use of the calculated values of air suction in the gas path of the boiler, and not the actual ones. Therefore, it is proposed to change the method of measuring heat loss with flue gases in order to eliminate or reduce the effect of air suction on the measurement results, taking into account the part of the flue gas heat received by the air in the air heater and returned to the boiler through the burner. The methods increasing accuracy of calculations of energy efficiency of the technological processes which are key in the centralized heat supply of the cities and settlements are developed.


2006 ◽  
Vol 20 (25n27) ◽  
pp. 4371-4376
Author(s):  
SUNGHO CHANG ◽  
GEEWOOK SONG ◽  
BUMSHIN KIM ◽  
JUNGSEB HYUN ◽  
JEONGSOO HA

The operational mode of thermal power plants has been changed from base load to duty cycle. From the changeover, fossil power plants cannot avoid frequent thermal transient states, for example, start up and stop, which results in thermal fatigue damage at the heavy section components. The rotor is the highest capital cost component in a steam turbine and requires long outage for replacing with a new one. For an optimized power plant operational life, inspection management of the rotor is necessary. It is known in general that the start-up and shutdown operations greatly affect the steam turbine life. The start-up operational condition is especially severe because of the rapid temperature and rotational speed increase, which causes damage and reduction of life of the main components life of the steam turbine. The start-up stress of a rotor which is directly related to life is composed of thermal and rotational stresses. The thermal stress is due to the variation of steam flow temperature and rotational stress is due to the rotational speed of the turbine. In this paper, the analysis method for the start-up stress of a rotor is proposed, which considers simultaneously temperature and rotational speed transition, and includes a case study regarding a 500MW fossil power plant steam turbine rotor. Also, the method of quantitative damage estimation for fatigue-creep damage to operational conditions, is described. The method can be applied to find weak points for fatigue-creep damage. Using the method, total life consumption can be obtained, and can be also be used for determining future operational modes and life extension of old fossil power units.


2019 ◽  
Vol 1 (20) ◽  
Author(s):  
Vesna Tunguz ◽  
Bojana Petrović ◽  
Zoranka Malešević ◽  
Slađana Petronić

Soil is one of the most important natural resources. Measurement of natural radioactivity in soil is very important to determine the amount of change of the natural background activity with time as a result of any radioactivity release. Coal mine and thermal power plant in Gacko field is a very important industrial facility. The content of radionuclides of the soil was examined at Gacko area, slag, ash and mullock dumps in thethermal power plant Gacko and soils of dumps in the process of re-cultivation. The gamma – spectrometric measurements were done in the Institute of Nuclear Sciences “Vinča” in Belgrade.Soil samples were collected in 2010/2014 at more locations in eastern part of Republic of Srpska. After removing the stones and vegetation, all soil samples for Gama spectrometric measurements dried up to 0 105 C, sieved, placed in the plastic 500 mL Marinelli beakers and left for four weeks to reach radioactive equilibrium. Given that there are no specific regulations in the Republic of Srpska, the concentration of natural and produced radionuclides in samples from the working and living environment of thermal power plants, comparison with literature data from the region and the world is one way of evaluating the impact of the plant's operation on the soils. The results point to the necessity of regular monitoring of radioactivity in eastern Herzegovina in order to assess the impact of the technologically increased natural radioactivity.


Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
Joa˜o Roberto Barbosa ◽  
Luiz Augusto Horta Nogueira ◽  
Electo E. Silva Lora

The operational rules for the electricity markets in Latin America are changing at the same time that the electricity power plants are being subjected to stronger environmental restrictions, fierce competition and free market rules. This is forcing the conventional power plants owners to evaluate the operation of their power plants. Those thermal power plants were built between the 1960’s and the 1990’s. They are old and inefficient, therefore generating expensive electricity and polluting the environment. This study presents the repowering of thermal power plants based on the analysis of three basic concepts: the thermal configuration of the different technological solutions, the costs of the generated electricity and the environmental impact produced by the decrease of the pollutants generated during the electricity production. The case study for the present paper is an Ecuadorian 73 MWe power output steam power plant erected at the end of the 1970’s and has been operating continuously for over 30 years. Six repowering options are studied, focusing the increase of the installed capacity and thermal efficiency on the baseline case. Numerical simulations the seven thermal power plants are evaluated as follows: A. Modified Rankine cycle (73 MWe) with superheating and regeneration, one conventional boiler burning fuel oil and one old steam turbine. B. Fully-fired combined cycle (240 MWe) with two gas turbines burning natural gas, one recuperative boiler and one old steam turbine. C. Fully-fired combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. D. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. The gas turbine has water injection in the combustion chamber. E. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners and one old steam turbine. The gas turbine has steam injection in the combustion chamber. F. Hybrid combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners, one old steam boiler burning natural gas and one old steam turbine. G. Hybrid combined cycle (235 MWe) with one gas turbine burning diesel fuel, one recuperative boiler with supplementary burners, one old steam boiler burning fuel oil and one old steam turbine. All the repowering models show higher efficiency when compared with the Rankine cycle [2, 5]. The thermal cycle efficiency is improved from 28% to 50%. The generated electricity costs are reduced to about 50% when the old power plant is converted to a combined cycle one. When a Rankine cycle power plant burning fuel oil is modified to combined cycle burning natural gas, the CO2 specific emissions by kWh are reduced by about 40%. It is concluded that upgrading older thermal power plants is often a cost-effective method for increasing the power output, improving efficiency and reducing emissions [2, 7].


