scholarly journals Numerical investigation using two different CFD codes of pulverized-coal combustion process characteristic in an industrial power plant boiler

2019 ◽  
Vol 82 ◽  
pp. 01009
Author(s):  
Paweł Madejski ◽  
Norbert Modliński
Keyword(s):  
Numerical Modeling ◽  
Coal Combustion ◽  
Power Plants ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Pulverized Coal ◽  
Front Wall ◽  
Coal Particles ◽  
Boiler Operation ◽  
Steam Boilers

Steam boilers using the coal as a basic fuel are still one of the most important techniques used to generate electricity in Power Plants. Many activities connected with optimization of steam boilers operation, investigation of combustion efficiency using different fuels, control and reducing pollutants emission are observed. Numerical modeling of large steam boilers using Computational Fluid Dynamic method can be a very way to develop and verify effects of all activities regarding combustion process optimization. Numerical modeling results of the coal combustion process in the front wall coal-fired boiler are presented in the paper. The behavior of the flow of pulverized coal through the burners was analyzed, and the temperature and velocity distribution in the combustion chamber were reproduced in the simulation. Despite the fact that the attention has been focused on boiler simulation at nominal load, it is possible to perform numerical studies concerning the analysis of coal combustion at different boiler loads (minimum load and flexible boiler operation). Analysis of different fuels and their impact on the combustion process, as well as analysis of coal mills operation, coal particles size distribution and they impact on boiler operation can be performed using developed models.

scholarly journals Transient Simulations of Spouted Fluidized Bed for Coal-Direct Chemical Looping Combustion

2014 ◽  
Author(s):  
Zheming Zhang ◽  
Ramesh Agarwal
Keyword(s):  
Carbon Capture ◽  
Power Plants ◽  
High Efficiency ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Successful Implementation ◽  
Chemical Looping ◽  
Two Phase ◽  
Coal Particles ◽  
Fuel Reactor

Chemical-looping combustion holds significant promise as one of the next generation combustion technology for high-efficiency low-cost carbon capture from fossil fuel power plants. For thorough understanding of the chemical-looping combustion process and its successful implementation in CLC based industrial scale power plants, the development of high-fidelity modeling and simulation tools becomes essential for analysis and evaluation of efficient and cost effective designs. In this paper, multiphase flow simulations of coal-direct chemical-looping combustion process are performed using ANSYS Fluent CFD code. The details of solid-gas two-phase hydrodynamics in the CLC process are investigated by employing the Lagrangian particle-tracking approach called the discrete element method (DEM) for the movement and interaction of solid coal particles moving inside the gaseous medium created due to the combustion of coal particles with an oxidizer. The CFD/DEM simulations show excellent agreement with the experimental results obtained in a laboratory scale fuel reactor in cold flow conditions. More importantly, simulations provide important insights for making changes in fuel reactor configuration design that have resulted in significantly enhanced performance.

Measurement & Control of Pulverized Coal Concentration in Exhaust Pneumatic Convey System

2012 ◽  
Vol 190-191 ◽  
pp. 1006-1009
Author(s):  
Xing Sen Yang ◽  
Jing Yin
Keyword(s):  
Power Plants ◽  
Fine Particles ◽  
Engineering Application ◽  
Pulverized Coal ◽  
Mixing Process ◽  
Horizontal Pipes ◽  
Controlling System ◽  
Coal Particles ◽  
Balance Analysis ◽  
Energy Balance Analysis

Pulverized coal firing boilers are widely used in power plants. Coal is pulverized into very fine particles and then mixed with primary air in horizontal pipes in the case of exhaust pneumatic convey system. The pulverized coal particles are conveyed by primary air to the burner and burn in the furnace. The concentration of pulverized coal in primary air should be well controlled to keep the safe and economic operation of the boiler. Credible measuring and controlling system is needed in engineering applications. Investigation of the mixing process shows that the pressure of primary air drops rapidly within the process, which gives the possible way to determine the pulverized coal concentration. The rapid pressure drop is mainly due to the acceleration of the pulverized coal particles. With energy balance analysis, study of the relationship between the mass flow rate of the pulverized coal and the pressure changes within the mixing process is done. The governing equation is achieved and the method of using two sections to measure the flow is proposed. The measuring and controlling system can be established according to the method. As a result, the measuring and controlling method provides a new way to meet the needs of engineering application.

scholarly journals Review of the investigations of pulverized coal combustion processes in large power plants in laboratory for thermal engineering and energy: Part A

