scholarly journals Analysis of Product and Temperature of Biogas Combustion in Various Air Biogas Equivalence Ratio and Methane Content

2018 ◽  
Vol 18 (2) ◽  
pp. 211
Author(s):  
Arini Wresta ◽  
Aep Saepudin
Keyword(s):  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Methane Content ◽  
Combustion Reaction ◽  
Combustion Characteristic ◽  
Inert Material ◽  
Complete Combustion ◽  
Combustion Gases ◽  
Degraded Material ◽  
Higher Temperature

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.

The Effect of Biomass Shapes on Combustion Characteristic in Updraft Chamber

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
Wasu Suksuwan ◽  
◽  
Mohd Faizal Mohideen Batcha ◽  
Arkom Palamanit ◽  
Makatar Wae-hayee ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Combustion Chamber ◽  
Combustion Temperature ◽  
Ambient Air ◽  
Combustion Characteristics ◽  
Flue Gases ◽  
Combustion Characteristic ◽  
Rubber Wood ◽  
Chip Shape ◽  
Biomass Sample

Combustion of agricultural residues and wastes for energy applications is still popular. However, combustion of biomass with different shapes leads to many side effects such as agglomeration, emission and incomplete combustion. The aim of this study was therefore to investigate the effects of biomass shapes on combustion characteristics in an updraft combustion chamber. The rubber wood chip, coconut shell, oil palm empty fruit bunch, corn straw, rubber wood sawdust, and mixed palm cake were used as fuel and they were categorized as 3 shapes namely, chip shape, fiber shape, and powder shape. The biomass sample was combusted in simple cylindrical shape combustion chamber. The diameter of combustion chamber was 20 cm and its height was 160 cm. The biomass sample (moisture content below 20%) with amount of 1 kg was used to perform the experiment. The ambient air that had velocity of 0.50, 0.75 and 1.00 m/s (corresponding to an equivalence ratio of 1-3.5) was supplied to combustion chamber. The temperature at different positions along combustion chamber height and the properties of flue gases (carbon monoxide) were then measured. The results showed that the biomass shape had effect on combustion characteristics. Combustion of fiber shape biomass led to low combustion temperature, while the carbon monoxide in flue gases was high. This indicates the improper combustion process. The chip shape biomass was well combusted at a higher air velocity and the flue gases had lowest carbon monoxide. The highest combustion temperature was obtained from combustion of powder shape biomass. However, it led to the problem of unburned biomass such in case of sawdust. This is because the sawdust powder was carried from combustion chamber before burning completely.

Numerical and Experimental Investigations on Liner Heat Transfer in an Aero Engine Combustion Chamber

2017 ◽  
Author(s):  
Korukonda Venkata Lakshmi Narayana Rao ◽  
B. V. S. S. S. Prasad ◽  
Ch. Kanna Babu ◽  
Girish K. Degaonkar
Keyword(s):  
Combustion Chamber ◽  
Structural Integrity ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Numerical Computations ◽  
Combustion Gases ◽  
Flow Characterization ◽  
Aero Engine ◽  
Straight Flow ◽  
Flow Variables

The Gas turbine combustion chamber is the highest thermally loaded component where the temperature of the combustion gases is higher than the melting point of the liner that confines the gases. Combustor liner temperatures have to be evaluated at all the operating conditions in the operating envelope to ensure a satisfactory liner life and structural integrity. On experimental side the combustion chamber rig testing involves a lot of time and is very expensive, while the numerical computations and simulations has to be validated with the experimental results. This paper is mainly based on the work carried out in validating the liner temperatures of a straight flow annular combustion chamber for an aero engine application. Limited experiments have been carried out by measuring the liner wall temperatures using k-type thermocouples along the liner axial length. The experiments on the combustion chamber testing are carried out at the engine level testing. The liner temperature which is numerically computed by CHT investigations using CFX code is verified with the experimental data. This helped in better understanding the flow characterization around and along the liner wall. The main flow variables used are the mass flow rate, temperature and the pressure at the combustor inlet. Initially, the fuel air ratio is used accordingly to maintain the same T4/T3 ratio. The effect of liner temperature with T3 is studied. Since T4 is constant, the liner temperature is only dependent on T3 and follows a specific temperature distribution for the given combustor geometry. Hence this approach will be very useful in estimating the liner temperatures at any given T3 for a given combustor geometry. Further the liner temperature is also estimated at other fuel air ratios (different T4/T3 ratios) by using the verified CHT numerical computations and found that TL/T3 remains almost constant for any air fuel ratio that is encountered in the operating envelope of the aero engine.

