scholarly journals Thermodynamic and Chemical Analysis of Water-Coal Fuel Ignition and Combustion in Adiabatic Combustion Chamber

2021 ◽  
pp. 385-398
Author(s):  
Viktor I. Karpenok ◽  
Vasily I. Murko ◽  
Vera P. Mastikhina ◽  
Yulia A. Loboda
Keyword(s):  
Water Vapor ◽  
Solid Phase ◽  
Equilibrium Constants ◽  
Combustion Process ◽  
Ash Content ◽  
Volatile Substances ◽  
Leading Role ◽  
Coal Fuel ◽  
Coal Particles ◽  
Ignition And Combustion

The article presents results of improvement of physicochemical model of coal-water fuel ignition and combustion processes, taking into account ash content and release of volatile substances of solid phase. In this case, model of ignition and combustion of two systems of atomized coal-water fuel: drops and pure coal particles is taken as a basis. As a result of the analysis, the influence of ash content of coal-water fuel on output of combustible gases and content of water vapor in furnace atmosphere was established. Based on comparison of the diffusion coefficients of gases and the calculated values of equilibrium constants of reaction in combustion zone, conclusion has been of the leading role of water vapor oxidation of carbon in vortex adiabatic furnace. Performed numerical calculations have shown that combustion process of the above inhomogeneous systems (droplets and particles) in an adiabatic furnace within a short time becomes identical. Concentrations of volatile substances, oxygen (O2) and carbon dioxide (CO2) in various sections of the furnace have been established

scholarly journals Laboratory and industrial studies of gas coal ignition and combustion using high-voltage AC plasmatron

2020 ◽  
pp. 211-211
Author(s):  
Evgenii Butakov ◽  
Anatoliy Burdukov
Keyword(s):  
High Voltage ◽  
Combustion Process ◽  
Experimental Studies ◽  
Industrial Applications ◽  
Thermal Capacity ◽  
Fuel Oil ◽  
Experimental Sample ◽  
Coal Fuel ◽  
Start Up ◽  
Ignition And Combustion

This paper presents experimental studies and industrial applications of a promising method for igniting and combusting coal fuel using a high-voltage AC plasmatron. Experimental studies were carried out at a setup with a thermal capacity of up to 5 MW. Kuznetsk long flame coal selected after a ball-drum mill with sieve residue R90 = 15%, was taken as an experimental sample. The first experimental data on implementation of the combustion process have been obtained. Introduction and first industrial tests of the high-voltage AC plasmatron were carried out using a real power boiler TP-10 with an output capacity of 220 tons of steam per hour with gas and fuel oil replacement by coal during the process of boiler start-up.

scholarly journals Combustion peculiarities of coal-methane-air mixtures in a recuperative burner

2018 ◽  
Vol 243 ◽  
pp. 00007
Author(s):  
Leonid Minkov ◽  
Kseniya Moiseeva
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Water Vapor ◽  
Reaction Zone ◽  
Volatile Matter ◽  
Oxidation Reactions ◽  
Volatile Substances ◽  
Fine Coal ◽  
Coal Particles ◽  
Roll Type

Numerical modeling of the combustion of a lean methane-air mixture containing fine coal particles entering the “Swiss-roll” type recuperative burner is considered. The mathematical model is constructed under the following assumptions: the flow field is two-dimensional; the gas mixture is an ideal incompressible gas consisting of oxygen, methane, coal volatile substances, carbon monoxide, carbon dioxide, water vapor, hydrogen and nitrogen. In the gas phase four oxidation reactions, in which methane, volatile matter of coal, carbon monoxide, hydrogen participate and the reaction of carbon dioxide decomposition take place. On the surface of the coal particle, there are three oxidation reactions involving oxygen, carbon dioxide and water vapor, resulting in the formation of carbon monoxide. It is assumed that coal contains 8% of ash, 12.9% of volatile substances and 79.1% of carbon. It is shown that for a two percent methane-air mixture the reaction zone shifts toward the center of the burner as the feed rate of the mixture increases. An increase in the content of coal particles leads to a shift of the reaction zone into the inlet part of the burner, and the heat release in the burner increases.

scholarly journals Use of a heated graphite scrubber as a means of reducing interferences in UV-absorbance measurements of atmospheric ozone

2017 ◽  
Vol 10 (6) ◽  
pp. 2253-2269 ◽  
Author(s):  
Andrew A. Turnipseed ◽  
Peter C. Andersen ◽  
Craig J. Williford ◽  
Christine A. Ennis ◽  
John W. Birks
Keyword(s):  
Water Vapor ◽  
Solid Phase ◽  
Mercury Vapor ◽  
Packed Bed ◽  
The United States ◽  
Voc Adsorption ◽  
Clean Air ◽  
Smog Chambers ◽  
Equivalent Method ◽  
Ambient Measurements

