scholarly journals Improving efficiency of thermal power plants through mine coal quality planning and control

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 721-733
Author(s):  
Mirjana Bankovic ◽  
Dejan Stevanovic ◽  
Milica Pesic ◽  
Aleksandra Tomasevic ◽  
Ljiljana Kolonja
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Calorific Value ◽  
Valuable Insight ◽  
Mining System ◽  
Coal Quality ◽  
Planning And Control ◽  
Control Units ◽  
Continuous Mining ◽  
And Control

The main goal of coal quality control in lignite mines is to supply coal to power plants within certain quality constraints. Coal properties can affect the efficiency, reliability, and availability of both the boiler and the emission control units. This paper presents a new based integrated mine process simulation approach to investigate the variability of the calorific value in exploitation a complex lignite deposits. Results provide valuable insight into the performance of a continuous mining system in terms of controlling coal quality variability.

scholarly journals Environmental Management Zoning of Coal-Fired Power Plants in China in the Context of Carbon Neutrality

2021 ◽  
Author(s):  
Wen Qiu ◽  
Mingxuan Zhao ◽  
Lianhong Lv ◽  
Hong Luo
Keyword(s):  
Environmental Management ◽  
Power Plants ◽  
Thermal Power ◽  
Quality Standard ◽  
Human Society ◽  
Environmental Capacity ◽  
Economic Activities ◽  
Carbon Neutrality ◽  
Control Units ◽  
And Control

The total amount of greenhouse gas emissions directly or indirectly generated by thermal power enterprises at any given time can be offset through afforestation, energy conservation and emission reduction. The present situation and control methods of CO2 emission in China's coal-fired thermal power industry are introduced. The complex ecosystem is a unity of ecological functions composed of human society, economic activities and natural conditions. In the context of carbon neutrality and based on the theory of composite ecosystem, this paper divides the coal-fired thermal power plants in China into environmental management zones, calculates the atmospheric environmental capacity, and puts forward the concept of regional atmospheric environmental capacity, classification and zoning control. Finally, the management and control units are classified, and differentiated management and control requirements are put forward to provide a reference for regional air quality standard planning.

The Analytical Research and Development of On-Line Monitoring Models of Thermal State for Turbine Rotor

2013 ◽  
Vol 744 ◽  
pp. 105-109
Author(s):  
Shi Liu ◽  
Heng Liang Zhang ◽  
Yan Zhou ◽  
Dan Mei Xie
Keyword(s):  
Power Plants ◽  
Thermal Stresses ◽  
Thermal State ◽  
Thermal Power ◽  
Turbine Rotor ◽  
Limiting Factors ◽  
Monitoring And Control ◽  
Start Up ◽  
Temperature Dependent Properties ◽  
And Control

Steam turbine units are required to start up and shut down as fast as possible to improve economy and load-response ability of the units under the qualification of safety. it is important to monitor and control thermal state in turbine during operation, especially during the process of start-up and shutdown. Thermal stresses in turbine rotor in thermal power plants are the limiting factors for rapid startup, shutdown or load change. In this paper the online calculation models of temperature and thermal stress for a two-dimensional axis-symmetric object are obtained after disposing of the nonlinear factor such as temperature-dependent properties by a transformation. The model gained can be used to analyze thermal states in thick-walled components, monitoring and control online.

scholarly journals Simulation and Control of Solar Thermal Power Plants

2010 ◽  
Vol 1 (08) ◽  
pp. 232-236 ◽  
Author(s):  
J. Gall ◽  
D. Abel ◽  
N. Ahlbrink ◽  
R. Pitz-Paal ◽  
J. Andersson ◽  
...  
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Solar Thermal ◽  
Thermal Power Plants ◽  
Solar Thermal Power ◽  
Simulation And Control ◽  
And Control

scholarly journals Design and Implementation of an Automatic Control for Two Axis Tracking System for Applications of Concentrated Solar Thermal Power

2018 ◽  
Vol 14 (4) ◽  
pp. 54-63
Author(s):  
Saad Tami Hamidi ◽  
Jamal Abdul-Kareem Mohammed ◽  
Laith Muhsin Reda
Keyword(s):  
Solar Radiation ◽  
Tracking System ◽  
Thermal Power ◽  
Minimum Cost ◽  
Experimental Tests ◽  
Design And Implementation ◽  
Control Units ◽  
Useful Heat Gain ◽  
Useful Heat ◽  
And Control

