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Journal articles on the topic 'Combustion gases'
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1
Prada, Abelardo, and Caroll E. Cortés. "La descomposición térmica de la cascarilla de arroz: Una alternativa de aprovechamiento integral." Orinoquia 14, no. 2 sup (December 1, 2010): 155–70. http://dx.doi.org/10.22579/20112629.103.
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RESUMEN: El presente trabajo se orientó a capturar los gases de combustión de la cascarilla de arroz para transformarlos en carbonato de calcio (CaCO ), sustancia útil en labores agrícolas. Se demostró que los gases de combustión de la cascarilla pueden ser capturados en soluciones acuosas de KOH y NaOH, de las cuales se obtiene CaCO con la adición de CaCl2 en solución acuosa Se determinaron las características del proceso de combustión (masa de cascarilla, temperatura y masa de ceniza), de la captura de los gases (tiempo de reacción, pH y t, (ºC)), de la precipitación del CaCO (masa de CaCl2 requerida) y la masa de CaCO obtenido.Palabras clave: Combustión, aprovechamiento integral, captura de dióxido de carbono, carbonato de calcio, uso agrícola.SUMMARY: The present work was aimed at capturing the gases of combustion of rice husk to transform them into calcium carbonate (CaCO ), a substance useful in agriculture It was shown that the combustion gases from the rice husk can be captured in aqueous solutions of KOH and NaOH, of which CaCO3 is obtained by adding CaCl2 aqueous. Characteristics were determined from the combustion process (mass scale, temperature and mass of ash) of the capture of gases (reaction time, pH and t ° C), the precipitation of CaCO3 (mass of CaCl2 required) and the mass CaCO obtained.Key words: Combustion, integral use, capture of carbon dioxide, calcium carbonate, land use
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Vitázek, I., J. Klúčik, D. Uhrinová, Z. Mikulová, and M. Mojžiš. "Thermodynamics of combustion gases from biogas." Research in Agricultural Engineering 62, Special Issue (December 28, 2016): S8—S13. http://dx.doi.org/10.17221/34/2016-rae.
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Biogas as a respected source of renewable energy is used in various areas for heating or in power cogeneration units. It is produced by anaerobic fermentation of biodegradable materials. The utilization of biogas is wide – from process of combustion in order to obtain thermal energy, combined heat and power production, gas combustion engines, micro turbines or fuel cells up to trigeneration. Biogas composition depends on the raw material. The aim of this paper was to develop a new methodology; according to this methodology, by means of gas mixture thermodynamics and tabular exact parameters of individual gaseous components, all the necessary thermodynamic and operating values of biogas composition were calculated. The mathematical model of biogas combustion was elaborated. For an accurate realization of calculation, a computing program was designed.
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Howard, J. R. "Deposition from combustion gases." Heat Recovery Systems and CHP 10, no. 3 (January 1990): 297. http://dx.doi.org/10.1016/0890-4332(90)90010-h.
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Ozturk, Suat. "A Numerical Investigation on Emissions of Partially Premixed Shale Gas Combustion." International Journal of Heat and Technology 38, no. 3 (October 15, 2020): 745–51. http://dx.doi.org/10.18280/ijht.380319.
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The adiabatic, turbulent, and partially premixed combustions of several shale gases and air in a co-axial type combustor are computationally examined under the effects of different equivalence ratios, inlet temperatures, flow rates, humidity ratios, pressure, oxid inlet temperatures and flow rates, and swirl velocities in this study. Shale gases are extracted from Barnette, New Albany, Fayetteville, and Haynesville areas of USA. ANSYS software is used for numerical calculations of combustion. Results show that the maximum NO emissions for Barnette, New Albany, Fayetteville, and Haynesville shale gas occur at the equivalence ratio of 1.42, 1.41, 1.4, and 1.39. The rising fuel inlet temperature increase NO and reduces CO emissions after 300 K. The increasing humidity ratio causes NO and CO mass fractions to decrease. The ascending pressure raises NO up to 4 bar and lowers CO emissions. The increasing oxid flow rate abates the mass fractions of both NO and CO. The rising swirl velocity escalates NO up to 15 m/s and decreases CO emissions for all the shale gas combustions.
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Alturaihi, Muna Hameed, Mahmoud Atallah Mashkour, and Sanaa Turki Mousa AL-Musawi. "Effects of Hydrogen and Nitrogen Concentration on Laminar Burning Velocities and NO, CO Formation of Propane-Air Mixtures." Mathematical Modelling of Engineering Problems 9, no. 4 (August 31, 2022): 1131–35. http://dx.doi.org/10.18280/mmep.090432.
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With the development of the uses of hydrocarbon compounds in many industrial fields, especially in the field of energy liberation through oxidation of gases, as previous research specialized in improving the combustion processes of gases by adding particles of other gases that contribute to improving the combustion of these compounds in terms of temperatures and speed of flame combustion. The previous study aimed to improve the flame speed by adding different gases to several compounds. In this research paper, propane gas C3H8 is used as the main gas to improve its combustion properties. N2 and H2 gas were added in different proportions, through which a clear effect on the combustion properties can be seen in terms of combustion speed. Flames and exhaust as CO and NOx. As the auxiliary gases were added in this improvement at rates of 20%, 30% and 40%, and then these tests were analyzed, where it was concluded that H2 gas clearly contributed to improving the combustion speed of the flame, as the flame combustion velocity reached 58.3 cm/s by 40%.
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Isvoranu, Dragos D., and Paul G. A. Cizmas. "Numerical Simulation of Combustion and Rotor-Stator Interaction in a Turbine Combustor." International Journal of Rotating Machinery 9, no. 5 (2003): 363–74. http://dx.doi.org/10.1155/s1023621x03000344.
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This article presents the development of a numerical algorithm for the computation of flow and combustion in a turbine combustor. The flow and combustion are modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species-conservation equations. The chemistry model used herein is a two-step, global, finite-rate combustion model for methane and combustion gases. The governing equations are written in the strong conservation form and solved using a fully implicit, finite-difference approximation. The gas dynamics and chemistry equations are fully decoupled. A correction technique has been developed to enforce the conservation of mass fractions. The numerical algorithm developed herein has been used to investigate the flow and combustion in a one-stage turbine combustor.
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Variny, Miroslav, Augustín Varga, Miroslav Rimár, Ján Janošovský, Ján Kizek, Ladislav Lukáč, Gustáv Jablonský, and Otto Mierka. "Advances in Biomass Co-Combustion with Fossil Fuels in the European Context: A Review." Processes 9, no. 1 (January 5, 2021): 100. http://dx.doi.org/10.3390/pr9010100.
