scholarly journals Simulation gas combustion process in modern heat generators of small and medium power

2020 ◽  
Vol 972 ◽  
pp. 012073
Author(s):  
M Valeev ◽  
A Dyudina ◽  
A A Fatikhov ◽  
M Ziganshin
Keyword(s):  
Combustion Process ◽  
Gas Combustion

SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

scholarly journals Jet A and Propane gas combustion in a turboshaft engine: performance and emissions reductions

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Ali Hasan ◽  
Oskar J. Haidn
Keyword(s):  
Combustion Process ◽  
Engine Performance ◽  
Emissions Reductions ◽  
Gas Combustion ◽  
Liquid Petroleum Gas ◽  
Performance And Emissions ◽  
Air Mixing ◽  
Turboshaft Engine ◽  
Engine Performance And Emissions ◽  
Lower Carbon

AbstractThe Paris Agreement has highlighted the need in reducing carbon emissions. Attempts in using lower carbon fuels such as Propane gas have seen limited success, mainly due to liquid petroleum gas tanks structural/size limitations. A compromised solution is presented, by combusting Jet A fuel with a small fraction of Propane gas. Propane gas with its relatively faster overall igniting time, expedites the combustion process. Computational fluid dynamics software was used to demonstrate this solution, with results validated against physical engine data. Jet A fuel was combusted with different Propane gas dosing fractions. Results demonstrated that depending on specific propane gas dosing fractions emission reductions in ppm are; NOx from 84 to 41, CO2 from less than 18,372 to less than 15,865, escaping unburned fuels dropped from 11.4 (just Jet A) to 6.26e-2 (with a 0.2 fraction of Propane gas). Soot and CO increased, this is due to current combustion chamber air mixing design.

Comparative Evaluation of Combustion Codes for Low-Btu Gas Applications

1991 ◽  
Author(s):  
Tah-Teh Yang ◽  
Ajay K. Agrawal
Keyword(s):  
Structural Integrity ◽  
Combustion Process ◽  
Computer Code ◽  
Physical Models ◽  
Gas Combustion ◽  
Combustion Modeling ◽  
Coal Gas ◽  
Combustion Models ◽  
Efficient Combustion ◽  
User Friendly

Four computer codes (PHOENICS, PCGC, FLUENT and INTERN) representing a spectrum of existing combustion modeling capabilities were evaluated for low-Btu gas applications. In particular, the objective was to identify computer code(s) that can be used effectively for predictions of (a) the flow field to yield efficient combustion, (b) the temperature field to ensure structural integrity and (c) species concentrations to meet environmental emission standards in a gas turbine combustor operating on low-Btu coal gas. Detailed information on physical models, assumptions, limitations and operational features of various codes was obtained through a series of computational runs of increasing complexity and grouped as (a) experimental validation, (b) code comparison and (c) application to coal gas combustion. INTERN is not suitable for the present application since it has been tailored to model combustion process of premixed hydrocarbon fuels. FLUENT is easy to use and has detailed combustion models (in Version 3), however, it is not favored here because the user is unable to alter, modify or change the existing model(s). While PCGC-2 has the most comprehensive models for combustion, it is not user friendly and is inherently limited to axisymmetric geometry. PCGC-3 is expected to overcome these drawbacks. Built in combustion models in PHOENICS are similar to those in FLUENT. However, the user can implement advanced models on PHOENICS leading to a flexible and powerful combustion code.

Numerical Simulation of Natural Gas Combustion Process Using a One-Step and a Two-Step Reaction

2002 ◽  
Author(s):  
Angela O. Nieckele ◽  
Moˆnica F. Naccache ◽  
Marcos S. P. Gomes ◽  
Joa˜o N. E. Carneiro ◽  
Andre´ Augusto Isnard ◽  
...  
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Process ◽  
Chemical Species ◽  
Reaction Model ◽  
Gas Combustion ◽  
First Case ◽  
Natural Gas Combustion ◽  
Cylindrical Furnace ◽  
Global Reaction

The work evaluates the combustion of natural gas in a cylindrical furnace. The Generalized Finite Rate Reaction Model was selected for predicting the reactions. Two situations were considered. In the first case the combustion of the fuel was predicted by a single global reaction, and in the second case a two-step reaction was considered for predicting the combustion process. The conservation equations of mass, momentum, energy and chemical species were solved by the finite volume procedure, with the commercial software FLUENT. The turbulent flow was modeled by employing the two differential equation κ–ε model. The solutions obtained with the two reaction models, for the temperature and species concentration fields, were compared among them and against experimental data available in the literature. It was observed that the two-step reaction model represents better the physical phenomena, showing a better agreement with the experimental data.

scholarly journals Gas Combustion Efficiency Enhancement: Application Study of Intense Elestrostatic Field

