KESAN SUDUT PUSARAN TERHADAP PEMBAKARAN MENGGUNAKAN PEMUSAR JEJARIAN DWI ALIRAN

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
Muhammad Roslan Rahim ◽  
Mohammad Nazri Mohd Ja’afar
Keyword(s):  
Swirling Flow ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Flame Length ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Flame Stability ◽  
Wide Spread ◽  
Blue Colour ◽  
The One

Development of combustion systems which involves retrofitting or design of new burners, is made to reduce the formation of pollutant emissions. The reduction of this pollutant emission results from the complete mixing of fuel and air during the combustion process. Meanwhile, non-complete mixing of fuel and air during combustion process can cause ignition problem and create problems in terms of flame stability and combustion efficiency. This article describes a study on the effects of swirling flow generated by a double radial swirler on flame characteristics that is related to the emission of NO. The double radial swirlers used in this study have the angles of 30°/40°, 30°/50° and 30°/60°. Diesel is used as a fuel in this study. The results show that all double radial swirlers used have different effects on the flame characteristics and temperature profile. From all these double radial swirlers, the one with an angle of 30°/60° produces flame with high temperature, short flame length with blue colour and wide spread.

Effect of Flame Angle Using Various Swirler Angle in Combustion Performance

2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Muhammad Roslan Rahim ◽  
Mohammad Nazri Mohd Jaafar
Keyword(s):  
Fossil Fuels ◽  
Swirling Flow ◽  
Combustion Process ◽  
Flame Length ◽  
Oxides Of Nitrogen ◽  
Photochemical Smog ◽  
No Emission ◽  
Blue Colour ◽  
The One ◽  
Short Time

The abbreviation N  is commonly used as a reference to all oxides of nitrogen and the examples of oxides of nitrogen are NO, N  and O. These emission gases mostly come from the combustions of fossil fuels and biofuels in industrial activities and also in road traffics globally. N  as a pollutant deserves special attention because of its various issues on human’s health and environment. Some of these issues are global warming, acid rain, ozone layer depletion and photochemical smog. To address these issues, some studies are concentrating on the reduction of NO emission from the combustion process. This paper describes a study in the effects of swirling flow generated by using a radial swirler on flame characteristics that is related to the emission of NO. The radial swirlers used in this study have the angles of 40°, 50° and 60°. Diesel is used as a fuel in this study. The results show that all radial swirlers used have different effects on the flame characteristics. From all these radial swirlers, the one with an angle of 60° produces flame with high temperature, short flame length with blue colour and wide spread. The results also show a short time residence during combustion process that could reduce the formation of CO and N . 

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

Effects of Firing Mode on the Performance of Flameless Combustion: A Review Paper

2013 ◽  
Vol 388 ◽  
pp. 206-212
Author(s):  
Ali Abuelnuor Abdeen Abuelnuor ◽  
Mazlan Abdul Wahid ◽  
Aminuddin Saat ◽  
Mohsin M. Sies ◽  
Mohamed Osman Abdalla ◽  
...  
Keyword(s):  
Energy Savings ◽  
High Efficiency ◽  
Review Paper ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Flameless Combustion ◽  
Auto Ignition ◽  
Firing Mode ◽  
Industrial Heating

Flameless combustion is of a great interest since it simultaneously provides higher thermal efficiency together with controlling the pollutant emission such as NOX. This technology has been used to provide large energy savings in power system and industrial heating applications. In this technology, the preheat temperature of the combustion air must be higher than the auto-ignition temperature of the reactant mixture. In this review, papers concern the effect of firing mode to reduce pollutant emissions such as NOX emission and combustion efficiency for flameless combustion were reviewed. Summaries on the influences of the firing mode in the flameless combustion were presented, discussed and analyzed. The review concludes that all the previous studies have asserted that a parallel firing mode gives much lower pollutant emissions and high efficiency compared with staggered and counter modes.

Lean Low NOx Primary Zones Using Radial Swirlers

1988 ◽  
Author(s):  
H. S. Alkabie ◽  
G. E. Andrews ◽  
N. T. Ahmad
Keyword(s):  
Natural Gas ◽  
Recirculation Zone ◽  
Fuel Injection ◽  
Swirling Flow ◽  
Combustion Efficiency ◽  
Flame Stability ◽  
Nox Emissions ◽  
Primary Zone ◽  
Outer Expansion ◽  
Curved Blade

Swirling flow primary zones with between 30% and 60% simulated primary zone air flow were investigated using curved blade radial swirlers. Two radial swirlers were compared with the same open area but different outlet diameters, d, giving different expansion ratios, D/d, from the swirler to the combustor diameter, D. Two combustors were used, 76 mm and 140 mm diameter, the larger one corresponding to the size of several gas turbine can combustors. There was no influence of D/d on the weak extinction. It was demonstrated that an adequate efficiency was not achieved in the weak region until there was a significant outer expansion and associated recirculation zone. It was shown that these systems with central gaseous fuel injection had good flame stability with very low NOx emissions. Propane and natural gas were compared and the NOx emissions were 50% lower with natural gas. The optimum NOx emissions, compatible with a high combustion efficiency, were close to 10 ppm NOx emissions corrected to 15% oxygen.