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Co-combustion of biomass-based fuels and fossil fuels in power plant boilers, utility boilers, and process furnaces is a widely acknowledged means of efficient heat and power production, offering higher power production than comparable systems with sole biomass combustion. This, in combination with CO2 and other greenhouse gases abatement and low specific cost of system retrofit to co-combustion, counts among the tangible advantages of co-combustion application. Technical and operational issues regarding the accelerated fouling, slagging, and corrosion risk, as well as optimal combustion air distribution impact on produced greenhouse gases emissions and ash properties, belong to intensely researched topics nowadays in parallel with the combustion aggregates design optimization, the advanced feed pretreatment techniques, and the co-combustion life cycle assessment. This review addresses the said topics in a systematic manner, starting with feed availability, its pretreatment, fuel properties and combustor types, followed by operational issues, greenhouse gases, and other harmful emissions trends, as well as ash properties and utilization. The body of relevant literature sources is table-wise classified according to numerous criteria pertaining to individual paper sections, providing a concise and complex insight into the research methods, analyzed systems, and obtained results. Recent advances achieved in individual studies and the discovered synergies between co-combusted fuels types and their shares in blended fuel are summed up and discussed. Actual research challenges and prospects are briefly touched on as well.
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R. Bungay, Henry. "Waste Combustion Gases and Algae." Current Biotechnology 2, no. 1 (February 12, 2013): 59–63. http://dx.doi.org/10.2174/2211550111302010010.
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Takeno, Tadao. "Physics of Combustion of Gases." Combustion and Flame 64, no. 1 (April 1986): 125. http://dx.doi.org/10.1016/0010-2180(86)90103-3.
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Levytska, Olena Hryhoriivna, Yulia Vladimirovna Voytenko, and Anastasiia Oleksiivna Orishechok. "COMPARATIVE ASSESSMENT OF GASEOUS FUEL EMISSION." Bulletin of the National Technical University "KhPI". Series: Chemistry, Chemical Technology and Ecology, no. 1(5) (May 15, 2021): 83–91. http://dx.doi.org/10.20998/2079-0821.2021.01.13.
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The work presents estimated comparative assessment of emissions release in combustion products during work of high–power steam boilers with the use of traditional fuel – natural gas and alternative fuels – blast–furnace and coke–oven gases generated in the process of technological cycle at iron and steel and coke–chemical enterprises. Calculation algorithm is shown and formulas for assessment of carbon content in exhaust gases are defined, conclusions on ecological efficiency of gaseous fuels are given.
The purpose of the work was to evaluate the emissions of harmful substances generated during the combustion of natural, blast furnace and coke oven gases, justification of the calculation of carbon content of a given chemical composition and determine the optimal environmental impact of analogues of natural gas.
The comparative estimation of pollutant emissions into atmospheric air during combustion of natural, coke oven and blast furnace gases revealed:
– high sulfur dioxide emissions from combustion of blast furnace and coke oven gases due to the presence of sulfur compounds in the composition of these gases;
– relatively high emissions of nitrogen compounds for natural and coke oven gases and relatively low emissions for blast furnace gas;
– сarbon emissions are high for all types of fuels which have been considered, most carbon dioxide gets into the air when burning natural gas, least – when burning blast furnace gas;
– significantly higher methane emissions are observed during the combustion of natural and coke oven gases, respectively, smaller – for blast–furnace gas combustion;
– coke oven and natural gases are characterized by low mercury emissions.
Comparative assessment of the calculated values of hazardous substances emissions in the combustion products in the process of combustion of natural, coke–oven and blast–furnace gases shows that even at lower working heat of combustion values the coke–oven and blast–furnace gases can compete with natural gas.
For the first time, a comparative characterization of the emissions of harmful substances in the combustion of natural, coke oven and blast furnace gases is presented, and it is shown that the gases used in coke and metallurgical industries, which are used as analogues of natural, are logical to use, but require the installation of treatment systems. The paper defines a formula for calculating the carbon content in natural gas from the Urengoy–Uzhhorod gas pipeline. The provided calculations and the introduction of simplified formulas serve as an example for the calculation of emission factors and emissions in assessing the level of safety of existing equipment and can be used in the development of permit documents of enterprises that carry out emissions of harmful substances to the environment.
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Gulyurtlu, I., T. Crujeira, M. H. Lopes, P. Abelha, D. Boavida, J. Seabra, R. Gonçalves, C. Sargaço, and I. Cabrita. "The Study of Combustion of Municipal Waste in a Fluidized Bed Combustor." Journal of Energy Resources Technology 128, no. 2 (January 30, 2006): 123–28. http://dx.doi.org/10.1115/1.2191507.
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The combustion behavior of municipal solid waste was studied in a pilot fluidized bed combustor. The waste was pelletized prior to its use. Both co-firing with coal and combustion of waste alone were under taken. The combustion studies were carried out on the pilot installation of INETI. The fluidized bed combustor is square in cross section with each side being 300mm long. Its height is 5000mm. There is a second air supply to the freeboard at different heights to deal with high volatile fuels. There was a continuous monitoring of the temperatures in the bed, as well as the composition of the combustion gases. The combustion gases leaving the reactor were let go through the recycling cyclone first to capture most of particulates elutriated out of the combustor. There was a second cyclone, which was employed with the aim of increasing the overall efficiency of collecting solid particles. The gaseous pollutants leaving the stack were sampled under isokinetic conditions for particulate matter, chlorine compounds, and heavy metals. The ash streams were characterized for heavy metals. The results obtained were compared with national legislation. The results obtained suggest that (i) the combustion efficiency was very high, (ii) there was an enrichment of ashes with heavy metals in the cyclones compared to the bed material, (iii) in general, the flue gas emissions were below the permited limits, and (iv) for the compliance with the new European directive for stricter emission limits adequate control devices, like bag filters, should be integrated with refuse derived fuel (RDF) combustion.
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Yang, Fan, Shengji Li, Xunjie Lin, Jiankan Zhang, Heping Li, Xuefeng Huang, and Jiangrong Xu. "Vaporization, Diffusion and Combustion of Laser-Induced Individual Magnesium Microparticles in Inert and Oxidizing Atmospheres." Processes 9, no. 11 (November 17, 2021): 2057. http://dx.doi.org/10.3390/pr9112057.
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Although the gas phase combustion of metallic magnesium (Mg) has been extensively studied, the vaporization and diffusive combustion behaviors of Mg have not been well characterized. This paper proposes an investigation of the vaporization, diffusion, and combustion characteristics of individual Mg microparticles in inert and oxidizing gases by a self-built experimental setup based on laser-induced heating and microscopic high-speed cinematography. Characteristic parameters like vaporization and diffusion coefficients, diffusion ratios, flame propagation rates, etc., were obtained at high spatiotemporal resolutions (μm and tens of μs), and their differences in inert gases (argon, nitrogen) and in oxidizing gases (air, pure oxygen) were comparatively analyzed. More importantly, for the core–shell structure, during vaporization, a shock wave effect on the cracking of the porous magnesium oxide thin film shell-covered Mg core was first experimentally revealed in inert gases. In air, the combustion flame stood over the Mg microparticles, and the heterogeneous combustion reaction was controlled by the diffusion rate of oxygen in air. While in pure O2, the vapor-phase stand-off flame surrounded the Mg microparticles, and the reaction was dominated by the diffusion rate of Mg vapor. The diffusion coefficients of the Mg vapor in oxidizing gases are 1~2 orders of magnitude higher than those in inert gases. However, the diffusive ratios of condensed combustion residues in oxidizing gases are ~1/2 of those in inert gases. The morphology and the constituent contents analysis showed that argon would not dissolve into liquid Mg, while nitrogen would significantly dissolve into liquid Mg. In oxidizing gases of air or pure O2, Mg microparticles in normal pressure completely burned due to laser-induced heating.
