The Effect of Percentage of CO2 on the Biogas Counterflow Diffusion Flame Stability

2014 ◽  
Vol 664 ◽  
pp. 221-225
Author(s):  
Mega Nur Sasongko
Keyword(s):  
Mass Flow Rate ◽  
Oxygen Concentration ◽  
Mass Flow ◽  
Flow Rate ◽  
Diffusion Flame ◽  
Flame Stability ◽  
Low Oxygen ◽  
Fuel Flow ◽  
Counterflow Diffusion Flame ◽  
Low Oxygen Concentration

This study aims to determine the effect of the percentage of CO2 in the biogas to the characteristics of biogas diffusion flame. Counterflow configuration was used in this study to investigate detail structure of diffusion flame and the flame stability of biogas. The concentration of CO2 in the biogas was varied from 0% to 50% while the mass flow rate of the reactants was varied from 4 to 14 L / min. The results showed that the CO2 in the biogas fuel affect the diffusion flame characteristics, especially the area of luminous yellow flame formed in the fuel flow. In the low oxygen concentration, percentage of CO2 did not affect the diffusion flame stability. However, the flame stability was more influenced by the rate of diffusion between fuel and oxygen. Therefore, the combustion of biogas is more recommended to be done in the low oxygen concentration.

Experimental Study of Spray Flame Characteristics in Hot-Diluted Oxidant Through Advanced Image Processing Technique

2017 ◽  
Author(s):  
Yuan Li ◽  
Hao Zhou ◽  
Ning Li ◽  
Kefa Cen
Keyword(s):  
Image Processing ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Air Mass ◽  
Fuel Flow ◽  
Spray Flame ◽  
Oxygen Concentrations

This paper presents a study of ethanol jet spray flame characteristics in a hot-diluted oxidant with different co-flow oxygen concentrations and fuel/air mass flow rate ratios (MF/MA ratios) through advance image processing technique. An air-blast atomizer was located in a McKenna burner which was utilized to provide stable combustion surroundings and variable combustion atmosphere for ethanol jet spray. The co-flow oxygen concentrations were set to 5%, 10%, 15% and 21% (by volume) by adjusting the mass flow rates of CH4, O2 and N2. The MF/MA ratios were set to 0.245, 0.490, 0.735, and 0.980 by adjusting the fuel mass flow rate and the carrier air mass flow rate. A high-speed RGB CCD camera was employed to capture spray flame images continuously. Spray flame edge is detected using an auto-adaptive edge-detection algorithm which could detect the spray flame edge continuously and clearly. A flame zone is defined as the region surrounded by the detected flame edge to obtain flame parameters. Spray flame characteristics are described using the measured flame parameters, involving flame area, length, brightness, nonuniformity and temperature which are derived from the spray flame images. Spray flame area, length, brightness and nonuniformity are extracted through image processing technique directly. Moreover, two-dimensional (2D) temperature profiling of spray flame is obtained by coupling image processing technique with two-color pyrometry based on Planck’s radiation law. The effects of co-flow oxygen concentration and MF/MA ratio on spray flame characteristics are investigated in this work. The spray flame parameters are observed to be sensitive to both co-flow oxygen concentration and MF/MA ratio. The results show that the fuel mass flow rate (MF) has opposite effects on spray flame characteristics compared with the carrier air mass flow rate (MA) in hot-diluted oxidant. Spray flame area and length are shown to decrease for higher co-flow oxygen concentrations, while spray flame brightness, uniformity and temperature are observed to increase for higher co-flow oxygen concentrations, owing to the enhancement of the combustion rate. A higher MF/MA ratio leads to higher spray flame area, length, brightness, uniformity and temperature, due to the increase of the droplet residence time or droplet concentration in hot-diluted oxidant. In the same MF/MA ratio, spray flame area and length are found to be smaller at a higher fuel flow rate (or carrier air flow rate). However, spray flame brightness, uniformity and temperature are demonstrated to be enhanced at a higher fuel flow rate (or carrier air flow rate). (CSPE)

Effects of Burner Diameter and Fuel Type on Smoke Point and Radiation Characteristics of Diffusion Flames

2002 ◽  
Author(s):  
S. F. Goh ◽  
S. Kusadomi ◽  
S. R. Gollahalli
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Critical Mass ◽  
Smoke Point ◽  
Fuel Type ◽  
Fuel Flow Rate ◽  
Flame Radiation ◽  
Fuel Mass ◽  
Fuel Flow

The main purpose of this study was to comprehend the effects of burner diameter and fuel type on smoke point characteristics of a hydrocarbon diffusion flame and its radiation emission. The critical mass flow rate of pure fuel at this smoke point was measured. At nine different fractions of the critical mass flow rate, nitrogen gas was supplied along with the fuel to achieve smoke point. At each condition, flame radiation and flame height were measured. The axial radiation profile at the critical fuel mass flow rate for one burner was also measured. Three fuels of differing sooting propensities were used: ethylene (C2H4), propylene (C3H6), and propane (C3H8). Three different burners with inner diameters of 1.2 mm, 3.2 mm and 6.4 mm were used. Results showed that propylene had the highest critical fuel flow rate and the highest nitrogen dilution required to suppress smoking and total flame radiation, followed by ethylene and propane. For all fuels, the curves of nitrogen flow rate required for smoke suppression versus fuel flow rate exhibited a skewed bell shape. The variation of Reynolds number at the critical fuel mass flow rate with the burner diameter showed a linear relation. On the other hand, the variation of total flame radiation with burner diameter was nonlinear.