2019 ◽  
Vol 23 (Suppl. 5) ◽  
pp. 1587-1609
Author(s):  
Branislav Repic ◽  
Predrag Stefanovic ◽  
Srdjan Belosevic ◽  
Nenad Crnomarkovic ◽  
Simeon Oka
Keyword(s):  
Coal Combustion ◽  
Power Plants ◽  
Technological Development ◽  
Pulverized Coal ◽  
Thermal Engineering ◽  
Pulverized Coal Combustion ◽  
Ministry Of Education ◽  
Large Power ◽  
Practical Applications ◽  
Scientific Meetings

The paper presents an overview of the results of the investigations of the processes that take place in pulverized coal combustion boilers and power plants which, in a longer period of time, were realized in the Laboratory for Thermal Engineering and Energy of the "Vinca" Institute of Nuclear Sciences. The presented results were published in numerous studies realized for different users, Ph. D., M. Sc., and specialist thesis, in international and domestic scientific journals and monographs, presented at numerous international and domestic scientific meetings, etc. The main goal of the paper is to chronologically present the results of domestic research that at one time were at an enviable international level, with concrete practical applications for domestic users. This is especially important to contrast the present situation when domestic research in this area is scarce and when the energy sector relies practically only on imported technologies and foreign consultancy. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III42011, Grant no. III42010, Grant no. TR33018 and Grant no. TR33042] <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/TSCI200127032E">10.2298/TSCI200127032E</a><u></b></font>

scholarly journals Review of the investigations of pulverized coal combustion processes in large power plants in laboratory for thermal engineering and energy: Part B

2019 ◽  
Vol 23 (Suppl. 5) ◽  
pp. 1611-1626
Author(s):  
Predrag Stefanovic ◽  
Dejan Cvetinovic ◽  
Zoran Markovic ◽  
Milic Eric ◽  
Simeon Oka ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Power Plants ◽  
Thermal Power ◽  
Pulverized Coal ◽  
Thermal Engineering ◽  
Thermal Power Plants ◽  
Pulverized Coal Combustion ◽  
Research Projects ◽  
Large Power ◽  
Combustion Processes

Paper presents short review of research problems, applied methods for solving problems and main results obtained by the researchers in Laboratory for Thermal Engineering and Energy (LTE) of the "Vinca" Institute of Nuclear Sciences, Belgrade, Serbia dealing with pulverized coal combustion processes and technologies for reduction of pollutions problems at thermal power plants in a period since 2000. The presented results were published in numerous studies realized for different users, Ph. D., Masters, and Specialist thesis, in international and domestic scientific journals and monographs, presented at numerous international and domestic scientific conferences, etc. Presented research projects and results of applied research projects realized at pulverized coal combustion thermal power plants clearly show that LTE team was involved in key activities of rehabilitation and modernization, including implementation of best available technologies for pollution reduction at thermal power plants, in the region of South East Europe.

scholarly journals Modeling of pulverized coal combustion for in-furnace NOx reduction and flame control

2017 ◽  
Vol 21 (suppl. 3) ◽  
pp. 597-615 ◽  
Author(s):  
Srdjan Belosevic ◽  
Ivan Tomanovic ◽  
Nenad Crnomarkovic ◽  
Aleksandar Milicevic
Keyword(s):  
Coal Combustion ◽  
Numerical Study ◽  
Nox Reduction ◽  
Combustion Process ◽  
Pulverized Coal ◽  
Operating Conditions ◽  
Nox Emission ◽  
Differential Model ◽  
No Formation ◽  
Turbulent Reactive Flows

A cost-effective reduction of NOx emission from utility boilers firing pulverized coal can be achieved by means of combustion modifications in the furnace. It is also essential to provide the pulverized coal diffusion flame control. Mathematical modeling is regularly used for analysis and optimization of complex turbulent reactive flows and mutually dependent processes in coal combustion furnaces. In the numerical study, predictions were performed by an in-house developed comprehensive three-dimensional differential model of flow, combustion and heat/mass transfer with submodel of the fuel- and thermal-NO formation/ destruction reactions. Influence of various operating conditions in the case-study utility boiler tangentially fired furnace, such as distribution of both the fuel and the combustion air over the burners and tiers, fuel-bound nitrogen content and grinding fineness of coal were investigated individually and in combination. Mechanisms of NO formation and depletion were found to be strongly affected by flow, temperature and gas mixture components concentration fields. Proper modifications of combustion process can provide more than 30% of the NOx emission abatement, approaching the corresponding emission limits, with simultaneous control of the flame geometry and position within the furnace. This kind of complex numerical experiments provides conditions for improvements of the power plant furnaces exploitation, with respect to high efficiency, operation flexibility and low emission.