The present work presents design and implementation of an automated two-axis solar tracking system using local materials with minimum cost, light weight and reliable structure. The tracking system consists of two parts, mechanical units (fixed and moving parts) and control units (four LDR sensors and Arduino UNO microcontroller to control two DC servomotors). The tracking system was fitted and assembled together with a parabolic trough solar concentrator (PTSC) system to move it according to information come from the sensors so as to keep the PTSC always perpendicular to sun rays. The experimental tests have been done on the PTSC system to investigate its thermal performance in two cases, with tracking system (case 1) and without tracking system (case 2). The experimental results showed that the average solar radiation falling on the PTSC prototype in the two cases during the same time was 854 and 701 watt/m2, respectively, which means an increase in the solar radiation about 21.8 % when using tracking system. It was found that the average useful heat gain output of solar collector was equal to (376.2, 252.6 watt) for the two cases, respectively, so there was an increase of about 48.9 % when using the tracking system. Also, the average thermal efficiency of the PTSC was found to be (20.7, 26.5 %) for the two cases, respectively, which means an increase in the average efficiency by 28% with use of tracking system compared to the fixed case.

scholarly journals EMISSIONS OF GREENHOUSE GASES FROM UKRAINIAN THERMAL POWER PLANTS

2019 ◽  
pp. 3-12 ◽  
Author(s):  
I.A. Volchyn ◽  
L.S. Haponych
Keyword(s):  
Greenhouse Gases ◽  
Carbon Content ◽  
Co2 Emission ◽  
Power Plants ◽  
Thermal Power ◽  
Calorific Value ◽  
Unburned Carbon ◽  
Thermal Power Plants ◽  
Organic Fuels ◽  
Ch4 And N2o

In 2014, Ukraine signed and ratified the Agreement on associated with the EU. One of the requirements advanced in this Agreement lies in establishing the procedures of monitoring, reporting, and verification of the emissions of greenhouse gases (GG) from power plants. This system is based on the assemblage of procedures for estimating the GG emissions. Greenhouse gases formed at the combustion of organic fuels are CO2, CH4, and N2O. Carbon dioxide is the main GG emitted by power plants. In carrying out this work, we developed a method for the calculation of CO2 emission, formed during coal firing at thermal power plants (TPP), based on the carbon content factors with regard for the low calorific value of coal and heat loss due to unburned carbon. Using this method, we obtained the values of specific carbon content factors, CO2 emission factors and gross CO2 emissions from Ukrainian TPP during the last years. We also calculated the gross GG emissions. In 2018, the GG emissions at Ukrainian TPP were equal to 45.5 mln t of CO2-equivalent.The values of specific GG emissions per unit of supplied electric power constituted 1126 g/kW-h. This parameter reached 1186 g/kW-h for coal of grade A and L, and 1112 g/kW-h for grades G and DG. Ref. 16, Tab. 8.

scholarly journals Exergy efficiency analysis of lignite-fired steam generator

2018 ◽  
Vol 22 (5) ◽  
pp. 2087-2101
Author(s):  
Drenusha Krasniqi-Alidema ◽  
Risto Filkoski ◽  
Marigona Krasniqi
Keyword(s):  
Steam Generator ◽  
Flue Gas ◽  
Power Plants ◽  
Thermal Power ◽  
Calorific Value ◽  
Feed Water ◽  
Low Grade ◽  
Gas Temperature ◽  
Steam Generators ◽  
Energy And Exergy

The operation of steam generators and thermal power plants is commonly evaluated on a basis of energy analysis. However, the real useful energy loss cannot be completely justified only by the First law of thermodynamics, since it does not differentiate between the quality and amount of energy. The present work aims to give a contribution towards identification of the sources and magnitude of thermodynamic inefficiencies in utility steam generators. The work deals with a parallel analysis of the energy and exergy balances of a coal-fired steam generator that belongs to a 315 MWe power generation unit. The steam generator is de-signed for operation on low grade coal - lignite with net calorific value 6280 to 9211 kJ/kg, in a cycle at 545?C/177.4 bar, with feed water temperature 251?C, combustion air preheated to 272?C and outlet flue gas temperature 160?C. Since the largest exergy dissipation in the thermal power plant cycle occurs in the steam generator, energy, and exergy balances of the furnace and heat exchanging surfaces are established in order to identify the main sources of inefficiency. On a basis of the analysis, optimization of the combustion and heat transfer processes can be achieved through a set of measures, including retrofitting option of lignite pre-drying with flue gas and air preheating with dryer exhaust gases.