2019 ◽  
Vol 56 (4) ◽  
pp. 3-16
Author(s):  
O. Krickis ◽  
N. Zeltins
Keyword(s):  
Electrostatic Field ◽  
Flue Gas ◽  
Combustion Process ◽  
Field Application ◽  
Process Efficiency ◽  
Simultaneous Increase ◽  
Efficiency Enhancement ◽  
Gas Temperature ◽  
Gas Combustion ◽  
The Impact

Abstract A number of international, European Union and Latvian legislative acts have been developed, which regulate the efficiency of gas combustion plants and greenhouse gas emissions in the atmosphere. These legislative acts require the development of new scientifically efficient methods for gas optimal combustion with a minor impact on the environment. In order to achieve such a goal, different methods can be used, but the most efficient is an intensive electrostatic field application to control combustion and harmful emission formation in premixed flames. In the framework of the current study, the authors developed a hybrid burner, which allowed generating an intensive electrostatic field with intensity of more than 1000 kV/m. The study also investigated the impact of such a field on the formation of harmful emissions, including CO2 and flue gas temperature. The empirical results showed that an intensive DC electrostatic field generated inside of the burner had an impact on the flame shape, CO2, NOx emissions and flue gas temperature. In its turn, by applying an intensive pulsating electrostatic field (multivariable experiment) it was possible to achieve the reduction in NOx, CO emissions with a simultaneous increase in flue gas temperature, which was related to combustion process efficiency enhancement.

Low Fuel-NOx Combustion of Synthetic LCV Gas

2006 ◽  
Author(s):  
Belkacem Adouane ◽  
Guus Witteveen ◽  
Wiebren de Jong ◽  
Jos P. van Buijtenen
Keyword(s):  
Gas Turbines ◽  
Research Work ◽  
Combustion Process ◽  
Calorific Value ◽  
Green Energy ◽  
Nox Emissions ◽  
Gas Combustion ◽  
Reduction Of Nox ◽  
Thermal Nox ◽  
Fuel Nox

Fuel NOx is one of the main issues related to the combustion of biomass derived Low Calorific Value (LCV) Gas. The high NOx emissions accompanying the combustion of that fuel in gas turbines or gas engines are compromising the CO2 neutral character of biomass and are a barrier towards the introduction of this green energy source in the market. The reduction of NOx emissions has been one of the main preoccupations of researchers in the LCV gas combustion field. Although, much has been achieved for thermal NOx which is caused mainly by the conversion of the nitrogen of the air in high temperature regions, less work has been devoted to the reduction of fuel NOx, which has as a main source the fuel bound nitrogen FBN, namely ammonia in case of biomass. Reducing the conversion of the FBN to NOx has been the main issue in recent research work. However, fuel NOx could be reduced significantly applying methods; like washing the gas in a scrubber prior its entrance to the combustor, and SNCR or SCR methods applied at the exhaust. But those solutions stay very expensive in terms of polluted waste water and catalyst cost. In this paper, the approach is to reduce the conversion of FBN to NOx inside a newly designed combustor. The idea is to optimize the combustion process ending up with the lowest possible conversion of FBN to NOx. The LCV gas used in the experiments described in this paper is made by mixing CO, CO2, H2, natural gas and N2 with proportions comparable to those of the real LCV gas. This gas is then doped with NH3 to simulate the FBN. In this paper the conversion ratio of FBN to NOx versus the FBN concentration is presented. Furthermore, the system is investigated in terms of the effect of CH4 concentration on the conversion of FBN to NOx. And measurements along the combustor axis were performed with a traversing probe where temperature and important emissions along the axis were measured. In all the experiments described in the paper, The LCV gas has an HHV (High Calorific Value) ranging from 4 to 7Mj/nm3. The newly designed combustor contains an embedded inner cylinder. In these experiments presented are without that embedded cylinder. The purpose of the current experiments is to be compared to the later experiments with the insert in order to define clearly the effect of the inner cylinder. Furthermore, this arrangement, i.e. without the insert, gave us the opportunity to traverse the combustor by a probe and to measure temperature and species profiles, which is of a great importance in defining the key parameter controlling the conversion of NH3 to NOx.

