TED-AJ03-608 EXTINCTION OF THE COUNTERFLOW DIFFUSION FLAME OF BLENDED FUELS
スポンサーリンク
概要
- 論文の詳細を見る
For applications of the high-temperature air combustion technology (HiCOT) to waste incinerators, diffusion flames of blended fuel gases and high-temperature air in the stretch flow field were investigated. In this study, extinction limits of the counterflow diffusion flame for CH_4-C_3H_8 blended fuel gases were obtained experimentally and numerically, varying the mixture fraction, fuel concentration, air temperature, and flame stretch rate. Since the flame is unable to stabilize at small stretch rates due to the natural convection caused by buoyancy under normal gravity condition, the experiments were performed under microgravity condition using JAMIC dropshaft in Hokkaido, Japan. Numerical analysis was performed considering detail chemistry and radiative heat loss using the optically thin model. Experimental and numerical results showed that, when the blended fuel is used air temperature is increased, extinction limits are expanded (Figs. A-1 and A-2). As increasing air temperature, however, the extinction limits at low stretch rates are not expanded as much as those at high stretch rates. This reason is presumed as follows : At the high stretch rate region in which the so-called stretch extinction occurs, Damkohler number becomes small and the flame temperature decreases rapidly, so that flame extinguishes; that is, the characteristic chemical reaction time becomes longer than the characteristic flow time. As the air temperature is elevated, the reaction rate increases according to the Arrhenius law. As a result, combustion stabilization is significantly improved and the extinction limit on the high stretch rate side is expanded largely. On the other hand, so-called radiation extinction occurs on the low stretch rate side, owing to a wide flame region with high temperature. The reaction rate increases when the air temperature increases and therefore the extinction limit must be expanded as well. Radiation heat loss, however, also increases in proportion to temperature to the power 4,since the flame temperature becomes higher as the air temperature increases. This is the reason why the extinction limit does not so much expand in low stretch rates as it expands in high stretch rates.[figure]
- 一般社団法人日本機械学会の論文
著者
-
KOBAYASHI Hideaki
Institute of Fluid Science, Tohoku University
-
Niioka Takashi
Institute Of Fluid Science Tohoku University
-
Maruta Kaoru
Institute Of Fluid Science Tohoku University
-
Tomohiro Denda
Institute of Fluid Science, Tohoku University
-
Tomohiro Denda
Institute Of Fluid Science Tohoku University
-
Kobayashi Hideaki
Institute Of Fluid Science Tohoku University
関連論文
- Development of an Ethanol Reduced Kinetic Mechanism Based on the Quasi-Steady State Assumption and Feasibility Evaluation for Multi-Dimensional Flame Analysis
- Numerical Study of NO_x Emission in High Temperature Air Combustion
- Experimental Study on Spray Characteristics of Prefilming Airblast Atomizer
- Influence of Combustor Inlet Conditions on Combustot Exit Gas Peak Temperature Factor (Experiment by using the Combustor with Pressure Atomizing Fuel Nozzles and the Combustor with Airblast Type Fuel Injectors)
- Study on the Correlation of the Altitude Ignition Parameter and Lightoff Air Fuel Ratio for Jet Engine Combustors
- B104 IGNITION TIMES OF n-DECANE DROPLET ARRAY IN HIGH-TEMPERATURE LOW-SPEED AIRFLOW(Droplet/particle combustion-1)
- Stability Limits of Swiss-roll Micro Combustors
- Emission and Efficiency of Small Swiss-Roll Combustors as Heat Sources
- Effect of the Location of an Incident Shock Wave on Combustion and Flow Field of Wall Fuel-Injection
- Numerical Analysis of Combustion around a Strut in Supersonic Airflow
- Laminar Burning Velocity of Stoichiometric CH_4/air Premixed Flames at High-Pressure and High-Temperature
- A Study of Interaction between Shock Wave and Cross-Flow Jet Using Particle Tracking Velocimetry
- Effects of Turbulence on Flame Structure and NOx Emission of Turbulent Jet Non-Premixed Flames in High-Temperature Air Combustion(Advanced Fluid Information)
- TED-AJ03-375 A STUDY OF LAMINAR BURNING VELOCITY FOR H_2/O_2/He PREMIXED FLAME AT HIGH PRESSURE AND HIGH TEMPERATURE
- Asymptotic Analysis on the Extinction of Diffusion Flames in Supersonic Stagnation-Point Flow
- Experiments on Flame Spread of a Fuel Droplet Array in a High-Pressure Ambience
- Flame Stabilization Mechanism of a Newly Devised Strut for the Scramjet Engine
- TED-AJ03-608 EXTINCTION OF THE COUNTERFLOW DIFFUSION FLAME OF BLENDED FUELS
- TED-AJ03-616 Extinction Limits of Counterflow Diffusion Flames of CO, H_2,CH_4 and Their Blends
- Structures and Stability of Lifted Combustion Zones in Preheated Oxidizer(Special Issue on International Conference on Power and Energy System)
- TED-AJ03-400 Radiation Reabsorption Effects on NO Emission from High-Temperature Air/CH_4 Counterflow Diffusion Flames
- Numerical Simulation of Ignition in Supersonic Reactive Shear Layers
- TED-AJ03-520 THE NUMERICAL SIMULATION ON UNSTABLE BEHAVIORS OF PREMIXED FLAMES GENERATED BY HYDRODYNAMIC AND DIFFUSIVE-THERMAL EFFECTS
- Dynamic Behavior of Premixed Flames Propagating in Non-Uniform Velocity Fields : Assessment of Intrinsic Instability in Turbulent Combustion
- Numerical Analysis of Extremely-rich CH4/O2/H2O Premixed Flames at High Pressure and High Temperature Considering Production of Higher Hydrocarbons
- Numerical Study of Radiation Effects on Polypropylene Combustion Using High-temperature Oxidizer Diluted with H2O and CO2
- Numerical Study on the Intrinsic Instability of High-Temperature Premixed Flames under the Conditions of Constant Density and Constant Pressure in the Unburned Gas