scholarly journals DME-Fired Water-Tube Boiler: An R&D Study

2005 ◽  
Author(s):  
Mamoru Ozawa ◽  
Ryosuke Matsumoto ◽  
Nobuo Higuchi ◽  
Yoshio Hayashi ◽  
Hiroki Uematsu ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
Ignition Temperature ◽  
Burning Velocity ◽  
Effective Means ◽  
Premixed Flame ◽  
Water Tube ◽  
City Gas ◽  
Combustion Technology ◽  
Low Nox Combustion ◽  
Further Development

Increasing attention has been given to the development of low-NOx combustion technology for DME (Dimethyl Ether). The present paper describes a R&D study for water-tube boiler carried out in Kansai University and Hirakawa Guidam Co. Ltd. under the support of DME project from METI. The main problem arisen in DME use is a difficulty in an application of premixed flame owing to low ignition temperature and rather high burning velocity. Then the previously developed tube-nested combustor, i.e. water-tubes are installed in the empty furnace, becomes effective means to overcome such difficulty in realizing low-NOx combustion. This paper begins with a brief review of R&D study of the tube-nested combustor specifically designed for city gas. Then further development for DME-fired water-tube boiler is described.

scholarly journals Flammability and Propagation Dynamics of Planar Freely Propagating Dimethyl Ether Premixed Flame

ACS Omega ◽  
2020 ◽  
Vol 5 (19) ◽  
pp. 10965-10976 ◽  
Author(s):  
Congcong Liu ◽  
Yi Zhang ◽  
Deyang Xiong ◽  
Xiaomei Huang ◽  
Pengyuan Zhang ◽  
...  
Keyword(s):  
Dimethyl Ether ◽  
Premixed Flame ◽  
Propagation Dynamics

Laminar burning velocity of microalgae oil/RP-3 premixed flame at elevated initial temperature and pressure

Fuel ◽  
2022 ◽  
Vol 309 ◽  
pp. 122081
Author(s):  
Yu Liu ◽  
Wu Gu ◽  
Jinduo Wang ◽  
Hongan Ma ◽  
Nanhang Dong ◽  
...  
Keyword(s):  
Initial Temperature ◽  
Burning Velocity ◽  
Premixed Flame ◽  
Laminar Burning Velocity ◽  
Microalgae Oil ◽  
Temperature And Pressure

Effects of CH4 mixing on the laminar burning velocity and Markstein length of RP-3/air premixed flame

Fuel ◽  
2021 ◽  
Vol 289 ◽  
pp. 119761
Author(s):  
Yu Liu ◽  
Jinduo Wang ◽  
Wu Gu ◽  
Hongan Ma ◽  
Wen Zeng
Keyword(s):  
Burning Velocity ◽  
Premixed Flame ◽  
Laminar Burning Velocity ◽  
Markstein Length

A comparison of turbulent dimethyl ether and methane non-premixed flame structure

2013 ◽  
Vol 34 (1) ◽  
pp. 1447-1454 ◽  
Author(s):  
Kathryn N. Gabet ◽  
Han Shen ◽  
Randy A. Patton ◽  
Frederik Fuest ◽  
Jeffrey A. Sutton
Keyword(s):  
Dimethyl Ether ◽  
Flame Structure ◽  
Premixed Flame

Analysis of Nitrogen Oxides Formation in CH4/Air Laminar Premixed Flame

2013 ◽  
Vol 750-752 ◽  
pp. 1734-1737
Author(s):  
Jun Xia Zhang ◽  
Bing Biao Yang
Keyword(s):  
Nitrogen Oxides ◽  
Turbulent Diffusion ◽  
Mass Fraction ◽  
Burning Velocity ◽  
Flame Temperature ◽  
Premixed Flame ◽  
Model Parameters ◽  
Turbulent Diffusion Flame ◽  
Chemical Reaction Kinetics ◽  
Combustion Processes