scholarly journals Experimental determination of a mass loss of biomass pellets at different temperatures of the combustion chamber combusted in a stream of inert material

2019 ◽  
Vol 82 ◽  
pp. 01007
Author(s):  
Katarzyna Kaczyńska ◽  
Konrad Kaczyński ◽  
Piotr Pełka
Keyword(s):  
Mass Loss ◽  
Combustion Chamber ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Circulating Fluidized Bed ◽  
Combustion Process ◽  
Inert Material ◽  
Mass Rate ◽  
Different Temperatures

In the herein paper, research on the mass loss of biomass pellets is presented. The research was carried out on a specially constructed test stand. In the research three types of pellet fuels were used, which were made of oak sawdust, sunflower husk and straw. The research was carried out at three different temperatures of the combustion chamber: 850°C, 750°C and 650°C. The research was carried out without inert material and mass rate flow Gs=2,5kg/m2s and Gs=5kg/m2s. Quartz sand was the inert material. It was expected that an increase in the temperature prevailing in the combustion chamber would accelerate the process of mass loss of the biomass pellet combustion. However, the results of the experiment indicated that this is not the case in every analyzed case. The mass flow rate of inert material intensifies the combustion process and accelerates the biomass pellets made of oak sawdust mass loss, but increasing the temperature in the combustion chamber accelerates the process of biomass pellets mass loss more than the mass flow rate of inert material. Based on the experimental tests carried out, it was found that biomass can be combusted in circulating fluidized bed boilers, albeit due to the diversified chemical composition of the biomass (alkali content), the boiler should be operated in such a way as to prevent the softening and melting temperature of the ash being exceeded.

Simulation of Pollutant Emissions in a Small-Sized Combustion Chamber With a Gas Fuel for Various Regime Modes

2019 ◽  
Author(s):  
Nikita I. Gurakov ◽  
Ivan A. Zubrilin ◽  
Ivan V. Chechet ◽  
Vladislav M. Anisimov ◽  
Sergey S. Matveev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Combustion Products ◽  
Pollutant Emissions ◽  
Eddy Simulation ◽  
Flamelet Generated Manifold ◽  
Combustion Processes

Abstract The study shows the results of the emission simulation in a small-sized combustion chamber. The influence of temperature and equivalence ratio on CO and CxHy in the combustion chamber was investigated. Experiments and calculations were carried out for the following modes: temperature at the inlet of the combustion chamber Tinlet = 323 ... 523 K; equivalence ratio φ = 0.2 ... 0.33; normalized flow rate at the inlet of the combustion chamber λ = 0.1 ... 0.3. The simulation of combustion of natural gas was carried out. The studies were conducted using CFD software and experimental methods. Measurements of the combustion products composition were carried out by the method of sampling collection and subsequent chromatographic analysis. The flow and combustion processes were simulated in a three-dimensional steady formulation using the Reynolds-averaged Novier-Stokes equations (RANS) and in a transient formulation using the Large Eddy Simulation (LES) method. The combustion processes were simulated by Flamelet Generated Manifold model in conjunction with the probability density function method (PDF). In addition to the above methods, the method of the reactor network model (RNM) was used to simulate the emission. As a result, a comparison of the calculated and experimental data of concentrations values of combustion products and emissions indices averaged over the combustion chamber outlet was conducted. According to the results of the calculated-experimental study obtained: - the simulated concentrations values of the main combustion products such as CO2 and H2O qualitatively and quantitatively coincide with the experimental data (the discrepancy is less than 5%) for all three approaches — RANS, LES, RNM; - when modeling CO emissions, the discrepancy between the calculated emission indices obtained by the RANS and LES methods is greatly underestimated relative to the experimental data, whereas the values calculated by the RNM method deviate from the experiment by less than 10%; - mass concentration values of unburned hydrocarbons obtained by the RANS method are overestimated relative to the experimental values, while using the LES with RNM methods, the discrepancy does not exceed 10%.

