Spectroscopic Observation of Chemical Species From High-Temperature Air Pulverized Coal Combustion

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Nelfa Desmira ◽  
Takuya Nagasaka ◽  
Kimihito Narukawa ◽  
Akira Ishikawa ◽  
Kuniyuki Kitagawa ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Flame Temperature ◽  
Chemical Species ◽  
Emission Spectra ◽  
Video Camera ◽  
Spectroscopic Observation ◽  
Pulverized Coal ◽  
In Situ Monitoring ◽  
Lean Combustion

In situ monitoring of chemical species from the combustion pulverized coal in high-temperature air is examined using several different spectroscopic diagnostic at different equivalence ratios. Two-dimensional (2D) distributions of flame temperature were obtained using a thermal video camera. The experimental results showed the temperatures to range from low to 1400 °C under various conditions of fuel-lean, stoichiometric, and fuel-rich. The highest temperature and flame stability were obtained under fuel-lean combustion condition. The chemical species generated from within the combustion zone were analyzed from the spontaneous emission spectra of the flame in the Ultraviolet–visible (UV-Vis) range. The spatial distribution of NO, OH, and CN were identified from the spectra. The 2D distribution of emission intensity visualized and recorded for NO, OH, and CN revealed high-temperatures close to the root of the flame that rapidly dispersed radially outward to provide very high temperatures over a much larger volume at further downstream locations of the flame.

Hydroxyl and Nitric Oxide Distribution in Waste Rice Bran Biofuel-Octanol Flames

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Nelfa Desmira ◽  
Kuniyuki Kitagawa ◽  
Ashwani K. Gupta
Keyword(s):  
Nitric Oxide ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Saturated Fatty Acids ◽  
Flame Temperature ◽  
Chemical Species ◽  
Emission Spectra ◽  
Fuel Mixture ◽  
Video Camera ◽  
Two Dimensional

Two-dimensional (2-D) visualization of hydroxyl (OH) radical in combustion of biofuel made of waste rice bran oil (called W) mixed with octanol (called O) at different mixture ratios were examined in a laboratory scale facility using planar laser-induced fluorescence (PLIF) diagnostics. Rice bran oil has a composition similar to that of peanut oil, with 38% monounsaturated, 37% polyunsaturated, and 25% saturated fatty acids. The ratio of this biofuel to octanol fuel examined was W90/O10, W75/O25, and W60/O40. The chemical species generated from within the combustion zone were analyzed from the spontaneous emission spectra of the flame in the ultraviolet to visible (Uv-Vis) range. The spatial distribution of Nitric Oxide (NO) and OH, denoted as OH*, were identified from the spectra. Two-dimensional (2-D) distributions of flame temperature were obtained using a thermal video camera. The experimental results showed the temperatures to range from 600 °C to 1400 °C. The highest temperature was obtained using W60/O40 waste/octanol fuel mixture. A practical burner commonly used in Indonesia, called semawar, that have a built-in preheating system was used for the combustion of biofuels.

scholarly journals Performance of Pulverized Coal Combustion under High Temperature Air Diluted by Steam

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Mohsen Saffari Pour ◽  
Yang Weihong
Keyword(s):  
High Temperature ◽  
Coal Combustion ◽  
Fluid Dynamic ◽  
Flame Temperature ◽  
Experimental Tests ◽  
Injection Rate ◽  
Pulverized Coal ◽  
Injection Velocity ◽  
Pulverized Coal Combustion ◽  
Injection Speed

The high temperature air combustion (HiTAC) is an advanced promising technology for heat recovery, energy saving, and stability improvement of flame. Computational fluid dynamic (CFD) is known as an applied tool to execute HiTAC modeling. In this paper, performances of pulverized coal combustion under the high preheated and oxygen deficient air are studied by both experimental and numerical methodology. The experimental facilities have been accomplished in a HiTAC chamber with coal injection velocity that ranges from 10 to 40 m/s. In order to achieve different preheated temperatures, the combustion air in such system is diluted by variable steam percentages from 0 to 44%. Results of mathematical simulation and experimental tests present convincible agreement through whole region. It is concluded that NOX emission is reduced by increasing the steam percentage in the oxidizer due to decreasing the flame temperature. Besides, graphical contours show that by adding more steam to oxidizer composition, the oxygen concentration decreased. Additionally, results show that when the injection speed of fuel is increased, NOX emission is also increased, and when the injection rate of preheated air is increased, NOX emission shows decreasing trend. Further contribution in future is needed to investigate the performance of such technologies.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

CARLSON ALLOY C601

Alloy Digest ◽  
1994 ◽  
Vol 43 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Stress Corrosion ◽  
Tensile Properties ◽  
High Temperatures ◽  
Stress Corrosion Cracking ◽  
Heat Treating ◽  
Resistance To Stress ◽  
Extended Exposure ◽  
Sulfur Containing

Abstract Carlson Alloy C601 is characterized by high tensile, yield and creep-rupture strengths for high temperature service. The alloy is not embrittled by extended exposure to high temperatures and has excellent resistance to stress-corrosion cracking, to carburizing, nitriding and sulfur containing environments. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on forming, heat treating, machining, and joining. Filing Code: Ni-458. Producer or source: G.O. Carlson Inc.

INCOTHERM TD

Alloy Digest ◽  
2005 ◽  
Vol 54 (11) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Rare Earths ◽  
Temperature Performance

Abstract Incotherm TD is a thermocouple-sheathing alloy with elements of silicon and rare earths to enhance oxidation resistance at high temperatures. This datasheet provides information on composition, physical properties, and tensile properties as well as deformation. It also includes information on high temperature performance and corrosion resistance as well as forming. Filing Code: Ni-628. Producer or source: Special Metals Corporation.

HASTELLOY ALLOY X

Alloy Digest ◽  
1954 ◽  
Vol 3 (12) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Heat Treating ◽  
Operating Conditions ◽  
Molybdenum Alloy ◽  
High Temperature Strength ◽  
Nickel Chromium

Abstract HASTELLOY Alloy X is a nickel-chromium-iron-molybdenum alloy recommended for high-temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on forming, heat treating, and machining. Filing Code: Ni-14. Producer or source: Haynes Stellite Company.

KUBOTA ALLOY HT

Alloy Digest ◽  
2011 ◽  
Vol 60 (11) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Nickel Alloy ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Temperature Performance ◽  
Iron Chromium

Abstract Kubota Alloy HT is an iron-chromium-nickel alloy that has both strength and oxidation resistance at high temperatures. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on high temperature performance as well as casting and joining. Filing Code: SS-1108. Producer or source: Kubota Metal Corporation, Fahramet Division.

KENTANIUM K138A

Alloy Digest ◽  
1964 ◽  
Vol 13 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
High Temperature ◽  
Titanium Carbide ◽  
Physical Properties ◽  
Engineering Design ◽  
High Temperatures

Abstract Kentanium K138-A is a high temperature titanium carbide that greatly widens the scope of the engineering design where conditions of intermittent or continuous high temperatures in oxidizing atmospheres are combined with abrasion, and compressive or tensile loads. This datasheet provides information on composition, physical properties, hardness, elasticity, and compressive strength as well as fracture toughness, creep, and fatigue. It also includes information on machining and joining. Filing Code: Ti-40. Producer or source: Kennametal Inc..

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