scholarly journals Verification of three-dimensional mathematical modeling when calculating the combustion of hydrocarbon fuel in an experimental cylindrical furnace enriched with a plasma fuel system

2020 ◽  
Vol 4 (315) ◽  
pp. 96-105
Author(s):  
V. E. Messerle ◽  
◽  
S. A. Bolegenova ◽  
M. K. Bodykbayeva ◽  
A. A. Kuykabayeva ◽  
...  
Keyword(s):  
Coal Combustion ◽  
Thermal Power ◽  
Combustion Process ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Hydrocarbon Fuel ◽  
Fuel System ◽  
Two Phase ◽  
Coal Particles ◽  
Kinetics Of

In this work, the operation of the boiler in traditional and plasma-activated conditions is investigated. To test the possibility of modeling the Cinar ICE program with an understanding of the physical mechanism of the processes of electrothermochemical fuel preparation (ETCF) and combustion, a study of coal combustion in an experimental furnace with a thermal power of 3 MW equipped with a plasma fuel system was carried out. To study the combustion process of an air mixture that had undergone preliminary plasma preparation for combustion, one-dimensional plasma-coal and three-dimensional computer programs Cinar ICE were used, which study in detail the mechanism of the kinetics of thermochemical exchange in a two-phase flow, where the plasma fuel source is located, and the exact geometry of the furnace, and the kinetics of the process сombustion of coal particles. As a result of calculations, the distribution of temperature, velocity of gas and particles in the process of ETCPT, the concentration of gas-phase mixtures, the concentration of carbon and the degree of gas contamination in the remainder of alloyed coal were determined. It was found that the plasma activation of combustion affects the thermal characteristics of the Torch, the mechanical non-combustible fuel residue and the concentration of nitrogen oxide at the outlet from the furnace. It has been proven that when simulating coal combustion, it is possible to achieve an effective description of the process using the Cinar ICE program.

Investigation on the Evolution of the Coal Macromolecule in the Process of Combustion With the Molecular Dynamics Method

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Bonan Xu ◽  
Hanhui Jin ◽  
Hanqing Li ◽  
Yu Guo ◽  
Jianren Fan
Keyword(s):  
Molecular Dynamics ◽  
Chemical Reactions ◽  
Coal Combustion ◽  
Ring Opening ◽  
Combustion Process ◽  
Three Dimensional ◽  
Structural Evolution ◽  
Coal Particles ◽  
Dynamics Method ◽  
Detailed Chemical

Abstract It is reported that a three-dimensional cross-linked macromolecular structure with heterogeneous inorganic and organic compositions widely exists in coal particles. The macromolecules usually represent the rank transition of more than 75% of the carbon (C) content of coal particles. In order to know the coal combustion process better, it is important to specifically study the evolution of the coal macromolecule during combustion. In this paper, the structural evolution and the detailed oxidization reactions of a coal macromolecule during the process of combustion are numerically studied with the reactive force field (ReaxFF) molecular dynamics (MD) method, in which the carbon (C) and hydrogen (H) atoms are fully oxidized to CO2 and H2O, respectively. It is found that the coal macromolecule experiences three main stages sequentially: the cleavage, the ring opening, and the oxidation. The heteroatoms (O, N, and S) inside the coal macromolecule are found to play important roles throughout the whole combustion process. The detailed chemical reactions with their occurrence frequencies show that the chemical reactions with O2 mainly occur in C1–4 fragments, and the C1–2–H–O fragments widely exist in the system before they are finally oxidized to CO or CO2.

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.

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.

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.

A Three-Dimensional Air-Vapor-Droplet Local Interaction Model for Spray Units

1981 ◽  
Vol 103 (3) ◽  
pp. 514-521 ◽  
Author(s):  
S. J. Palaszewski ◽  
L. M. Jiji ◽  
S. Weinbaum
Keyword(s):  
Numerical Model ◽  
Flow Field ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Interaction Model ◽  
Absolute Humidity ◽  
Local Variation ◽  
Computer Time ◽  
Two Phase ◽  
Time Model

An approximate fully three-dimensional numerical model for predicting the detailed flow and thermal characteristics of spray units is presented. The new model differs from all previous analyses of spray cooling systems in that it determines the local variation in the dry-bulb temperature, absolute humidity and the air streamlines throughout the flow field encompassing the spray umbrella and the effect of this local variation on drop cooling. The conservation equations to determine the local absolute humidity, velocity and dry-bulb temperature of the air-vapor phase are written in Lagrangian form where the droplets are treated as spatially varying sources of mass, momentum and energy. The analysis takes into consideration stable and unstable meteorological conditions, turbulent mixing in the atmospheric surface layer and nonuniform upwind and local air-velocity profiles. The numerical model is of intrinsic interest because it demonstrates the feasibility of computing a three-dimensional, two-phase flow field without the use of excessive computer time. Model predictions of droplet return temperature along the spray centerline were compared with data for the Spraco 1751 nozzle. Good agreement was observed.

scholarly journals Mass Loss of Coal Particles Burning in Fluidized Bed

2017 ◽  
Vol 62 (2) ◽  
pp. 339-354 ◽  
Author(s):  
Piotr Pełka
Keyword(s):  
Mass Loss ◽  
Combustion Process ◽  
Oxygen Deficit ◽  
Inert Material ◽  
Fuel Particle ◽  
Erosion Process ◽  
Two Phase ◽  
Whole Process ◽  
Coal Particles ◽  
Fuel Particles