Chemical Intervention Combustion and Applications in Coal Saving and Reducing Emissions

2012 ◽  
Vol 512-515 ◽  
pp. 1106-1112
Author(s):  
Da Wei Hu ◽  
Yan Min Wang ◽  
Ai Zhi Yu
Keyword(s):  
Coal Combustion ◽  
Power Plants ◽  
Fossil Fuels ◽  
Greenhouse Gas Emission ◽  
Global Climate ◽  
Thermal Power ◽  
Combustion Process ◽  
Calorific Value ◽  
Combustion Method ◽  
Nonrenewable Resource

Coal as the world's most widely used fossil fuels, during the combustion process large amounts of greenhouse gas emission, which has a huge impact on global climate warming. However, coal is a nonrenewable resource, and the energy conservation is imperative. This paper, through analyzed the essential of coal combustion, and the feasibility and means for coal saving by using chemical intervention combustion. After tested the practical effects of chemical intervention coal combustion catalyst, which provided by Guangzhou Fenfang Environmental Protection Technology Co., Ltd. The results shown, the as received basis net calorific value at constant volume of the selected coal sample improved 8% which was tested by an oxygen bomb calorimeter, almost 1/6 sulfur was fixed in the cinder and the practical application coal saving effects in new dry rotary kilns and thermal power plants were more than 6%. Therefore, the chemical intervention combustion method has important significance in research and practical for coal saving and reducing emissions of pollutants.

scholarly journals Co-Combustion of Tire Pyrolysis Products and Wood Pellets

2021 ◽  
Vol 64 (4) ◽  
pp. 363-376
Author(s):  
A. V. Grytsenko ◽  
N. V. Vnykova ◽  
O. I. Pozdnyakova
Keyword(s):  
Sulfur Content ◽  
Power Plants ◽  
Thermal Power ◽  
Calorific Value ◽  
Volatile Matter ◽  
Ash Content ◽  
Wood Pellets ◽  
Combustion Heat ◽  
Large Power ◽  
Coal Slag

Thermal power plants remain one of the main sources of environmental pollution. The deterioration of the quality of traditional carbon-containing energy resources leads to the need to develop technologies for co-combustion of biofuel and coal at small and large power plants. The paper proposes the concept of using solid waste from tire recycling by adding to the composition of the mixed fuel “coal – wood waste” as a substitute for coal slag, which is formed during the utilization of worn-out tires by pyrolysis. The aim of the work was to determine the possibility of increasing the calorific value of wood pellets by co-firing with pyrolysis slag instead of coal without increasing the burden on the environment. At the same time, the following tasks have been set: to determine the lowest combustion heat of mixed fuels and assess its change when replacing coal with slag; to determine moisture content, total sulfur content, volatile matter yield, ash content of mixed fuels according to standard methods; to assess the change in these parameters when replacing coal with slag at the same component ratios; to determine the optimal ratios of components in mixed fuels, which will not increase the burden on the environment when replacing coal with pyrolysis slag. It has been determined that replacing coal with slag results in an increase in calorific value by 37–45 %, a decrease in ash content by 37–42 %, and an increase in the yield of volatile substances. At the same time, the sulfur content increases by 5.6–18 %. The use of traditional cleaning equipment is recommended in order to reduce the emission of sulfur dioxide. The research results make it possible to substantiate the possibility of replacing coal with slag in mixed fuels at certain ratios of components. A new direction of using solid products from recycling of rubber products, i.e. worn-out tires, has been proposed by the pyrolysis method in mixed fuels “slag-wood pellets” for small and medium-sized power plants.

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