2012 ◽  
Vol 608-609 ◽  
pp. 1298-1301
Author(s):  
Yong Li ◽  
Shi Ming Xu ◽  
Sheng Wen Huang ◽  
Wu Yi Du

Based on the situation that the transformations of the technology which is used to reclaim the physical sensible heat of the boiler slag in some industrial captive power plants, it has been used the heat balance method and the equivalent heat drop method to calculate and analyze the thermal economic indicators before and after the transformations of the unit, and then reveal the mechanism of the impact of the boiler slag’s physical sensible heat on the thermal economy of the whole plant.


Author(s):  
Sergio M. Camporeale ◽  
Bernardo Fortunato ◽  
Alessandro Saponaro

Repowering of an existing steam power plant by means of solar concentrating collectors is examined as a viable option to decrease CO2 emissions and increase electric power production during daytime peak load energy demanding hours. In the proposed scheme, the regenerative bleeds from the steam turbine are partially intercepted while boiler feed-water is heated by means of parabolic solar trough concentrating collectors. It is considered that fossil boiler, steam turbine and condenser are the same of the original plant, without modifications. After choosing a steam cycle reproducing an existing power plant, the scheme of solar repowering is examined and the efficiency of conversion of the solar energy is optimized in relation to the characteristics of the solar collector. The paper shows that the modified scheme produces very little effects on the working conditions of the existing components, either at full load or partial load, and does not reduce the conversion efficiency of the fossil fuel. In comparison with solar thermal power plants with heat storage and only solar energy as thermal input, the proposed scheme is expected to have comparable efficiency but lower costs per kWh produced, as a consequence of the fact that there is no need for steam turbine, condenser, cooling tower and auxiliary boiler. Moreover it is expected that personnel and maintenance costs will be lower.


Author(s):  
Cássio Florisbal de Almeida ◽  
Vinícius Gonçalves Maciel ◽  
Luiz Fernando de Abreu Cybis

O setor energético é de suma importância para o crescimento estratégico de qualquer país. Isso não é diferente no Brasil, o qual apresenta uma matriz energética diversificada, mas que tem um predomínio do setor hidrelétrico. No entanto, o setor termelétrico tem crescido nos últimos anos para garantir a segurança energética e, nos sistemas isolados, a termeletricidade é predominante. Este é o caso do estado do Amazonas, o qual recebe energia prioritariamente de usinas termelétricas da região. As usinas da região utilizam, em sua maioria, combustíveis fósseis tais como diesel, óleo combustível pesado (HFO, em inglês). Atualmente, tem sido incorporada a este sistema a utilização do gás natural proveniente da bacia petrolífera amazônica, localizada em Urucu. Nesse sentido, para analisar a influência ambiental desta mudança nas usinas termelétricas, este emprega a metodologia de Avaliação do Ciclo de Vida (ACV) da eletricidade entregue ao grid por uma usina termelétrica, localizada em Manaus, que utiliza óleo combustível pesado e gás natural como combustível. O estudo foi conduzido do berço ao portão da usina a partir de dados primários da própria usina e dados secundários de bibliografia da área. Para a observação das diferenças, fez-se um estudo comparativo entre a mesma usina em duas situações: utilizando somente óleo combustível pesado e o uso concomitante deste combustível com o gás natural. A Avaliação do Impacto de Ciclo de Vida foi calculada pelo método CML IA baseline com o uso do software SimaPro e escolheu-se a categoria de impacto de Aquecimento Global para análise. A conversão bicombustível resultou em redução do impacto da usina, que antes era de 590,50 kg CO2eq/MWh e passou para 521,11 CO2eq/MWh, no entanto ao longo do ciclo de vida o resultado se manteve no mesmo patamar. Resumen El sector energético es de suma importancia para el crecimiento estratégico de cualquier país. Esto no es diferente en Brasil, que tiene una matriz energética diversificada, pero que tiene un predominio del sector hidroeléctrico. Sin embargo, el sector termoeléctrico ha crecido en los últimos años para garantizar la seguridad energética y, en sistemas aislados, termoelectricidad es predominante. Este es el caso de estado del Amazonas, que recibe energía principalmente de centrales térmicas de energía en la región. Las plantas de la región utilizan, sobre todo, combustibles fósiles como el diesel, fuelóleo pesado (HFO en inglés). En la actualidad, se ha incorporado a este sistema, el uso de gas natural de la cuenca petrolífera del Amazonas, situado en Urucu. En este sentido, para analizar el impacto ambiental de este cambio en las centrales térmicas, este estudio emplea la metodología del Análisis de Ciclo de Vida (ACV) de la electricidad entregada a la red por una central térmica, que se encuentra en Manaus, que utiliza fuelóleo pesado y gas natural como combustibles. El estudio se realizó a partir de datos primarios de la central térmica y datos secundarios de literatura del área. Para observar las diferencias, se hizo un estudio comparativo de la misma planta en dos situaciones: utilizando sólo el fuelóleo pesado y el uso concomitante de este combustible con gas natural. La evaluación del impacto del ciclo de vida se calculó por el método de CML IA baseline usando el software SimaPro y optó por categoría de impacto del calentamiento global para análisis. La conversión bi-combustible resultó en una redución del impacto de la planta, que antes era de 590.50 kg CO2eq / MWh y aumentó a 521.11 CO2eq / MWh. Sin embargo a lo largo del ciclo de vida, el resultado se mantuvo en el mismo nivel. Abstract The electric sector is very important to the strategic growing of any country. It isn’t different in Brazil, which shows a diversified energy matrix, but has a predominance of hydropower sector. However, the thermoelectric sector has grown in the last years to guarantee the electrical safety and, in isolated systems, the thermoelectricity is predominant. It is the case of Amazonas State, which receives energy priority from thermal power plants in the region. They use, mostly, fossil fuels such as Diesel, Heavy Fuel Oil (HFO). Nowadays, it has been incorporated into this system the natural gas use from Amazon oil basin, located in Urucu. In this sense, to analyze the environmental influence of this change on the thermal power plants, this study intends to employ the methodology of Life Cycle Assessment (LCA) of the electricity delivered to the grid by one thermal power plant (TPP), located in Manaus, which uses HFO and Natural Gas as fuel. For observation of differences, it was performed a comparative study of this power plant in two situations: using only HFO and using HFO and Natural gas concomitant. The study was conducted from cradle to gate of the power plant from specific primary data, provided by the power plant and secondary data from the literature. The Life Cycle Impact Assessment (LCIA) was calculated from the CML IA baseline with the use of SimaPro software and it was chosen the impact category of Global Warming Potential (GWP) for analysis. The conversion bifuel resulted in reduction of the impact of the TPP, which previously was 590.50 kg CO2eq / MWh and passed to 521.11 CO2eq / MWh. However, the bifuel power plant has, along the lifecycle, when compared the operation with only HFO, the same magnitude of GWP due to contributions of, for example, natural gas production.