scholarly journals Pollutant Emissions and Combustion Efficiency Assessment of Engines Using Biodiesel

2020 ◽  
Vol 10 (23) ◽  
pp. 8646
Author(s):  
Juan Carlos Paredes Rojas ◽  
Christopher Rene Torres San Miguel ◽  
Rubén Vázquez Medina ◽  
José Alfredo Leal Naranjo ◽  
Fernando Elí Ortiz Hernàndez ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Diesel Engine ◽  
Analytical Study ◽  
Combustion Process ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Technical Problems ◽  
Biodiesel Blends ◽  
Electric Generator ◽  
Efficiency Assessment

This paper evaluates the biodiesel produced by a biodiesel plant located in the Mexican Centre for Cleaner Production (CMP + L by its acronym in Spanish) of the National Polytechnic Institute of Mexico. Pollutant emissions from two types of engines were studied: a low power monocylinder engine and a 30-kW electric generator diesel engine. The tests were performed with the following blends: B5, B10, B15, B20, B30, B40, and B50. Parameters such as carbon monoxide, nitrogen oxide, hydrocarbons, and combustion efficiency were analyzed, as well as sulfur dioxide, oxygen, and combustion temperatures. It was demonstrated that NOx increases as the percentage of biodiesel increases, while CO decreases slightly using the monocylinder engine. In the case of the electric generator diesel engine, the B5 mixture had the highest trend for NOx and the lowest trend for CO. Likewise, combustion efficiency was found to be severely affected by the biodiesel blends, i.e., from B5 to B20. An analytical study and experimental thermography tests of the combustion process with biodiesel blends were carried out, and the technical problems of operation when incorporating biodiesel blends are presented.

Computer Simulation of Combustion Process in a Piston Engine With a Porous Medium Regenerator

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Lei Zhou ◽  
Maozhao Xie ◽  
Ming Jia ◽  
Junrui Shi
Keyword(s):  
Porous Medium ◽  
Combustion Process ◽  
Kinetic Mechanism ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Mixture Formation ◽  
Computational Fluid Dynamics Cfd ◽  
Reduce Emissions ◽  
Detailed Kinetic Mechanism ◽  
Reciprocating Movement

In the regenerative engine, effective heat exchange and recurrence between gas and solid can be achieved by the reciprocating movement of a porous medium regenerator in the cylinder, which considerably promotes the fuel-air mixture formation and a homogeneous and stable combustion. A two-dimensional numerical model for the regenerative engine is presented in this study based on a modified version of the engine computational fluid dynamics (CFD) software KIVA-3V. The engine was fueled with methane and a detailed kinetic mechanism was used to describe its oxidation process. The characteristics of combustion and emission of the engine were computed and analyzed under different equivalence ratios and porosities of the regenerator. Comparisons with the prototype engine without the regenerator were conducted. Results show that the regenerative engine has advantages in both combustion efficiency and pollutant emissions over the prototype engine and that using lower equivalence ratios can reduce emissions significantly, while the effect of the porosity is dependent on the equivalence ratio used.

scholarly journals Effects of Swirling Strength of the Premixed Gas Flow on Pollutant Emission in a Heavy-Duty Gas Turbine

2019 ◽  
Vol 118 ◽  
pp. 04038
Author(s):  
Huanhuan Gao ◽  
Zaiguo Fu ◽  
Zhuoxiong Zeng ◽  
Jiang Liu ◽  
Peifen Weng
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Flow ◽  
Swirling Flow ◽  
Combustion Process ◽  
Side Wall ◽  
Pollutant Emission ◽  
Heavy Duty ◽  
Average Mass ◽  
Heavy Duty Gas Turbine

The combustion process and pollutant emission of an annular combustion chamber for a heavy-duty gas turbine were investigated by numerical method. The realizable k-ε model and finite rate/eddy dissipation model were adopted for calculations of turbulence and combustion. The effects of different swirling numbers of the double-swirler inlet on the temperature distribution and the thermal NOx formation in the combustion chamber were analyzed. The results show that the change of the swirling number of the outer swirling flow has a greater influence on the generation of the thermal NOx when compared with that of the inner swirling flow. The maximum average temperature of the central cross section of the combustor does not exceed 1760K. The average mass fraction of the generated thermal NOx at the exit decreases with the increasing outer swirling number. When the outer swirling number is less than 0.8, the generation of the thermal NOx is severe at the side wall of the combustion chamber.

scholarly journals TWO-DIMENSIONAL FLAME INSTABILITY AND CONTROL OF BURNING IN THE HAlF-OPEN FIRECHAMBER

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
V. E. Volkov
Keyword(s):  
Combustion Process ◽  
Open Channels ◽  
Flame Stability ◽  
Front Wall ◽  
Two Dimensional ◽  
One Dimensional ◽  
Fuel Supply ◽  
Flame Instability ◽  
The One ◽  
And Control