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Shin, Jeong-Seon, Dowon Shun, Churl-Hee Cho, and Dal-Hee Bae. "A Study on the Co-Combustion Characteristics of Coal and Bio-SRF in CFBC." Energies 16, no. 4 (February 16, 2023): 1981. http://dx.doi.org/10.3390/en16041981.
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Bio-SRF based on livestock waste has low heating value and high moisture content. The concentration of toxic gases such as SOx, NOx, and HCl in the flue gas is changed according to the composition of fuel, and it has been reported. Therefore, the study of fuel combustion characteristics is necessary. In this study, we investigated combustion characteristics on the blended firing of coal and Bio-SRF (bio-solid refused fuel) made from livestock waste fuel in CFBC (circulating fluidized bed combustor). The raw materials for manufacturing Bio-SRF include agricultural waste, herbaceous plants, waste wood, and vegetable residues. Bio-SRF, which is formed from organic sludge, has a low heating value and a high moisture content. Bio-SRF of livestock waste fuel is blended with different ratios of coal based on heating values when coal is completely combusted in CFBC. In the result of experiment, the combustor efficiency of calculated unburned carbon concentration in the fly ash shows 98.87%, 99.04%, 99.64%, and 99.71% when the multi co-combustion ratio of livestock waste fuel increased from 100/0 (coal/livestock waste) to 70/30 (coal/livestock waste). In addition, the boiler efficiency is shown to be 86.23%, 86.30%, 87.24% and 87.27%. Through the experimental results, we have identified that co-combustion of livestock waste fuel does not affect boiler efficiency. We have systematically investigated and discussed the temperature changes of the internal combustor, compositions of flue gases, solid ash characteristics, and the efficiency of combustion and of the boiler during co-combustion of coal and Bio-SRF.
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Mishina, K. A. Mishina, E. N. Korchagina, and Ia V. Kazartsev. "Metrological Assurance of Gas Calorimeter and Wobbe Index Analyser." Measurement Standards. Reference Materials 17, no. 2 (August 10, 2021): 19–32. http://dx.doi.org/10.20915/2687-0886-2021-17-2-19-32.
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The paper describes research on metrological assurance of such measuring instruments as gas calorimeters and Wobbe index analysers. The purpose of the performed research is development of reference materials for gases with certified value of net volume-basis calorific value traceable to Russian state primary standard. Input set of candidate gases is hydrogen, methane, ethane and propane, as well as the target uncertainty of lower volumetric combustion energy value equal to 0,3 % – both were selected basing on results of metrological characteristics analysis of calorimetric equipment. The certified value of lower volumetric combustion energy is traceable to the State Primary Standard of combustion energy, specific combustion energy and volumetric combustion energy units GET 16. The certified value of selected gases and the uncertainty of this value were estimated with usage of comparing calorimeters for the combustion of high- and low-calorie gases «USVG» and «USNG» included in GET 16. Results obtained during investigational study and reference materials characterisation confirmed the stated accuracy. The continuance in prospect may allow development of reference materials for gas imitating mixtures of natural and casing-head gases as well as include Wobbe index in the list of certified characteristics.
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Minaev, S. S., S. I. Potytnyakov, and V. S. Babkin. "Combustion wave instability in the filtration combustion of gases." Combustion, Explosion, and Shock Waves 30, no. 3 (May 1994): 306–10. http://dx.doi.org/10.1007/bf00789421.
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Wang, Yan-Ming, Wen-Zheng Wang, Zhen-Lu Shao, De-Ming Wang, and Guo-Qing Shi. "TERAHERTZ MEASUREMENT OF INDICATOR GAS EMISSION FROM COAL SPONTANEOUS COMBUSTION AT LOW TEMPERATURE." Ecological Chemistry and Engineering S 20, no. 4 (December 1, 2013): 709–18. http://dx.doi.org/10.2478/eces-2013-0049.
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Abstract Coal spontaneous combustion is an extremely complicated physical and chemical changing process. In order to improve the indicator gases detection technology and coal spontaneous combustion monitoring, a novel forecast method for toxic gases emission from coal oxidation at low temperature is presented in this paper. The experiment system is setup combined with frequency-domain terahertz technology and coal temperature programming device. The concentration curves of carbon monoxide and sulphur dioxide gases from coal spontaneous combustion are estimated according to molecule terahertz spectra. The influences of coal rank and oxygen supply on coal spontaneous combustion characteristics are discussed. Both carbon monoxide and sulphur dioxide gases absorption spectra show the characteristic equi-spaced absorption peaks. Results demonstrate that under the condition of lean oxygen, there exists a critical oxygen concentration in the process of coal oxidation at low temperature. Comparing with Fourier infrared spectrum testing, the presented method is highly accurate and more sensitive, especially suitable for early-stage monitoring of the indicator gases produced by coal spontaneous combustion.
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Jankowski, Antoni, and Mirosław Kowalski. "Alternative fuel in the combustion process of combustion engines." Journal of KONBiN 48, no. 1 (December 1, 2018): 55–81. http://dx.doi.org/10.2478/jok-2018-0047.
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Abstract The article analyses the impact of emulsified fuel, containing H2O2 hydrogen peroxide, on the emissions of nitrogen oxides and diesel engine smoke. The process of forming toxic components in exhaust gases of reciprocating engines during the engine operation, and the relationship that specifies the hydrogen peroxide decomposition process were presented. The research was carried out with the use of fuel containing 30%, 20% and 10% of hydrogen peroxide. The concentration courses of the nitric oxide (NO) and nitrogen oxides (NOx), as well as the (CO) carbon monoxide concentration and (S) engine smoke courses were shown separately for the external characteristics of the engine. Finally, the importance of knowledge related to the mechanisms of generation of toxic components in exhaust gases in the reciprocating engines was emphasised.
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Castro, Zamir Sánchez, Hugo Reinel García Bernal, and Oscar Andrés Mendieta Menjura. "Efecto del precalentamiento del aire primario y la humedad del bagazo de caña de azúcar durante la combustión en lecho fijo." Corpoica Ciencia y Tecnología Agropecuaria 14, no. 1 (May 24, 2013): 5. http://dx.doi.org/10.21930/rcta.vol14_num1_art:263.