The global warming is a major thread in recent days. Industrial pollution is a prime contributor to global warming especially pollution due to coal fired power plants. In global electrical power scenario, maximum portion of required electrical energy is produced from coal fired thermal power plants. Steam turbine is major equipment in it, which converts heat energy in to mechanical energy. The energy conversion efficiency is most important one. Reduction in efficiency means wastage or loss of energy and leads to increase the cost of generation. Here, case study is conducted in the topmost coal fired thermal power plant in south India. The objective of the study is to recognize and evaluate the most influential drivers in the coal fired thermal power plant. If the most important drivers which highly influencing steam turbine efficiency are identified. In this paper, to recognize the most influential drivers for affecting steam turbine efficiency by using DEMATEL technique. The outcomes of the paper expose that steam pressure (D1) is the most influential driver in the coal fired thermal power plant and they need more focus to control it


2016 ◽  
Vol 2 (01) ◽  
Author(s):  
Namita Gupta ◽  
S. K. Dwivedi ◽  
D. Upreti

Coal based thermal power plants are considered as major point sources emitting considerable amount of particulate matter, fly ash, greenhouse gases, non-combustible hydrocarbons and metals. In order to assess the impact of thermal power plant in Eastern Uttar Pradesh, India, two morphologically distinct lichen species Pyxine cocoes and Bacidia incongruens have been used for conducting biomonitoring studies around thermal power plant located in Tanda district (Uttar Pradesh). Result shows that both the species differs in morphology and anatomy but bioaccumulates more or less similar concentration of metal through adsorption and absorption, as validated by SEM and FTIR respectively. The bioaccumulation in particulate form absorbed on the surface of the lichen thallus further support the particulate bound association of the pollutants emitted from thermal power plant a source of metals. .


2021 ◽  
Vol 2096 (1) ◽  
pp. 012150
Author(s):  
E Burdenkova

Abstract This work is devoted to the problem of utilization of waste heat from condensers of thermal power plants and nuclear power plants. The waste heat of the condensers of TPPs and NPPs, together with the circulating water, enters the environment, causing its thermal pollution. The use of this heat in an energy-biological complex, for example, in fisheries, increases their efficiency and solves an environmental problem. Compared to ordinary ponds, this energy complex has an almost year-round increase in biomass and accelerated maturation of producers. The article presents a developed methodology that makes it possible to assess the effectiveness of such a fishery. Calculations using this method were carried out for a fish farm raising sturgeons on the basis of the waste heat of a nuclear power plant with a VVER-1200 reactor and a K-1200-6.8/50 turbine


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