The flame stability with regard to two-dimensional exponential perturbations both for the combustion in the half-open fire-chamber and the flame propagating in half-open channels is investigated. It is proved that only instability ispossible for the combustion process. At the same time the one-dimensional flame instability is guaranteed near the front wall of the fire-chamber where the fuel supply is realized. Possibilities for the control of combustion in the halfopenfire-chamber and diminishing of intensity of pulsations are discussed.

scholarly journals Influence of Molding Technology on Thermal Efficiencies and Pollutant Emissions from Household Solid Fuel Combustion during Cooking Activities in Chinese Rural Areas

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2223
Author(s):  
Juan Qi ◽  
Jianjun Wu ◽  
Lei Zhang
Keyword(s):  
Wheat Straw ◽  
Rice Straw ◽  
Solid Fuel ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Molding Pressure ◽  
Process Conditions ◽  
Ignition Point ◽  
Maize Straw

Resident combustion of solid fuel has been widely acknowledged as a high potential for pollutant reduction. However, there is a marked asymmetry between more pollutant emission and less burned volatiles of biomass and coal in the combustion process. To study the solid fuel optimum combustion form in a household stove, both the pollution reduction and energy efficient utilization of crop straws and coals were investigated. Taking the molding pressure and clay addition ratio as variable process conditions, the research of bio-coal briquette (made from the mixture of anthracite and biomass) was implemented in the range of 15~35 MP and 5~15%, respectively. Biomass and coal work complementarily for each other’s combustion property development. In particular, the pyrolysis gas produced by biomass low-temperature devolatilization is featured with low ignition point and is distributed in the bio-coal briquette. Its own combustion provides energy for anthracite particle combustion. Consequently, a positive effect was identified when bio-coal briquettes were used as residential fuel, and further improvement manifested in reducing more than 90% of particle matter (PM) and achieving about twice the thermal efficiencies (TEs) compared with the mass-weighted average values of coal briquettes and biomass briquettes. 88.8 ± 11.8%, 136.7 ± 13.7% and 81.4 ± 17.7% more TEs were provided by wheat straw–coal briquettes, rice straw–coal briquettes and maize straw–coal briquettes. 93.3 ± 3.1% (wheat straw–coal), 97.6 ± 0.2% (rice straw–coal) and 90.4 ± 2.2% (maize straw–coal) in terms of PM2.5 emission factors (EFs) was reduced. For bio-coal briquette, a 25 MPa and 10% addition were determined as the optimum molding pressure and clay addition ratio. Bio-coal briquettes with higher TEs and lower PM EFs will bring about substantial benefits for air quality promotion, human health and energy saving.

Hydrogen Enrichment Effects in Gaseous Fuels on Distributed Combustion

2019 ◽  
Author(s):  
Serhat Karyeyen ◽  
Joseph S. Feser ◽  
Ashwani K. Gupta
Keyword(s):  
Oxygen Concentration ◽  
Hydrogen Content ◽  
Reaction Rates ◽  
Flame Speed ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Flame Stability ◽  
Limited Information ◽  
High Hydrogen ◽  
Gaseous Fuels

Abstract High intensity colorless distributed combustion has been a promising combustion technique as it enables much reduced pollutant emissions such as NO and CO, as well as more thermal uniformity, flame stability and combustion efficiency. The main requirement for achieving distributed conditions is to provide controlled entrainment of reactive hot product gases into the fresh mixture prior to ignition. In this way, the oxygen concentration is reduced, which results in lower reaction rates, promoting longer mixing times and volumetric distribution of the reaction zones. Though distributed combustion has been extensively studied for various heat loads and intensities, fuels, geometries, there is limited information related to fuel flexibility. Therefore, it is of interest to investigate hydrogen enriched gaseous fuels for greater understanding of low calorific high flame speed fuels in a distributed combustion system. Three various hydrogen content gaseous fuel (40–60% by volume) were investigated in a swirl-stabilized burner for this study, through the use of either N2 or CO2 as the diluent in order to achieve distributed conditions. The OH* chemiluminescence flame signatures were obtained in the flame front and emissions were measured from the combustor exit. The results showed that both the hydrogen concentration and diluent type considerably impacted the oxygen concentration at which transition to CDC occurred. Distributed conditions were achieved at oxygen concentrations of 10–12% with entrained N2 and 13–15% with entrained CO2 for various gaseous fuels consumed. It was determined that the transition to CDC occurred at a lower oxygen concentration for high hydrogen content fuels due to the higher flame speed of hydrogen. The flame images demonstrated that the flashback propensity of the gaseous fuels were eliminated and enhanced flame stability was achieved under the favorable CDC conditions. For NO pollutant emission, ultra-low NO level was achieved under CDC (less than 1 ppm) while CO pollutant emission decreased gradually with condition approaching distributed conditions, and then increased slightly due to the lower flammability limit and dissociation of CO2.

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