Many combustion processes seriously pollute the environment because of producing nitrogen oxides emission, which abstracts wide attention from researchers. How to reduce nitrogen oxides emission is important to protect the environment. At the present work, a reduction mechanism based on a detailed chemical reaction kinetics mechanism, Gri_Mech3.0 was adopted to analyze nitrogen oxides formation in a CH4/air laminar premixed and turbulent diffusion flames, a two dimensional turbulent diffusion flame was simulated with the EDC model. Parameters were obtained, including flame temperature, burning velocity and mass fraction of nitrogen oxides. The results of laminar premixed flame show that nitrogen oxides emission mainly comes from the thermal and prompt NO mechanisms. A large amount of free radicals O, H and OH produced by combustion processes provide reactants for the reactions of nitrogen oxides formation. Mole fraction of nitrogen oxides increases with the increasing of both flame temperature and chemical equivalence ratios. By contrast, there is a lower mass fraction of nitrogen oxides formation for the fuel-lean flame.

Application of the Geared Turbofan With Constant Volume Combustor on Short-Range Aircraft: A Feasibility Study

2009 ◽  
Author(s):  
Fernando Colmenares Quintero ◽  
Rob Brink ◽  
Stephen Ogaji ◽  
Pericles Pilidis ◽  
Juan Carlos Colmenares Quintero ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Short Range ◽  
Operating Cost ◽  
Constant Volume ◽  
Superior Performance ◽  
Wave Rotor ◽  
Environmental Aspects ◽  
Direct Operating Cost ◽  
Combustion Technology ◽  
Further Development

Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behaviour. Wave rotor combustion provides semi-constant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary Multidisciplinary Design Framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, acquisition cost of the engine is higher, but engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emissions requirements.

Analyses of Coal and Sewage Sludge Co-Combustion Using Coats-Redfern Model

2012 ◽  
Vol 518-523 ◽  
pp. 3271-3274
Author(s):  
Huan Li ◽  
Yang Yang Li ◽  
Yi Ying Jin
Keyword(s):  
Activation Energy ◽  
Ignition Temperature ◽  
Burning Velocity ◽  
Fire Behavior ◽  
Volatile Matter ◽  
Water Evaporation ◽  
Fixed Carbon ◽  
Carbon Combustion ◽  
Blend Fuel ◽  
Dried Sludge

The co-combustibility of coal and sludge was investigated with thermogravimetric analysis. The results show that the burning process of sludge can be divided into three phases: water evaporation, volatile matter volatilization and combustion, fixed carbon combustion and burning out. The ignition temperature of sludge is only 260 degree centigrade at the beginning of volatile matter combustion. The addition of wet sludge or dried sludge will reduce the burning velocity of coal, and also decrease the ignition temperature. However the blend of coal and sludge has not an obvious stage of the volatile matter volatilization and combustion. The activation energy of the sludge is lower than that of the coal. The addition of wet sludge or dried sludge will decrease the activation energy of the blend fuel, and improve the fire behavior. On the whole, the sludge addition has little influence on the combustion of the coal when the addition ratio is lower than 10%.

The Large Capacity Pulverized Coal Fired Utility Boiler and the Low NOx Combustion Technology Developments in China in Response to Environmental Challenges

2011 ◽  
Author(s):  
Hao Zhou ◽  
Guiyuan Mo ◽  
Kefa Cen
Keyword(s):  
High Efficiency ◽  
Catalytic Reduction ◽  
Pulverized Coal ◽  
Large Capacity ◽  
Environmental Challenges ◽  
Utility Boiler ◽  
Integrated Technology ◽  
Combustion Technology ◽  
Low Nox Combustion ◽  
Scr System

Large capacity pulverized coal fired utility boiler technology is in quick developments in China, hundreds of super critical boilers have been constructed in the last several years which can achieve high efficiency and low pollutants emissions. The different types of super critical boilers are introduced in this paper, they include the single-furnace with double fireball corner fired furnace, the wall fired furnace and the tower-type furnace. The low NOx combustion technologies have been widely used to face the environmental challenges. The low NOx technologies employed in pulverized-coal boilers consist of the combustion modification and post-combustion technology. The low NOx combustion modification technology includes the low NOx burner, close coupled over fire air (CCOFA) and separated over fire air (SOFA). The post-combustion technology consists of selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) technologies. Zhejiang University develops integrated low NOx technology, including the low NOx combustion system, SNCR system and SCR system. This integrated technology can reduce the NOx emissions to be lower than 50 mg/Nm3.

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