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<p>Los hornos utilizados para la elaboración de panela presentan pérdidas energéticas debido a una combustión incompleta del bagazo de caña de azúcar y al calor sensible en los gases de chimenea. Durante el proceso de producción de panela, el bagazo de caña de azúcar se utiliza como combustible, con fracciones másicas de humedad entre 30% y 50%, las cuales afectan el rendimiento de la combustión de una biomasa en lecho fijo. Gracias a que el precalentamiento del aire disminuye el tiempo de secado, su implementación en muchos sistemas de combustión de biomasa ha incrementado la eficiencia del proceso. Por tanto, en la presente investigación se estudió la influencia del contenido de humedad y el precalentamiento del aire primario sobre la temperatura, la composición del gas y la tasa de combustión, mediante un diseño experimental factorial mixto 3x2. Los resultados demostraron que el aumento en la humedad del bagazo de caña reduce la tasa de combustión y la conversión de carbono a CO2, y por tanto, el rendimiento del proceso. Cuando se precalentó el aire primario hasta una temperatura de 120 ºC, la tasa de combustión aumentó, sin embargo sólo significó un incremento en el rendimiento de la combustión para una fracción másica de humedad de 30%.</p><p><strong>Effect of primary air preheating and moisture sugarcane bagasse during fixed bed combustion</strong></p><p>Furnaces used to making jaggery have energy losses due to incomplete combustion of sugarcane bagasse and sensible heat in the flue gases. During jaggery production process, sugarcane bagasse is used as fuel, with mass fractions of humidity between 30% and 50%, which affect the combustion efficiency of a biomass in a fixed bed. Because the air preheating decreases the drying time, its implementation in many biomass combustion systems increases process efficiency. Therefore, in this investigation we studied the influence of the moisture content and the preheating of the primary air on the combustion of bagasse in a fixed bed furnace, by analyzing the profiles of temperature and concentration of the combustion gas. Results showed that increasing in bagasse moisture reduces the rate of combustion and conversion of carbon to CO2, diminishing the yield of process. When the primary air is preheated to a temperature of 120 ºC, the combustion rate increased, however, only meant an increase in combustion efficiency to a mass fraction of 30% humidity.</p>
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Hosseini, Seyed, Evan Owens, John Krohn, and James Leylek. "Experimental Investigation into the Effects of Thermal Recuperation on the Combustion Characteristics of a Non-Premixed Meso-Scale Vortex Combustor." Energies 11, no. 12 (December 4, 2018): 3390. http://dx.doi.org/10.3390/en11123390.
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In small-scale combustors, the ratio of area to the combustor volume increases and hence heat loss from the combustor’s wall is significantly enhanced and flame quenching occurs. To solve this problem, non-premixed vortex flow is employed to stabilize flames in a meso-scale combustion chamber to generate small-scale power or thrust for propulsion systems. In this experimental investigation, the effects of thermal recuperation on the characteristics of asymmetric non-premixed vortex combustion are studied. The exhaust gases temperature, emissions and the combustor wall temperature are measured to evaluate thermal and emitter efficiencies. The results illustrate that in both combustors (with/without thermal recuperator), by increasing the combustion air mass flowrate, the wall temperature increases while the wall temperature of combustor with thermal recuperator is higher. The emitter efficiency calculated based on the combustor wall temperature is significantly increased by using thermal recuperator. Thermal efficiency of the combustion system increases up to 10% when thermal recuperator is employed especially in moderate Reynolds numbers (combustion air flow rate is 120 mg/s).
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Galashov, Nikolay N., Alexander A. Tubolev, Evgeny S. Boldushevsky, and Alexander A. Minor. "Impact of steam flow into a combustion chamber of a contact gas-steam installation on its energy characteristics." Bulletin of the Tomsk Polytechnic University Geo Assets Engineering 335, no. 2 (February 28, 2024): 48–59. http://dx.doi.org/10.18799/24131830/2024/2/4436.
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Relevance. Reduction of natural gas consumption and emissions of harmful substances into the environment based on introduction of water vapor into a combustion chamber of a contact gas-steam installation. Aim. To carry out numerical studies on the influence of relative steam flow into the combustion chamber of the contact gas-steam installation on its energy characteristics. Objects. Contact gas-steam installations based on gas turbines with steam injection into the combustion chamber. Methods. Numerical methods based on material and energy balances of systems and elements of gas-steam installations. Results. Based on the calculation of the thermal circuit of the contact gas-steam installation, the authors have studied the influence of the relative steam flow into the combustion chamber on its energy characteristics. It was determined that the absolute electrical efficiency of the contact gas-steam installation increases linearly with growth of relative steam flow into the combustion chamber. The range of changes in the relative steam flow into the combustion chamber strongly depends on the temperature of the gases behind the combustion chamber and the compression ratio in the air compressor; the smaller these parameters are, the greater the range of changes. The maximum efficiency of 56% for all options is achieved at the maximum relative steam flow into the combustion chamber. It was established that the excess air coefficient, depending on the relative steam flow rate, decreases linearly, and the higher the temperature of the gases behind the combustion chamber and the compression ratio in the air compressor, the greater the rate of decline and the smaller the range of changes in the relative steam flow rate. It was revealed that the efficiency coefficient strongly depends on the relative steam flow into the combustion chamber, the temperature of the gases behind it and the degree of compression in the air compressor; with increasing these parameters, it increases linearly. It was determined that the temperature of the gases at the outlet of the gas turbine also strongly depends on the relative flow of steam into the combustion chamber, the temperature of the gases at its outlet and the compression ratio in the compressor. With an increase in the relative flow of steam into the combustion chamber, this temperature increases linearly from 600 to 700°C, while the higher the temperature of the gases at the outlet of the combustion chamber and the compression ratio in the compressor, the higher the temperature of the gases at the outlet of the gas turbine. The authors revealed the dependence of useful work on a gas turbine shaft on the relative steam flow into the combustion chamber. With an increase in the relative steam flow, the useful work on the gas turbine shaft increases along the branch of the parabola. The higher the temperature of the gases behind the combustion chamber and the compression ratio in the compressor, the steeper the branch of the parabola, but the smaller the range of changes in the relative steam flow. It was established that with an increase in the relative steam flow, the gas flow to the gas turbine decreases according to a hyperbola. Moreover, the lower the temperature of the gases behind the combustion chamber and the compression ratio in the compressor, the more the gas flow to the gas turbine drops.
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Xiao, Hai Ping, Gao Yan Han, Yu Kun Dai, and Lin Dong. "Equilibrium Analysis on Sulfur Material in Oxyfuel Combustion." Advanced Materials Research 986-987 (July 2014): 67–71. http://dx.doi.org/10.4028/www.scientific.net/amr.986-987.67.
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To study migration and transformation of sulfur species in oxyfuel combustion, the study attempts to analyze distribution of sulfur compounds with thermodynamic equilibrium. Results show that sulfur-containing gases predominantly are SO2 and SO3, the maximum thermodynamic equilibrium concentration of those in oxyfuel combustion respectively increase by 3.4 and 4.5 times compared with the conventional combustion. Furthermore, SO2 gas formation rate decreases while SO3 increases under oxyfuel combustion. Sulfur-containing gases are generally more sensitive to temperature and excess air coefficient. The amount of sulfur compounds significantly increases in oxyfuel combustion.
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Calotă, Răzvan, Alina Girip, Sergiu Istrate, Anica Ilie, Mădălina Nichita, and Valentin Cublesan. "Aspects regarding the use of recovered energy for air conditioning." E3S Web of Conferences 111 (2019): 06013. http://dx.doi.org/10.1051/e3sconf/201911106013.
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In the paper the authors analyze the possibility of using the energy recovered from combustion gases, for air cooling. The objective is to evaluate the thermal potential of combustion gases from a cogeneration plant with a 3 MW electric power, located in Buzau. The monitoring data for the cogeneration system shows that the average flue gas temperature at the exit to the atmosphere is 125° C and the mass flow rate of the combustion gases is 18351 kg/h. The thermal potential of combustion gases isused for the preparation of hot water at 85°C for the operation of a LiBr-H2O solution absorption plant. Finally, the authors present a comparative study between the classic cooling system using chiller with mechanical vapor compression (VCM) and the absorption plant supplied by recovered energy from the cogeneration system, high lighting the advantage of the proposed trigeneration system.