scholarly journals Performance of Pulverized Coal Combustion under High Temperature Air Diluted by Steam

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mohsen Saffari Pour ◽  
Yang Weihong
Keyword(s):  
High Temperature ◽  
Coal Combustion ◽  
Fluid Dynamic ◽  
Flame Temperature ◽  
Experimental Tests ◽  
Injection Rate ◽  
Pulverized Coal ◽  
Injection Velocity ◽  
Pulverized Coal Combustion ◽  
Injection Speed

The high temperature air combustion (HiTAC) is an advanced promising technology for heat recovery, energy saving, and stability improvement of flame. Computational fluid dynamic (CFD) is known as an applied tool to execute HiTAC modeling. In this paper, performances of pulverized coal combustion under the high preheated and oxygen deficient air are studied by both experimental and numerical methodology. The experimental facilities have been accomplished in a HiTAC chamber with coal injection velocity that ranges from 10 to 40 m/s. In order to achieve different preheated temperatures, the combustion air in such system is diluted by variable steam percentages from 0 to 44%. Results of mathematical simulation and experimental tests present convincible agreement through whole region. It is concluded that NOX emission is reduced by increasing the steam percentage in the oxidizer due to decreasing the flame temperature. Besides, graphical contours show that by adding more steam to oxidizer composition, the oxygen concentration decreased. Additionally, results show that when the injection speed of fuel is increased, NOX emission is also increased, and when the injection rate of preheated air is increased, NOX emission shows decreasing trend. Further contribution in future is needed to investigate the performance of such technologies.

scholarly journals Coal combustion modelling in a frontal pulverized coal-fired boiler

2018 ◽  
Vol 46 ◽  
pp. 00010
Author(s):  
Paweł Madejski
Keyword(s):  
Coal Combustion ◽  
Gas Flow ◽  
Combustion Process ◽  
Three Dimensional ◽  
Pulverized Coal ◽  
Operational Conditions ◽  
Power Plant Boiler ◽  
Combustion Modelling ◽  
Flow Through ◽  
Plant Boiler

The paper presents results of numerical modelling of pulverized coal combustion process in the coal-fired boiler. In the numerical model, coal combustion process includes particle heating, devolatilization, char combustion, as well as turbulent flow and radiative heat transfer was modelled. Presented modelling results were carried out using the Open Source CFD code - Code_Saturne created and developed by EDF R&D and were used to study the combustion of coal in power plant boiler with the objective of simulating the operational conditions and identifying factors of inefficiency. The behaviour of the flow of air and pulverized coal through the burners was modelled, and the three-dimensional flue gas flow through the combustion chamber and heat exchangers was reproduced in the simulation.

Pressurised Oxy-Coal Combustion Rankine-Cycle for Future Zero Emission Power Plants: Technological Issues

2009 ◽  
Author(s):  
Marco Gazzino ◽  
Giovanni Riccio ◽  
Nicola Rossi ◽  
Giancarlo Benelli
Keyword(s):  
Coal Combustion ◽  
Carbon Capture ◽  
Power Plants ◽  
Process Integration ◽  
Scale Up ◽  
Combustion Process ◽  
Rankine Cycle ◽  
Intermediate Step ◽  
Combustion Technology ◽  
Zero Emission

Among possible options to capture carbon dioxide, pressurised oxy-fuel combustion is a promising one. Accordingly, Enel teamed with Itea and Enea to develop a pressurised oxy-combustion technology. Currently, extensive tests have been carried out at 4 bar on a 5 MWt facility based in Gioia del Colle (Southern Italy). By starting from the know-how gained on that scale, Enel planned to build by 2010 an experimental 48 MWt demo-plant, based on the same pressurised combustion process introduced above. This will be the necessary intermediate step for the further scale-up towards a zero emission plant of industrial scale. This paper is the prosecution of a previous publication presenting the process design and energy analysis of a power cycle integrating the developed pressurised oxy-coal combustion technology with a Rankine cycle including carbon capture. After having briefly presented the pressurised oxycombustion project carried out at Enel, the paper focuses on technology issues related to the proposed cycle and the related process integration, with respect to main components.

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