Combustion of pellets produced from the powders of coconut and cashew nut shells: Chemical, thermal and emission analyses

2021 ◽  
pp. 0734242X2098341
Author(s):  
Gilvan R dos Santos ◽  
Allison M de Sousa ◽  
Brenna KS Lima ◽  
Fabriciany L Moreira ◽  
Fladimir L Gondim ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Combustion Process ◽  
Clean Energy ◽  
Exhaust Gas ◽  
Gas Combustion ◽  
Cashew Nut ◽  
Oil Derivatives ◽  
Safety Parameters ◽  
Cashew Nut Shell ◽  
Biomass For Energy

Most of the energy consumed worldwide comes from non-renewable sources, such as oil derivatives, making it necessary to search for renewable, clean energy sources, with emphasis on biomass from agricultural and industrial waste. Coconut shell pellets (CSPs) and cashew nut shell pellets (CNSPs) were manufactured and subsequently subjected to chemical, thermal and exhaust gas analyses of their combustion. Mean temperature results in the combustion area were 366.44 ± 84.79°C (CSPs) and 295.00 ± 89.47°C (CNSPs). The exhaust gas combustion values were 19.43 ± 0.57% (CSPs) and 18.75 ± 0.77% (CNSPs) of O2, 2348 ± 1241 ppm (CSPs) and 2901 ± 499 ppm (CNSPs) of CO, 14.92 ± 5.06 ppm (CSPs) and 39.83 ± 10.91 ppm (CNSPs) of NOx, and 441.25 ± 130.41 ppm (CSPs) and 2841.50 ± 765.26 ppm (CNSPs) of CH4. In conclusion, the combustion process of CSPs proved to be less polluting and more energy efficient when compared with CNSPs. The analyses of the exhaust gases from the combustion of these biomasses can serve as a basis for the creation of safety parameters and public policies to regulate the use of biomass for energy purposes.

scholarly journals Numerical comparative analysis of the combustion process in an engine powered by CNG

2012 ◽  
Vol 148 (1) ◽  
pp. 62-70
Author(s):  
Ryszard MICHAŁOWSKI ◽  
Krzysztof MIKSIEWICZ ◽  
Marcin TKACZYK
Keyword(s):  
Fuel Injection ◽  
Combustion Process ◽  
Qualitative Evaluation ◽  
Fuel Mixture ◽  
Diesel Oil ◽  
Numerical Results ◽  
Combustion Model ◽  
Numerical Application ◽  
Gas Combustion ◽  
Natural Gas Combustion

This paper contains the analysis of Compressible Natural Gas combustion process in engine dedicated to diesel oil. The analysis was performed on the basis of the numerical results of two systems for methane dosing. The first simulation considers the CNG delivery into the suction manifold, and subsequent production of air-fuel mixture as well as separate combustion model of a homogenous mixture. The second simulation comprises a numerical application of the fuel injection directly into the combustion chamber. Therefore it is also a simulation of a combustion process. Among the numerical results conducted with the aid of Computational Fluid Dynamics the following parameters were selected for the combustion qualitative evaluation in terms of mechanical, heat and flow properties: fields of pressure and temperature, mass fraction of the fuel and turbulence intensity. All test were conducted on the engine adopted to be fed with CNG.

scholarly journals Evaluation of the possibility of the sewage sludge gasification gas use as a fuel

2016 ◽  
Vol 23 (2) ◽  
pp. 229-236 ◽  
Author(s):  
Sebastian Werle ◽  
Mariusz Dudziak
Keyword(s):  
Sewage Sludge ◽  
Gas Turbines ◽  
Burning Velocity ◽  
Combustion Process ◽  
Laminar Burning Velocity ◽  
Gas Combustion ◽  
Reducing Atmosphere ◽  
Gasification Process ◽  
Gas Utilization ◽  
Dioxins And Furans

Abstract Biomass is one of the major sources of energy that is estimated to contribute between 10% and 14% of the world’s energy supply. Over the past several years, many societies have established policy targets to increase their production of renewable energy from biomass. The thermo-chemical utilization of biomass includes 4 technologies: the most popular combustion and co-firing, and unconventional: pyrolysis and gasification. Gasification is considered to be the perspective technology because has many advantages in comparison to traditional process of combustion: (1) limited emission of the SO2, NOx, oxides of the heavy metals and no risk of the dioxins and furans emission due to reducing atmosphere in the gasification reactor, (2) volume of the gasification gas is smaller in comparison to flue gases from combustion due to the reducing atmosphere, (3) gasification process produce gas which is potential gaseous fuel in power engineering (engines, gas turbines and boilers) and chemistry. Unfortunately, composition of the gasification gas is always described as a variable. Moreover, it depends on the conditions of the process and quality of the base fuel. For this reason, the use of gasification gas can’t be very easy. For this reason, the knowledge of the basic properties of the gas is very important. Laminar burning velocity is assumed as an important quantity for in the process of the design equipment for the gas utilization. The numerical and experimental results of the laminar burning velocity of sewage sludge gasification gases were presented. Experimental Bunsen burner method was used. Cosilab 3© software for numerical analysis was used. GRI-Mech 3.0 mechanism of gas oxidation was implemented. As a result of the work, the set of the parameters where the sewage sludge gasification gas combustion process is stable with effective heat release, were presented.

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