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Osama, A. Marzouk. "Radiant Heat Transfer in Nitrogen-Free Combustion Environments." International Journal of Nonlinear Sciences and Numerical Simulation 19, no. 2 (April 25, 2018): 175–88. http://dx.doi.org/10.1515/ijnsns-2017-0106.
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AbstractWhen mathematically calculating the radiant heat flux during combustion, the radiant property of a gaseous mixture can be approximated as a weighted sum of the radiant properties of fictitious gases to give an equivalent effect of the actual gas mixture. This concept has been in use for many years. However, it was initially tailored to product gases in air-combustion environment. With the advent and progress in nitrogen-free combustion (particularly for environmental purposes), the chemical composition of the combustion gases is highly altered and existing models should be assessed for their suitability in these new environments. We carried out this task, which was motivated by our recent modeling work that revealed that a new model should be developed for nitrogen-free combustion environments. The model proposed here has four participating gases plus one transparent gas and its performance in predicting radiant heat transfer in 3D benchmark problems is evaluated in comparison with existing models, using the discrete-ordinate method for directional radiation domain combined with the finite-volume method of the spatial domain.
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Łapinski, Damian, and Janusz Piechna. "Improvements in the turbo-engine by replacement of conventional combustion chamber by a pulse combustion chamber." Archive of Mechanical Engineering 60, no. 4 (December 1, 2013): 481–94. http://dx.doi.org/10.2478/meceng-2013-0029.
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Abstract This paper comprises description of the turbo engine and evaluation of its analytical model. The analytical model was created to establish a benchmark for further evaluation of a wave rotor combustor (at constant volume). The wave rotor combustor concept was presented and discussed. Advantages of combustion at constant volume were described as well as the basic turbo engine updates required to reflect pulse combustor application. The calculation results for analytical model of a basic engine, and that equipped with pulse combustor are included in this paper. The paper describes the required changes in the engine structure and construction and the estimated thermodynamic improvements. Axial-type pulse multi-chamber combustion unit increasing the pressure and temperature of gases requires a special additional turbine utilizing additional energy and forming the interface between the standard compressor-turbine unit. Performance calculations done for an existing GTD-350 engine showed that constant-volume combustion process is valuable
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Zhang, Long, Shanshan Zhang, Hua Zhou, Zhuyin Ren, Hongchuan Wang, and Xiuxun Wang. "Efficient Combustion of Low Calorific Industrial Gases: Opportunities and Challenges." Energies 15, no. 23 (December 5, 2022): 9224. http://dx.doi.org/10.3390/en15239224.
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It is becoming increasingly important to develop effective combustion technologies for low calorific industrial gases (LCIG) because of the rising energy demand and environmental issues caused by the extensive use of fossil fuels. In this review, the prospect of these opportunity fuels in China is discussed. Then, the recent fundamental and engineering studies of LCIG combustion are summarized. Specifically, the differences between LCIG and traditional fuels in the composition and fundamental combustion characteristics are described. The state-of-the-art combustion strategies for burning LCIG are reviewed, including porous media combustion, flameless combustion, oxy-fuel combustion, and dual-fuel combustion. The technical challenges and further development needs for efficient LCIG combustion are also discussed.
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Bragança, S. R., A. Jablonski, and J. L. Castellan. "Desulfurization kinetics of coal combustion gases." Brazilian Journal of Chemical Engineering 20, no. 2 (June 2003): 161–69. http://dx.doi.org/10.1590/s0104-66322003000200010.
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Scott, S. K. "Combustion, flame and explosion of gases." Fuel 67, no. 3 (March 1988): 444–45. http://dx.doi.org/10.1016/0016-2361(88)90335-3.
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Spalding, D. B. "Combustion flames and explosions of gases." International Journal of Heat and Mass Transfer 31, no. 1 (January 1988): 211. http://dx.doi.org/10.1016/0017-9310(88)90240-2.
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Shih, Teng-Shih, Chian-Bound Chung, and Kwo-Zong Chong. "Combustion of AZ61A under different gases." Materials Chemistry and Physics 74, no. 1 (February 2002): 66–73. http://dx.doi.org/10.1016/s0254-0584(01)00412-6.
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Kuznetsov, V. R. "Turbulent combustion of partially mixed gases." Combustion, Explosion, and Shock Waves 22, no. 5 (1987): 525–30. http://dx.doi.org/10.1007/bf00755519.
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Gray, Peter. "Combustion, flames & explosions of gases." Combustion and Flame 73, no. 1 (July 1988): 107–8. http://dx.doi.org/10.1016/0010-2180(88)90057-0.
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Hwang, D., Y. Song, and K. Ahn. "Combustion instability characteristics in a dump combustor using different hydrocarbon fuels." Aeronautical Journal 123, no. 1263 (April 30, 2019): 586–99. http://dx.doi.org/10.1017/aer.2019.19.
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ABSTRACTThe combustion instability characteristics in a model dump combustor with an exhaust nozzle were experimentally investigated. The first objective was to understand the effects of operating conditions and geometric conditions on combustion instability. The second objective was to examine more generalised parameters that affect the onset of combustion instability. Three different premixed gases consisting of air and hydrocarbon fuels (C2H4, C2H6, C3H8) were burnt in the dump combustor at various inlet velocity, equivalence ratio and combustion chamber length. Dynamic pressure transducer and photomultiplier tube with a bandpass filter were used to measure pressure fluctuation and CH* chemiluminescence data. Peak frequencies and their maximum power spectral densities of pressure fluctuations at same equivalence ratios showed different trends for each fuel. However, the dynamic combustion characteristics of pressure fluctuations displayed consistent results under similar characteristics chemistry times regardless of the used hydrocarbon fuels. The results showed that characteristic chemistry time and characteristic convection time influenced combustion instabilities. It was found that the convective-acoustic combustion instability could be prevented by increasing the characteristic chemistry time and characteristic convection time.
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Berdnikov, A. A. "Processes occurring in an engine with an unconventional duty cycle." Izvestiya MGTU MAMI 11, no. 2 (June 15, 2017): 2–7. http://dx.doi.org/10.17816/2074-0530-66874.