Abstract. A new solid-phase scrubber for use in conventional ozone (O3) photometers was investigated as a means of reducing interferences from other UV-absorbing species and water vapor. It was found that when heated to 100–130 °C, a tubular graphite scrubber efficiently removed up to 500 ppb ozone and ozone monitors using the heated graphite scrubber were found to be less susceptible to interferences from water vapor, mercury vapor, and aromatic volatile organic compounds (VOCs) compared to conventional metal oxide scrubbers. Ambient measurements from a graphite scrubber-equipped photometer and a co-located Federal equivalent method (FEM) ozone analyzer showed excellent agreement over 38 days of measurements and indicated no loss in the scrubber's ability to remove ozone when operated at 130 °C. The use of a heated graphite scrubber was found to reduce the interference from mercury vapor to ≤ 3 % of that obtained using a packed-bed Hopcalite scrubber. For a series of substituted aromatic compounds (ranging in volatility and absorption cross section at 253.7 nm), the graphite scrubber was observed to consistently exhibit reduced levels of interference, typically by factors of 2.5 to 20 less than with Hopcalite. Conventional solid-phase scrubbers also exhibited complex VOC adsorption and desorption characteristics that were dependent upon the relative humidity (RH), volatility of the VOC, and the available surface area of the scrubber. This complex behavior involving humidity is avoided by use of a heated graphite scrubber. These results suggest that heated graphite scrubbers could be substituted in most ozone photometers as a means of reducing interferences from other UV-absorbing species found in the atmosphere. This could be particularly important in ozone monitoring for compliance with the United States (U.S.) Clean Air Act or for use in VOC-rich environments such as in smog chambers and monitoring indoor air quality.

scholarly journals Influence of polyvinyl alcohol fiber and fly ash content on compressive creep properties of high ductility cementitious composites

2021 ◽  
Vol 272 ◽  
pp. 02014
Author(s):  
Bo Chen ◽  
Liping Guo ◽  
Lihui Zhang ◽  
Wenxiao Zhang ◽  
Yin Bai ◽  
...  
Keyword(s):  
Fly Ash ◽  
Polyvinyl Alcohol ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Ash Content ◽  
Creep Model ◽  
High Ductility ◽  
Fiber Volume ◽  
Leading Role ◽  
Pva Fiber

The influence of polyvinyl alcohol (PVA) fiber volume fraction and fly ash content on the creep behavior of high ductility cementitious composites (HDCC) under compression was investigated. For this investigation, the creep behavior of four HDCC groups with cube compressive strength of 30–50 MPa, PVA fiber volume fraction of 1.5% and 2.0%, and fly ash content of 60% and 80% at 7 d and 28 d loading periods, respectively, were evaluated. A compressive creep model, which reflects the loading age and holding time, was established. The results revealed that when the load was applied at 7 d and 28 d, and then maintained for 245 d, the specific creep of HDCC ranged from 95×10-6/ MPa to 165×10-6/ MPa and from 59×10-6/ MPa to 135 × 10−6/ MPa, respectively. The corresponding creep coefficients ranged from 1.48 to 2.25 and from 1.10 to 1.94, respectively. The PVA fiber volume fraction and fly ash content were the main factors affecting the specific creep of HDCC, which increased with increasing fiber fraction and fly ash content. Under short-term loading, the fiber volume fraction played a leading role in the specific creep, and the fly ash content played the leading role during long-term loading. Furthermore, the specific creep and creep coefficient decreased significantly with increasing loading age. The classical creep model described by a power exponent function is suitable for HDCC.

Effects of Soybean Pectin Gel on Flavor Compounds Variation of Cheddar Cheeses during Ripening

2014 ◽  
Vol 881-883 ◽  
pp. 797-800
Author(s):  
He Liu ◽  
Jun Li ◽  
Ping Geng ◽  
Yu Tang He ◽  
Tao Ma
Keyword(s):  
Volatile Compounds ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Cheddar Cheese ◽  
Flavor Compounds ◽  
Volatile Substances ◽  
Pectin Gel ◽  
High Concentrations

In this manuscript, flavor compounds development of Cheddar Cheese with addition of soybean pectin gel was investigated during ripening. A rapid and simple Solid-Phase Microextraction (SPME) procedure was used for identifying and classifying the volatile compounds. The result showed that addition of soybean pectin gel to cheese had similar flavor profiles with full-fat cheeses. Higher levels of acid volatile compounds and aldehydes were obtained in comparison with experimental cheese. Results simultaneously indicated that experimental cheeses contained high concentrations of volatile amine as soybean pectin gel promoting the volatile substances.