Computational Study of Fuel Dilution Effect on the Soot Formation in Methane-Air Laminar Confined Diffusion Flame

2013 ◽  
Author(s):  
Achin Kumar Chowdhuri ◽  
Arindam Mitra ◽  
Somnath Chakraborti ◽  
Bijan Kumar Mandal
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Diffusion Flame ◽  
Volume Fraction ◽  
Soot Formation ◽  
Soot Volume Fraction ◽  
Flame Height ◽  
Fuel Jet ◽  
Fuel Stream

Although diffusion flame is free from many problems associated with premixed flame, soot formation is a major problem in diffusion flame. The techniques of dilution of fuel or air with inert gases such as nitrogen and argon are used to decrease soot level in the flame. In this work, a CFD code has been developed to predict the flame height, soot volume fraction and soot number density in an axisymmetric laminar confined methane-air diffusion flame after diluting the fuel with nitrogen. The temperatures of the air and fuel at inlet are taken as 300K. Mass flow rate of the fuel stream is considered as 3.71×10−6 kg/s and mass flow rate of the air is taken as 2.2104×10−6 kg/s. The total mass flow rate through the central jet (fuel jet) is, however, kept constant. The radiation effect is also included through an optically thin radiation model. An explicit finite difference technique has been adopted for the numerical solution of reacting flow and two equations soot model with variable thermodynamic and transport properties. The prediction shows that flame height decreases with the addition of nitrogen to the fuel. Temperature of the flame is considerably reduced in the given computational domain. Both soot volume fraction and soot number density decrease with dilution by adding nitrogen in the fuel jet. The soot formation at different nitrogen dilution level of 0%, 10%, 20%, 30%, 40% and 50% are plotted and the soot get considerably reduced as the concentration of nitrogen is increased in the fuel stream.

scholarly journals Gas Turbine Tubular Combustor Main Injector Optimization for Low Emission Combustion

2018 ◽  
Vol 26 (10) ◽  
pp. 1-12
Author(s):  
Arkan Khikhal Husain ◽  
Mahmood Attallah Mashkoor ◽  
Fuad Abdul Ameer Khalaf
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
High Performance ◽  
Atmospheric Conditions ◽  
Air Mass ◽  
Fuel Flow ◽  
Low Emission ◽  
Gas Fuel

This work presents the experimental investigation results of high performance and low emission colorless combustion in a gas turbine tubular combustor at atmospheric conditions. Low emission and colorless oxidation reaction is characterized by dispersed flame and temperature under the conditions of preheated air. System performance, emissions of CO and UHC are recorded up to achieve low emission colorless combustion, the flame capturing, Measurements of temperature, inlet air mass flow rate and gas fuel LPG flow rate for variable of fuel main injector holes diameter. concluded that maximal air mass flow rate, with choked fuel flow in the main injector for each cases promotes the formation of colorless pal blue flame combustion, for 3.2 g/s of fuel flow rate with 6 holes and 1mm main injector holes diameter and lower CO emissions and decreasing in UHC emissions (70 → 10) ppmv with increasing in power generation (0.5 → 3.42) kW and decreasing in S.F.C. (21.5 → 3.49) kg/kwh.

Effects of Jet Dilution and Co-Flow on Sooting Characteristics of Hydrocarbon Fuels

2001 ◽  
Author(s):  
S. F. Goh ◽  
S. Kusadomi ◽  
S. R. Gollahalli
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Critical Mass ◽  
Hydrocarbon Fuels ◽  
Nitrogen Flow Rate ◽  
Fuel Flow Rate ◽  
Radiation Emission ◽  
Fuel Flow ◽  
Nitrogen Dilution

Abstract A study was conducted to understand the effects of dilution and co-flow on the sooting characteristics of hydrocarbon fuels. Measurements of the critical mass flow rate of a fuel at the threshold of smoking and the mass flow rate of the dilution gas (nitrogen) required to suppress smoking at several fuel flow rates were obtained. At the same time, the radiation emission and flame heights were also measured. Also recorded was the axial radiation profile at the critical fuel mass flow rate. Three fuels of differing sooting propensities were used: ethylene (C2H4), propylene (C3H6), and propane (C3H8). A 3.2 mm ID burner was employed. The results showed that propylene had the highest critical fuel flow rate and the highest nitrogen dilution required to suppress smoking, followed by ethylene and propane. Besides, propylene produced the highest flame radiation, followed by ethylene and propane. The variation of nitrogen flow rate required for smoke suppression with fuel flow rate exhibited a skewed bell shape for all fuels. The co-flow had no significant effect on flame soot liberation characteristics.