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An internal combustion engine is a thermal machine that converts thermal energy into mechanical energy. Currently, the existing engines operate in cycles of Otto, Diesel and Sabate-Trinkler. Such cycles are usually called traditional. As is known, traditional internal combustion engines do not have a high coefficient of efficiency due to large losses of heat with exhaust gases, heat removal to the cooling system, etc. The reserves of increasing the efficiency are very high. However, modern engine building has reached a high level and further improvement of the working process in traditional cycles is already ineffective. The article proposes a non-traditional seven-stroke internal combustion engine and examines the processes occurring in the cylinders of such an engine. In the main cylinder of the engine, the working cycle proceeds as in a traditional four-stroke internal combustion engine: at the first stroke, there is an intake, on the second stroke - compression, on the third - combustion and operating stroke, but in the fourth cycle the exhaust gases are not diverted from the cylinder, but are sent to an additional cylinder - there is a continued expansion of gases (operating stroke). At the fifth bar, the exhaust gases are compressed in an additional cylinder, and water is supplied at the end of the compression. Selecting heat from the heated parts of the cylinder-piston group and compressed gases, the water evaporates, and the expanding steam performs useful work (the sixth stroke is the operating stroke). At the seventh stroke, the piston moves to the top dead center, displacing the steam with the exhaust gases. Preliminary calculations showed that the maximum pressure of the seven-cycle operating cycle of the internal combustion engine can reach up to 20 MPa, this increases the power and fuel economy of the engine. The injection of water somewhat reduces the maximum cycle temperature and the toxicity of the exhaust gases. Such advantages give reason for the implementation of the working cycle of the internal combustion engine in a seven-cycle scheme.
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Srinivasan, Raj A., Suresh Sriramulu, Sivakumar Kulasekaran, and Pradeep K. Agarwal. "Mathematical modeling of fluidized bed combustion — 2: combustion of gases." Fuel 77, no. 9-10 (July 1998): 1033–49. http://dx.doi.org/10.1016/s0016-2361(97)00269-x.
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Bică, Marin, Andrei Stoian, Dragoş Tutunea, and Mădălina Călbureanu. "Reduce deposits on heat exchange surfaces when burning inferior coal." E3S Web of Conferences 112 (2019): 01003. http://dx.doi.org/10.1051/e3sconf/201911201003.
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The phenomenon of soiling of heat exchange surfaces occurs in all types of combustion plants. The deposit of solids (combustion gases particles) worsens heat transfer by reducing combustion efficiency, increasing fuel consumption and pollution. Deposits are influenced by combustion temperature, gas flow rate, dimensions of solids drift by combustion gases as well as the composition of fuel mixtures used (eg inferior coal with flame retardant gas or tar fuel). In the present paper are presented techniques and methods adopted for the reduction of soiling of the heat exchange surfaces and the results obtained on high energy power plants (steam boilers).
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Kuropyatnyk, O. A., and S. V. Sagin. "ENSURING EFFICIENCY AND ENVIRONMENTAL OF MARINE DIESEL ENGINES WHICH USING EXHAUST GAS BYPASS SYSTEM." SHIP POWER PLANTS 43, no. 1 (September 7, 2021): 25–40. http://dx.doi.org/10.31653/smf343.2021.25-40.
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The mechanism of formation toxic components in exhaust gases during oxidation and combustion of fuel in marine internal combustion engines is considered. The system of ship engine by-pass exhaust gases 6L20 Wartsila has been observed. Upon experimental results it has been stated that the by-pass exhaust gases usage favor the ecological parameters of ships engine operation modes – by this at the range of exploitation load 0.55 … 0.85 % from nominal power the nitrogen oxide concentration in exhaust gases is decreased on 1.32 ... 12.97 %, but the specific effective fuel oil consumption is increasing to 4.13 %.
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Aguilar Vizcarra, Duilio, Doris Esenarro, and Ciro Rodriguez. "Design of a Pyroacuotubular (Mixed) Boiler for the Reduction of Flue Gas Emissions through the Simultaneous Generation of Hot Water and Water Steam." Fluids 7, no. 9 (September 18, 2022): 312. http://dx.doi.org/10.3390/fluids7090312.
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Environmental protection is a continuous challenge that requires innovating the combustion process of boilers that emit polluting gases. This research proposes a novel pyroacuotubular (mixed) boiler design that reduces the emission of combustion gases by hot water and steam. The applied methodology considers the dimensioning-construction, modification, and analytical calculation of water volume, metallic masses, heat for hot water and steam generation, and combustion gases. The Ganapaty method of heat transfer is applied to prioritize the velocity of gas displacement, the pressure drop along the pipe, and its application on surfaces. In the parallel generation of hot water and steam, a mass of CO2 (1782.72 kg/h) and CO (5.48 kg/h) was obtained; these masses were compared with the results of the proposed design, obtaining a reduction in the mass of gases emitted to the environment in hot water CO2 (44.35%) and CO (44.27%); steam CO2 (55.65%) and CO (55.66%). A significant reduction was achieved in the simultaneous generation of hot water and steam compared to the individual generation, which shows that the simultaneous generation of the pyroacuotubular (mixed) boiler reduces the emission of combustion gases.
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Liu, Aiguo, Ruiyang Fan, Qiaochu Liu, Lei Xi, and Wen Zeng. "Numerical and Experimental Study on Combustion Characteristics of Micro-Gas Turbine Biogas Combustor." Energies 15, no. 21 (November 7, 2022): 8302. http://dx.doi.org/10.3390/en15218302.
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The use of biogas in land-based gas turbines for power generation is a promising approach to reducing greenhouse gases and our dependence on fossil fuels. The focus of this research was to investigate the fuel/air mixing and combustion performance in an DLE (dry low emission) type can combustor designed for a micro-gas turbine. The fuel and air mixing uniformity was studied considering the air flow characteristic and fuel injection performance through the numerical simulation. The influence of the fuel/air mixing characteristics on the combustion characteristics was studied by numerical simulation and experimental tests. The combustion characteristics studied included the temperature field in the combustor, the pattern factor at the combustor outlet, combustion efficiency, and pollutant emission characteristics. The results show the position of the fuel nozzle has little effect on the mixing uniformity due to the limited mixing space for the micro-gas turbine combustor, while there are optimal fuel nozzle diameters to generate the suitable fuel jet momentum for the mixing process. The fuel/air mixing characteristics had an obvious influence on the combustion performance for the studied DLE combustor. The increase in the fuel air mixing uniformity can decrease the NOx emissions and generate a better temperature distribution at the combustor outlet. The increased mixing uniformity may decrease the combustion efficiency and increase the CO emissions of the micro-gas turbine combustor.
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Portola, Vyacheslav, Alyona Bobrovnikova, Georgii Shirokolobov, and Dmitiy Paleev. "Detection and location of places of spontaneous combustion of coal in mines due to gas anomalies on the earth’s surface." E3S Web of Conferences 174 (2020): 01061. http://dx.doi.org/10.1051/e3sconf/202017401061.
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The effectiveness of localization and extinguishing of places of underground fires that occur in mine worked out spaces depends on information about the location of a place of spontaneous combustion. Existing methods to detect the processes of coal spontaneous combustion in mines include monitoring the content of gases in mine atmosphere, released during the spontaneous combustion of coal. However, this control method does not allow determining the location of a place of combustion, since the paths of gas movement in the worked out space are unknown. The surface gas survey allows to determine the location of the underground fire. The calculations showed that gases, generated in the fire seat, spread to the earth’s surface due to molecular diffusion, the thermal depression developed by the fire seat and the drops of air pressure created by the ventilation fans. The dependences of the distribution of fire gases content in rocks on the rate of drops of air pressure between the worked out space in a mine with a fire seat and the atmosphere on the surface of the earth are obtained. Mine researches have confirmed the formation of anomalies of fire gases in rocks and soil over places of spontaneous combustion of coal occurred in worked out space. When conducting a gas survey, it is sufficient to measure the content of fire gases in the soil at a depth of 0.5-1.0 m.