scholarly journals A Review of Pyrolisis of Eceng Gondok (Water hyacinth) for Liquid Smoke

2018 ◽  
Vol 73 ◽  
pp. 05010
Author(s):  
Rita Dwi Ratnani ◽  
Widiyanto
Keyword(s):  
Acetic Acid ◽  
Water Vapor ◽  
Activated Charcoal ◽  
Water Hyacinth ◽  
Combustion Process ◽  
Pyrolysis Process ◽  
Temperature Range ◽  
Liquid Smoke ◽  
16Th World ◽  
Co Gas

The growth of eceng gondok (Water hyacinth) in Rawa Pening Lake showed rapid increase.. Based on the mandate of the National Lake conference in Bali and the 16th World Lake Conference, Rawa Pening is one of the fifteen national lakes which need to be treated for its conservation. Reducing number of eceng gondok plants is one of the alternatif. However, further processing is required to treat the waste of eceng gondok. One attempt is to convert eceng gondok (water hyacinth) into liquid smoke product. This article reviewes the potency of eceng gondok for liquid smoke through pyrolisis method. The liquid smoke can be used for various applications such as preservatives, antioxidants, biopesticides and perisa disinfectants. Pyrolysis is a combustion process in the absence of oxygen to produce liquid and charcoal activated charcoal products called activated charcoal. The pyrolysis process is generally carried out at a temperature range between 200-700 °C. The pyrolysis process is one of the methods chosen in order to strive for development that suppresses the formation of CO gas but releases water vapor. Pyrolysis at a temperature of 300-700 ° C, produces the most dominant compounds 1.6 Anhyro-beta-d-glucopyranose, phenol, and acetic acid. The reaction that occurs during pyrolysis of this temperature is the release of water vapor instead of carbon gas so that it is safe for the environment. The discussion on this article focused on the production of liquid smoke from eceng gondok biomass.

The Main Regularities of Ignition and Combustion of Coal-Water Fuels Produced from Fat, Non-Baking Coal and Anthracite

2018 ◽  
Vol 38 ◽  
pp. 67-78 ◽  
Author(s):  
Valeriya Pinchuk
Keyword(s):  
Experimental Data ◽  
Data Processing ◽  
Experimental Research ◽  
Combustion Process ◽  
Medium Temperature ◽  
Experimental Data Processing ◽  
Ignition And Combustion ◽  
Temperature Correlations

For the purpose of defining the regularities of CWF combustion in the air, we have conducted experimental research into ignition and combustion of the fuels produced from coal of different metamorphic ranks. The studies allowed to obtain time-temperature correlations describing CWF ignition and combustion, to determine the stages of the combustion process, to define the structure of the ash coating, and the degree of the fuel combustible mass burnout. The present paper analyses the results of experimental research into the regularities underlying the processes of ignition and combustion for CWF (fat coal), CWF (non-baking coal), and CWF (anthracite).It was established that the oven medium temperature affects the duration of every CWF combustion stage, which was substantiated by the relevant dependencies resulting from the experimental data processing.

scholarly journals Analysis of the efficiency of a solid fuel boiler depending on the choice of combusted fuel

2020 ◽  
Vol 154 ◽  
pp. 02003
Author(s):  
Grzegorz Pełka ◽  
Wojciech Luboń ◽  
Przemysław Pachytel
Keyword(s):  
Energy Efficiency ◽  
Solid Fuel ◽  
Combustion Process ◽  
Calorific Value ◽  
Volatile Matter ◽  
Ash Content ◽  
Solid Fuels ◽  
The Real ◽  
Residential Sector

In the municipal and residential sector in Poland, as many as 50% of households are heated by solid fuel boilers. Most often these are, unfortunately, inefficient boilers, fired with low-quality coal. This study characterizes the market of boilers for solid fuels in Poland, and also presents the main apportionment of these devices, due to the different criteria that characterize them. The current legal changes in the scope of energy and emission requirements for solid fuel boilers are also discussed. The main purpose of this work is to analyze the real efficiency of the solid fuel over-fired boiler used, depending on the fuel burned in it. The process of burning selected fuels (seasoned wood, coal and pea coal) in the boiler was preceded by tests of these fuels to determine their energy parameters, such as moisture, ash content, the share of volatile matter and calorific value. In the next step, the energy efficiency obtained by the tested solid fuel boiler during the combustion of selected solid fuels was compared. The highest efficiency was achieved during the combustion of pea coal, and the lowest was achieved during the combustion of wood. In any case, the nominal efficiency value was achieved. Solutions that could improve the quality of the combustion process in this type of boiler were proposed.

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.

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