AbstractIn this work many conclusions resulting from research carried out on the coal combustion process of the chosen coal type and its accompanying erosion in a two-phase flow of inert material have been presented. The purpose of this flow was to present a model of the conditions of the central and upper zone of the combustion chamber of the fluidized boiler. In the opinion of many authors (Basu, 1999; Chirone et al., 1991), the erosion process results from the contact of a fuel particle with particles of inert material that is responsible for generating fine fuel particles of less than 100 mm. If the particles are in the upper zone of the boiler where there is oxygen deficit, they can increase the loss of incomplete combustion substantially. The results of research do not confirm this common thesis, but rather indicate that the process of comminution that results from erosion under oxidative conditions contributes to the increase of substantial mass loss of a coal particle, however the increased mass loss of particle during combustion is first and foremost due to the whole process of removal of ash from the reactionary surface of a fuel particle. Nevertheless, in the conditions of oxygen deficit the comminution of particles as a result of the erosion process is negligible

scholarly journals The use of mechanically activated micronized coal in thermal power engineering

2016 ◽  
Vol 20 (suppl. 1) ◽  
pp. 23-33 ◽  
Author(s):  
Anatoliy Burdukov ◽  
Evgeniy Butakov ◽  
Vitaliy Popov ◽  
Mikhail Chernetskiy ◽  
Nelya Chernetskaya
Keyword(s):  
Coal Combustion ◽  
New Technology ◽  
Thermal Power ◽  
Combustion Process ◽  
Power Engineering ◽  
Fuel Oil ◽  
Stage Combustion ◽  
Two Stages ◽  
Power Boiler ◽  
Thermal Power Engineering

Coal is one of the main energy resources and development of new promising technologies on its basis is certainly topical. This article discusses the use of new technology of gas and fuel oil replacement by mechanically activated micronized coal in power engineering: ignition and stabilization of pulverized coal flame combustion, as well as gasification of micronized coal in the flow. The new technology coal combustion with two stages of grinding is suggested. Optimization of the scheme of two-stage combustion is calculated. The first experimental data on the combustion process are obtained. The first demonstration tests on gas and heavy oil replacement by micronized coal during boiler ignition were carried out in the real power boiler with the capacity of 320 tons of steam per hour.

scholarly journals Dispersed Two-Phase Flow Modelling for Nuclear Safety in the NEPTUNE_CFD Code

2017 ◽  
Vol 2017 ◽  
pp. 1-41
Author(s):  
Stephane Mimouni ◽  
William Benguigui ◽  
Solène Fleau ◽  
Arnaud Foissac ◽  
Mathieu Guingo ◽  
...  
Keyword(s):  
Power Systems ◽  
Nuclear Reactor ◽  
Thermal Power ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Vapor Condensation ◽  
Nuclear Safety ◽  
Two Phase ◽  
Boiling Crisis ◽  
Pressure Profiles

The objective of this paper is to give an overview of the capabilities of Eulerian bifluid approach to meet the needs of studies for nuclear safety regarding hydrogen risk, boiling crisis, and pipes and valves maintenance. The Eulerian bifluid approach has been implemented in a CFD code named NEPTUNE_CFD. NEPTUNE_CFD is a three-dimensional multifluid code developed especially for nuclear reactor applications by EDF, CEA, AREVA, and IRSN. The first set of models is dedicated to wall vapor condensation and spray modelling. Moreover, boiling crisis remains a major limiting phenomenon for the analysis of operation and safety of both nuclear reactors and conventional thermal power systems. The paper aims at presenting the generalization of the previous DNB model and its validation against 1500 validation cases. The modelling and the numerical simulation of cavitation phenomena are of relevant interest in many industrial applications, especially regarding pipes and valves maintenance where cavitating flows are responsible for harmful acoustics effects. In the last section, models are validated against experimental data of pressure profiles and void fraction visualisations obtained downstream of an orifice with the EPOCA facility (EDF R&D). Finally, a multifield approach is presented as an efficient tool to run all models together.

Gasify Micro-Oil Ignition Technology Based on Level Set Methods

2012 ◽  
Vol 497 ◽  
pp. 387-391
Author(s):  
Bei Wang ◽  
Yi Xie ◽  
Jian Guo Xiong
Keyword(s):  
Level Set ◽  
Oil And Gas ◽  
Two Phase Flow ◽  
Thermal Power ◽  
Level Set Methods ◽  
Fuel Load ◽  
Phase Flow ◽  
Two Phase ◽  
Coal Particles ◽  
Thermal Power System

In order to improve the Micro-oil ignition and low fuel load stable combustion in the thermal power system, the standard k-ε model is used in the analysis of flow field for studying the character of the mixture of coal particles, oil and gas mixture. The trajectories of two-phase flow are simulated by the Level Set Methods (LSM). The results describe the velocity distribution of the X-axis of the two-phase flow, concentration and track of coal particles, the thermal distribution of mixed fluid in the combustion chamber. It provides a theoretical basis for the further study of Micro-oil ignition technology

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