INVESTIGATION ON CHARACTERISTICS OF POME BLENDED DIESEL ENGINE

2015 ◽  
Vol 75 (8) ◽  
Author(s):  
Helmisyah Ahmad Jalaludin ◽  
Mohd Ruysdi Ramliy ◽  
Nik Rosli Abdullah ◽  
Salmiah Kasolang ◽  
Shahrir Abdullah ◽  
...  
Keyword(s):  
High Temperature ◽  
Combustion Chamber ◽  
Fuel Consumption ◽  
Oxygen Content ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Sudden Increase ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Complete Combustion

The sudden increase in fuel prices due to diminishing petroleum resources and the pollution resulting from its use has resulted in research into alternative fuels such as biodiesel. In addition, the faster combustion and high temperature in the combustion chamber which results from petroleum diesel fuel leads to higher nitrogen oxide (NOx) and Particulate Matter (PM) emissions. Therefore, this research was conducted to investigate the effect of using palm oil methyl ester (POME) blends as alternative fuels on the performance and emission of a compression ignition engine. The performance of POME blends and diesel were compared by manipulating the load of the engine at 1800 rpm. The results obtained show that fuel consumption rate is higher for the POME blends compared to the diesel fuel and increases as the POME concentration increases. The increment of brake specific fuel consumption and the reduction of CO emission exhibit a relation to the increase in percentage of POME. This is mainly contributed by the higher oxygen content of POME which promotes complete combustion of the blends. However, efficient combustion from the blends as compared to diesel fuel resulted from higher oxygen content and cetane number leads to significant increase in exhaust temperature. This in turn increases NOx emissions since using POME blends is highly related to high temperature of combustion chamber. The experimental results proved that POME in compression ignition engine is a possible substitute to diesel.

Effect of Dilation-Angle on Combustion Characteristic in Two-Phase Combustion Chamber with Dilative Entrance

2011 ◽  
Vol 52-54 ◽  
pp. 806-811
Author(s):  
Hai Bo Lu ◽  
Wei Qiang Liu
Keyword(s):  
Combustion Chamber ◽  
Evaporation Rate ◽  
Thermal Protection ◽  
Combustion Characteristic ◽  
Two Phase ◽  
Liquid Component ◽  
Dilation Angle ◽  
Different Characteristics

The GO2/ethanol/water tripropellant evaporation and combustion in axisymmetric combustion chamber was numerically simulated. The different characteristics of the evaporation and combustion between dilative and traditional un-dilative entrance, and the different dilation-angles of the combustion chamber entrance are analyzed. The results indicate that the dilative entrance combustion chamber is benefit for thermal protection of the injection, and the flamelet backpedals with increase of the entrance dilation-angle. At the same time, that dilative inlet combustion chamber reduces the evaporation of the liquid component seriously. The evaporation rate decreases with the increase of the dilation-angle at first, but after the dilation-angle is bigger than a critical one, it increases.

scholarly journals Experimental study on combustion of CH4/NH3 fuel blends in an industrial furnace operated in flameless conditions

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3625-3635
Author(s):  
Rafal Slefarski ◽  
Pawel Czyzewski ◽  
Michal Golebiewski
Keyword(s):  
Experimental Study ◽  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Molar Fraction ◽  
Combustion Process ◽  
Steel Production ◽  
Methane Combustion ◽  
Efficient Technology ◽  
Flameless Combustion ◽  
Fuel Blends