Numerical Analysis of a Kerosene-Fueled Scramjet Combustor

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Malsur Dharavath ◽  
P. Manna ◽  
P. K. Sinha ◽  
Debasis Chakraborty
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Fuel Injection ◽  
Wall Pressure ◽  
Test Facility ◽  
Reacting Flow ◽  
Significant Drop ◽  
Scramjet Combustor ◽  
Fuel Flow

A kerosene-fueled scramjet combustor was numerically analyzed in order to meet the requirement of thrust for a hypersonic test vehicle. The internal configuration of the fuel injection struts and fuel injection was arrived through computational fluid dynamics (CFD) study. The combustor was tested in the hypersonic test facility at DRDL. Numerical simulations were carried out along with facility nozzle (from throat onward) both for nonreacting and reacting flow. Three-dimensional (3D) Reynolds-averaged Navier–Stokes (RANS) equations are solved along with k–ε turbulence model. Single-step chemical reaction with Lagrangian particle tracking method (LPTM) is used for combustion of kerosene fuel. Fairly good match of the top wall pressure has been obtained with experimental data for both nonreacting and reacting flows. Effects of mass flow rate of incoming vitiated air and fuel flow have been studied numerically in details. Top wall pressure distributions have been found to decrease with the decrease of the mass flow rate of vitiated air. Significant drop of wall pressure, higher thrust per unit fuel flow, and combustion efficiency have been observed with the decrease of fuel flow.

Development of a Temporally Modulated Fuel Injector With Controlled Spray Dynamics

2002 ◽  
Vol 125 (1) ◽  
pp. 284-291 ◽  
Author(s):  
H. Chang ◽  
D. Nelson ◽  
C. Sipperley ◽  
C. Edwards
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Combustion Instability ◽  
Cone Angle ◽  
Fuel Injector ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
Spray Distribution

It is now well established that combustion instability in liquid-fueled gas turbines can be controlled through the use of active fuel modulation. What is less clear is the mechanism by which this is achieved. This results from the fact that in most fuel modulation strategies not only is the instantaneous mass flow rate of fuel affected but so too are the parameters which define the post-atomization spray that takes part in the combustion. Specifically, experience with piezoelectric modulated sprays has shown that drop size, velocity, cone angle, and patternation are all affected by the modulation process. This inability to decouple changes in the fueling rate from changes in the spray distribution makes understanding of the mechanism of instability control problematic. This paper presents the results of an effort to develop an injector which can provide temporal modulation of the fuel flow rate but without concomitant changes in spray dynamics. This is achieved using an atomization strategy which is insensitive to both fuel flow rate and combustor acoustics (an over-pressured spill-return nozzle) coupled with an actuator with flat frequency response (a low-mass voice coil). The design and development of the actuator (and its control system) are described, and a combination of phase-Doppler interferometry and imaging are used to establish its performance. Results show that the system is capable of producing sprays which have little variation in cone angle or spray distribution function despite variations in mass flow rate (number density) of greater than 50% over a range of frequencies of interest for control of combustion instability (10 Hz to 1 kHz).

Development of a Temporally Modulated Fuel Injector With Controlled Spray Dynamics

2001 ◽  
Author(s):  
Hyeonsoo Chang ◽  
Chad Sipperley ◽  
David Nelson ◽  
Chris Edwards
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Combustion Instability ◽  
Cone Angle ◽  
Fuel Injector ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
Spray Distribution

It is now well established that combustion instability in liquid-fueled gas turbines can be controlled through the use of active fuel modulation. What is less clear is the mechanism by which this is achieved. This results from the fact that in most fuel modulation strategies not only is the instantaneous mass flow rate of fuel affected but so to are the parameters which define the post-atomization spray that takes part in the combustion. Specifically, experience with piezoelectric modulated sprays has shown that drop size, velocity, cone angle, and patternation are all affected by the modulation process. This inability to decouple changes in the fueling rate from changes in the spray distribution makes understanding of the mechanism of instability control problematic. This paper presents the results of an effort to develop an injector which can provide temporal modulation of the fuel flow rate but without concomitant changes in spray dynamics. This is achieved using an atomization strategy which is insensitive to both fuel flow rate and combustor acoustics (an over-pressured spill-return nozzle) coupled with an actuator with flat frequency response (a low-mass voice coil). The design and development of the actuator (and its control system) are described, and a combination of Phase-Doppler Interferometry and imaging are used to establish its performance. Results show that the system is capable of producing sprays which have little variation in cone angle or spray distribution function despite variations in mass flow rate (number density) of greater than 50% over a range of frequencies of interest for control of combustion instability (10 Hz to 1 kHz).

The standard unit mass flow rate of gas-liquid mixtures

2020 ◽  
pp. 13-16
Author(s):  
V.N. Petrov ◽  
◽  
V.F. Sopin ◽  
L.A. Akhmetzyanova ◽  
Ya.S. Petrova ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Liquid Mixtures ◽  
Unit Mass ◽  
Standard Unit

Prediction of Leakage Mass Flow Rate Through Gas Springs

1987 ◽  
Author(s):  
Roberto Bruno Bossio ◽  
Vincenzo Naso ◽  
Marian Cichy ◽  
Boleslaw Pleszewski
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate
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