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Kozdrach, Rafal, and Andrzej Stepien. "The Evaluation of Quality of the Co-Firing Process of Glycerine Fraction with Coal in the High Power Boiler." C 8, no. 2 (May 12, 2022): 28. http://dx.doi.org/10.3390/c8020028.
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The article presents the test results of the co-firing process of a glycerine fraction derived from the production of liquid biofuels (fatty acid methyl esters) with coal. The test was performed in industrial conditions using a steam boiler with a capacity of approx. 2 MW in one of the building materials manufacturing facilities. The process of co-firing a mixture of a 3% glycerine fraction and eco-pea coal was evaluated. The reference fuel was eco-pea coal. The combustion process, composition and temperature of exhaust gases were analyzed. Incorrect combustion of glycerine fraction may result in the emission of toxic, mutagenic, and carcinogenic substances, including polycyclic aromatic hydrocarbons. During the test of the combustion process of a mixture of glycerine fraction and eco-pea coal, a decrease in the content of O2, CO, and NOx was observed as well as an increase in the content of H2, CO2, and SO2 in the fumes and growth of temperature of exhaust gases in relation to the results of combustion to eco-pea coal. Reduced content of carbon monoxide in exhaust gases produced in the combustion could be caused by the high temperature of the grate or by an excessive amount of oxygen in the grate. The higher content of oxygen in glycerine changes the value of excess air coefficient and the combustion process is more effective. The bigger content of sulfur dioxide in burnt fuels containing the glycerine fraction could be caused by the presence of reactive ingredients contained in the glycerine fraction. The reduced content of nitrogen oxides in exhaust gases originating from the combustion of a fuel mixture containing a fraction of glycerine could be caused by lower content of nitrogen in the glycerine fraction submitted to co-firing with coal and also higher combustion temperature and amount of air in the combustion chamber. The increased content of carbon dioxide in exhaust gases originating from the combustion of fuel mixture containing glycerine fraction could be caused by the influence of glycerine on the combustion process. The increase of hydrogen in the glycerine fraction causes the flame temperature to grow and makes the combustion process more efficient.
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Wresta, Arini, and Aep Saepudin. "Analysis of Product and Temperature of Biogas Combustion in Various Air Biogas Equivalence Ratio and Methane Content." Indonesian Journal of Chemistry 18, no. 2 (May 30, 2018): 211. http://dx.doi.org/10.22146/ijc.23923.
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Biogas resulted from anaerobic digestion of organic compounds have various methane content depend on the type of the degraded material. The methane content of biogas is range between 40–80% that influence the heating value and combustion characteristic of that biogas. The higher methane content can be obtained through upgrading biogas by removing CO2 and other trace components like H2S, NH3, and water vapor. This research was a simulation of product composition and temperature of biogas combustion in various methane content and air biogas equivalence ratio. Biogas combustion was done in combustion chamber at constant pressure of 1 atm. Biogas and air enter into combustion chamber at temperature approximately of 30 °C as the common ambient temperature in Indonesia. The input air was designed higher than stoichiometric need in order to reach complete combustion. Combustion reaction between methane and O2 then carried out in the combustion chamber to produce CO2 and H2O. The product gases consisting of CO2, H2O, N2, and excess O2, bring heat from combustion reaction and exit from combustion chamber at the higher temperature. The analysis was done for methane content range between 20 and 100% with air biogas equivalence ratio from 1 until 3. The simulation result showed that for V m3 biogas, the combustion gases could reach 0.12271 until 1.26798V gmol with temperature above 700 °C until above 1900 °C. More than 50% component in the combustion gases is N2 as inert material from input air to combustion chamber.
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Fąfara, Jean-Marc, and Norbert Modliński. "Computational Fluid Dynamics (CFD) Assessment of the Internal Flue Gases Recirculation (IFGR) Applied to Gas Microturbine in the Context of More Hydrogen-Enriched Fuel Use." Energies 16, no. 18 (September 19, 2023): 6703. http://dx.doi.org/10.3390/en16186703.
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Renewable energy is a promising substitute for fossil fuels when corelated with P2G technology. To optimise P2G efficiency, there is a need to increase hydrogen fraction in the fuel stream. Simultaneously gas microturbines are widely applied in many industry sectors. These devices are often equipped with diffusion combustors. This situation was investigated in this paper. The P2G and gas microturbines may be integrated together in the future leading to the application of hydrogen-enriched fuel. Hydrogen-enriched fuel causes increase in combustion temperature and velocity. In a nonadapted combustor, these phenomena could result in an increase of NOx emissions and risk of material overheating and failure. In order to adapt the combustors for hydrogen-enriched fuel, the concept of autonomous internal flue gases recirculation (IFGR) system was applied to this issue. In this paper, the IFGR system applied to gas microturbine was studied in terms of hydrogen-enriched fuel application. The obtained exhaust gases recirculation ratios were too low to affect the combustion process as it was expected. The observed combustion modifications in the combustor were hardly linked to the air flow modification in the liner, due to IFGR system implementation. After CFD studies, the proposed IFGR system does not seem to provide the expected effects.
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Faitar, Catalin, Feiza Memet, and Nicolae Buzbuchi. "A Numerical Analysis of the Combustion and the Study of the Exhaust Gases Resulting therefrom in the Marine Engines." Revista de Chimie 70, no. 3 (April 15, 2019): 929–33. http://dx.doi.org/10.37358/rc.19.3.7033.
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Maritime University of Constanta, Faculty of Naval Electromechanics, 104 Mircea cel Batran Str., 900663, Constanta, Romania Combustion inside diesel engine cylinders is the critical factor that controls the emission and combustion gases. Fuel injection in the engine cylinder is the decisive factor in the combustion of diesel engines and, consequently, combustion can be effectively controlled if the fuel injection process is efficiently controlled. From this perspective, the simulation of the complex processes of fuel injection in diesel engines in various situations can make a positive contribution to the optimization of marine propulsion systems. Also, correct dimensioning of the injection system components and its optimization and, implicitly, the combustion parameters, can have positive results in the context of reducing the impact of combustion gases of internal combustion engines, on the greenhouse effect and global warming.
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Paradiz, Bostjan, Panagiota Dilara, Gunther Umlauf, Ivan Bajsic, and Vincenc Butala. "Dioxin emissions from coal combustion in domestic stove: Formation in the chimney and coal chlorine content influence." Thermal Science 19, no. 1 (2015): 295–304. http://dx.doi.org/10.2298/tsci140113079p.
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Combustion experiments conducted in domestic stove burning hard coal demonstrated a predominant influence of the coal chlorine content on the PCDD/F emissions, together with a pronounced effect of the flue gas temperature. PCDD/F concentrations of over 100 ng TEQ/m3, three orders of magnitude higher than in a modern waste incinerator, were measured in the flue gases of a domestic stove when combusting high chlorine coal (0.31 %). The PCDD/F concentrations in the flue gases dropped below 0,5 ng TEQ/m3, when low chlorine coal (0.07 %) was used. When low chlorine coal was impregnated with NaCl to obtain 0.38 % chlorine content, the emission of the PCDD/Fs increased by two orders of magnitude. Pronounced nonlinearity of the PCDD/F concentrations related to chlorine content in the coal was observed. The combustion of the high chlorine coal yielded PCDD/F concentrations in flue gases one order of magnitude lower in a fan cooled chimney when compared to an insulated one, thus indicating formation in the chimney. The influence of flue gas temperature on the PCDD/F emissions was less pronounced when burning low chlorine coal. The predominant pathway of the PCDD/F emissions is via flue gases, 99 % of the TEQ in the case of the high chlorine coal for insulated chimney.