This paper presents the results of an experimental study on the combustion process of methane mixed with NH3 in flameless mode. At a time of striving for CO2-free power, NH3 became a potential energy storage carrier fuel from renewable sources. Flameless combustion features low emissions and is a very efficient technology used in the power sector, as well as steel production, ceramics, etc. Industrial furnaces were tested in the context of pure methane combustion with an addition of NH3, up to 5%. Flameless combustion conditions were achieved with a regenerative gas burner system (high regenerative system). The burner consists of four ceramic regenerators allowing for continuous preheating of air, even up to 50 K lower than the temperature of the combustion chamber wall. Constant power of the introduced fuel was kept at 150 kW and the fuel-air equivalence ratio ranged from 0.75 to 0.95. The results have shown a growth of molar fraction of NO in flue gases when NH3 content in the fuel rose. The increase is more significant for the tests with a higher amount of oxygen in the combustion chamber (a lower fuel-air equivalence ratio). An addition of 5% of NH3 into the fuel caused an emission of NO at the levels of 113 ppmv and 462 ppmv (calculated to O2 = 0%), respectively for low and high fuel-air equivalence ratios.

scholarly journals Effect of Using Power Air Screw And Cyclone On Air – Fuel Equivalence Ratio And Monoxide Carbon Gas Emissions In Four Stroke Gasoline Engines

Tibuana ◽  
2021 ◽  
Vol 4 (01) ◽  
pp. 49-54
Author(s):  
Syamsul Arifin
Keyword(s):  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Fuel Mixture ◽  
Petrol Engine ◽  
Gas Emissions ◽  
Gasoline Engines ◽  
The Third

The experience is observed for fourstrokes petrol engine for revolution 1000 rpm - 4000 rpm, with used of power air screw oncarburator and cyclone on outlet intakemanifold. Air – fuel mixture have passed ofcyclone to combustion chamber to becometurbulent flow and homogen. Then theexperience of step by step used power screwand cyclone. The first investigation on standarcondition, the second put of power air screwon carburator, the third put of cyclone on outletintake manifold, the fourth put of combinationof power air screw and cyclone. It wasobserving for increasing air – fuel equivalenceratio and reduction of exhaust COconcentration. Actually, used combination ofpower air screw and cyclone are resulted ofcarbon monoxide concentration drop ofenough significant for 2500 rpm and 4000 rpm,respectively 51% and 67%. The carbonmonoxide least concentration is 1,14% oncondition 4000 rpm.

scholarly journals Mechanism of self-propagating hightemperature synthesis of AlB2‒Al2O3

2019 ◽  
pp. 27-36
Author(s):  
Pan Yang ◽  
Guoqing Xiao ◽  
Donghai Ding ◽  
Yun Ren ◽  
Zhongwei Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Ignition Temperature ◽  
Combustion Reaction ◽  
Peritectic Temperature ◽  
Composite Powders ◽  
Temperature Synthesis ◽  
Precipitation Mechanism ◽  
High Temperature Synthesis ◽  
Higher Temperature ◽  
Quenching Method

The mechanism of self-propagating high-temperature synthesis (SHS) of AlB2‒Al2O3 composite powders was studied by means of a combustion front quenching method (CFQM). The results showed that combustion reaction started with the melting of B2O3 and Al particles. As the combustion reaction proceeded, the interpenetration of Al and B2O3 in melts happened. The XRD results of the product revealed the reflections of Al2O3, suggesting there had been an exchange of oxygen atoms between Al and B, and evidencing the reaction, B2O3 (l) + 2Al (l) → 2B (s) + Al2O3 (l). Under higher temperature, some of B2O3 volatilized and reacted with B forming gaseous B2O2, which deposited on the surface of Al to precipitate Al2O3 and B. Then B made available dissolved into Al melt, and reacted with the Al in melt to precipitate AlB12 particles. Finally, AlB12 transforms to AlB2 at the peritectic temperature under high cooling rate. Thus, this combustion reaction can be described by the dissolution-precipitation mechanism. In the final products, besides AlB2 and Al2O3 particles, some of Al was also detected. A model corresponding to the dissolutionprecipitation mechanism was proposed, and the ignition temperature of the combustion reaction was determined to be around 800 °C. Ill. 13. Ref. 47.

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