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Kovalev, I. V., V. V. Losev, M. V. Saramud, D. I. Kovalev, and A. S. Lifar. "A promising approach to assessing anthropogenic impact on natural ecosystems for the sustainable functioning of cyber-physical systems." IOP Conference Series: Earth and Environmental Science 981, no. 3 (February 1, 2022): 032072. http://dx.doi.org/10.1088/1755-1315/981/3/032072.
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Abstract The article deals with the problem of controlling the emission of gases and suspended particles of thermal power plants. It is a closed system with mutual influence of physical processes (fuel preparation, fuel combustion, flue gases and particulate matter removal) on computational processes (fuel quality control, fuel combustion completeness control, control of permissible emissions into the atmosphere) and the reverse influence of computational processes on physical ones (fuel preparation modes change, fuel combustion modes change, flue gases and suspended particles removal modes change). The fault tolerance and predictability improvement of such a cyber-physical system is associated with an increase of the data reliability from existing feedback loops and the multimodality of physical process control systems.
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Liu, C. H., R. M. Perez-Ortiz, and J. H. Whitelaw. "Vaporizer Performance." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 206, no. 4 (July 1992): 265–73. http://dx.doi.org/10.1243/pime_proc_1992_206_126_02.
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Measured values of fuel droplet velocity, size and flux are presented for a vaporizer based on a T-shaped duct with upstream atomization by a single axial jet and by six radial jets. They were obtained for a practical range of kerosene and air flowrates and inlet air temperatures with the vaporizer in free air and in a sector of an annular combustor with combustion. Phase Doppler velocimetry was used to measure droplet velocity and size distributions and was complemented by photographic visualization of the flames within the combustor. The results obtained outside the combustor, and without combustion, showed that the Sauter mean diameter of the droplets ranged from 20 to 60 μm and the liquid-fuel flux from 0.2 to 30 per cent of the total fuel as the inlet air temperature was increased from that of ground-idle to that of full power. The droplet size and liquid-fuel flux also diminished with an increase in air flowrate, and an arrangement of six radial jets resulted in better atomization than an axial arrangement. The corresponding fluxes with combustion were in the range between 0.1 and 8 per cent as a consequence of heat transfer from combusting gases to the vaporizer tubes. Experience with the vaporizer operating within the combustor at fuel flowrates and inlet air temperatures representative of take-off showed that the vaporizer performance could deteriorate rapidly due to the formation of carbon deposits, particularly in the region where the flow impinged on the cross tube. The deposits led to reduced heat transfer and vaporization with a consequently larger proportion of larger droplets and a tendency for the region of intense combustion to move downstream.
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Herrera, Bernardo, Juan Rivas, Jorge Muñoz, and Karen Cacua. "Effect of the combustion system on reduction of thermal specific energy consumption in an industrial high temperature process." DYNA 88, no. 217 (May 24, 2021): 273–81. http://dx.doi.org/10.15446/dyna.v88n217.93030.
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This paper presents an experimental study carried out in an industrial furnace for frits production using different configurations of burners based on different combustion techniques such as enriched air combustion, flat-flame oxy-combustion and preheater air combustion. The residence time of combustion gases inside the furnace also was modified. Several combustion configurations were tested and its effects on productivity and thermal energy specific consumption and efficiency were determined. The results show that higher residence time of the combustion gases can decrease significantly the specific consumption of fuel, while the change of the burners and combustion techniques did not show significant effects on decreasing the energy consumption. However, it is highlighted that the oxy-combustion flat-flame burners produced the lowest specific consumption of fuel. Even though the experiments were conducted in a furnace for frit production, the corresponding results can also be applied to guide or improve other industrial high temperature processes.
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Churakov, A. V., P. N. ,. Shushkov, I. S. Dolzhikov, and L. M. Mikhailova. "The use of digital twin technology in the testing laboratories of forest machines." Bezopasnost i okhrana truda v lesozagotovitelnom i derevoobrabatyvayuschem proizvodstvakh (Occupational Health and Safety in Logging and Woodworking Industries), no. 6 (November 17, 2023): 19–26. http://dx.doi.org/10.33920/pro-05-2306-03.
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One of the important environmental problems is the damage caused to the environment by the exhaust gases of internal combustion engines. They contain both non-toxic (nitrogen, carbon dioxide) and toxic (carbon monoxide, hydrocarbons, aldehydes, benzapyrene) chemicals that have a negative impact on both humans and nature. In addition to the daily operation of logging equipment, exhaust gases also occur during laboratory tests of internal combustion engines. In order to minimize the amount of exhaust gases during the study and testing of internal combustion engines of forest transport, the article proposes a variant of a digital twin, where by means of several tests of this sample, it will be possible to simulate other possible options, but with its electronic copy.
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Hutchins, T. E., and M. Metghalchi. "Energy and Exergy Analyses of the Pulse Detonation Engine." Journal of Engineering for Gas Turbines and Power 125, no. 4 (October 1, 2003): 1075–80. http://dx.doi.org/10.1115/1.1610015.
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Energy and exergy analyses have been performed on a pulse detonation engine. A pulse detonation engine is a promising new engine, which uses a detonation wave instead of a deflagration wave for the combustion process. The high-speed supersonic combustion wave reduces overall combustion duration resulting in an nearly constant volume energy release process compared to the constant pressure process of gas turbine engines. Gas mixture in a pulse detonation engine has been modeled to execute the Humphrey cycle. The cycle includes four processes: isentropic compression, constant volume combustion, isentropic expansion, and isobaric compression. Working fluid is a fuel-air mixture for unburned gases and products of combustion for burned gases. Different fuels such as methane and JP10 have been used. It is assumed that burned gases are in chemical equilibrium states. Both thermal efficiency and effectiveness (exergetic efficiency) have been calculated for the pulse detonation engine and simple gas turbine engine. Comparison shows that for the same pressure ratio pulse detonation engine has better efficiency and effectiveness than the gas turbine system.
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Tsuchiya, Yoshio. "Chemical Modeling of Fire Gases." Journal of Fire Sciences 13, no. 3 (May 1995): 214–23. http://dx.doi.org/10.1177/073490419501300304.
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When a fuel containing C, H, and O burns, CO2 and H2O are the major combustion products and, depending on the conditions, CO, unburnt gasified fuel, and other products of incomplete combustion are produced. In this paper, chemical modeling to calculate rates of generation and mass fractions of various products in reference to the fuel/O2 equivalence ratio is presented. In addition to chemical balances, empirical CO/CO 2 ratios are used. CO is con sidered to be the most significant factor for toxicity hazard assessment in build ing fires. This modeling provides generation rates and mass fractions of CO among other species of gases. This model can be used as a sub-model in fire models for estimating CO.