The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Poveda S Martinez - One of the best experts on this subject based on the ideXlab platform.
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a comparative study of high temperature erosion wear of plasma sprayed nicrbsife and wc nicrbsife coatings under simulated coal Fired Boiler conditions
Tribology International, 2001Co-Authors: Higuera V Hidalgo, Carriles A Menendez, F Belzunce J Varela, Poveda S MartinezAbstract:Abstract A comparative study was carried out of the behaviour of plasma sprayed NiCrBSiFe and WC–NiCrBSiFe alloys subjected to conditions which simulate a post-combustion gas atmosphere from a coal-Fired Boiler combustor. The study first evaluates the effects of thermal exposure at high temperatures on the microstructure of the coatings and on the adherence between substrate (austenitic stainless steel) and coatings. The oxidation rates of these coatings in atmospheres with 3–3.5% of free oxygen at 773 and 1073 K were then evaluated. The effect of WC on the low-velocity corrosion–erosion behaviour produced by the impact of fly ashes in the gas stream at high temperatures (773 and 1073 K) was assessed under impact angles of 30° and 90°. Finally, the eroded surfaces were analysed using scanning electron microscopy in order to characterize the ash embedment phenomena and the operating erosive micromechanisms.
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high temperature erosion wear of flame and plasma sprayed nickel chromium coatings under simulated coal Fired Boiler atmospheres
Wear, 2001Co-Authors: Higuera V Hidalgo, Belzunce J Varela, Carriles A Menendez, Poveda S MartinezAbstract:Abstract This study concerns the behaviour of plasma and flame sprayed modified nickel–chromium alloy (with small aluminium and titanium additions) subjected to the action of simulated post-combustion gases from a coal-Fired Boiler combustor. The study first evaluates the effects of thermal exposure at high temperature on the adherence between the substrate (austenitic stainless steel) and coatings. Then, the oxidation rates of these coatings in atmospheres with 3–3.5% of free oxygen at 500 and 800°C (773 and 1073 K) were evaluated. The low velocity corrosion–erosion behaviour produced by the impact of fly ashes in the gas stream at high temperatures (773 and 1073 K) was also evaluated under impact angles of 30 and 90°. Finally, the eroded surfaces were analysed using scanning electron microscopy in order to characterise the ash embedment phenomena and the operating erosive micromechanisms.
Huaichun Zhou - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of multifuel combustion in a 200 mw tangentially Fired utility Boiler
Energy & Fuels, 2012Co-Authors: Qingyan Fang, Amir A B Musa, Yan Wei, Zixue Luo, Huaichun ZhouAbstract:A computational fluid dynamics (CFD) model of a 200 MW multifuel tangentially Fired Boiler has been developed using Fluent 6.3.26, which is able to model the three-fuel combustion system of coal, b...
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Estimation of radiative properties and temperature distributions in coal-Fired Boiler furnaces by a portable image processing system
Experimental Thermal and Fluid Science, 2011Co-Authors: Wenhao Li, Huaichun ZhouAbstract:Abstract This paper presented an experimental investigation on the estimation of radiative properties and temperature distributions in a 670 t/h coal-Fired Boiler furnace by a portable imaging processing system. The portable system has been calibrated by a blackbody furnace. Flame temperatures and emissivities were measured by the portable system and equivalent blackbody temperatures were deduced. Comparing the equivalent blackbody temperatures measured by the portable system and the infrared pyrometer, the relative difference is less than 4%. The reconstructed pseudo-instantaneous 2-D temperature distributions in two cross-sections can disclose the combustion status inside the furnace. The measured radiative properties of particles in the furnace proved there is significant scattering in coal-Fired Boiler furnaces and it can provide useful information for the calculation of radiative heat transfer and numerical simulation of combustion in coal-Fired Boiler furnaces. The preliminary experimental results show this technology will be helpful for the combustion diagnosis in coal-Fired Boiler furnaces.
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measurements of the flame emissivity and radiative properties of particulate medium in pulverized coal Fired Boiler furnaces by image processing of visible radiation
Proceedings of the Combustion Institute, 2007Co-Authors: Huaichun Zhou, Pengfeng Yu, Zhiwei JiangAbstract:Abstract Due to the complicated processes for coal particles burning in industrial furnaces, their radiative properties, such as the absorption and scattering coefficients, which are essential to make reliable calculation of radiative transfer in combustion computation, are hard to be given exactly by the existing methods. In this paper, multiple color image detectors were used to capture approximately red, green, and blue monochromatic radiative intensity images in the visible wavelength region, and the flame emissivity and the radiative properties of the particulate media in three pulverized-coal-Fired Boiler furnaces were got from the flame images. It was shown that as the load increased, the flame emissivity and the radiative properties increased too; these radiative parameters had the largest values near the burner zone, and decreased along the combustion process. Compared with the combustion medium with a low-volatile anthracite coal burning in a 670 t/h Boiler, the emissivity and the absorption coefficient of the medium with a high-volatile bituminous coal burning in a 1025 t/h Boiler were smaller near the outlet zone, but were larger near the burner zone of the furnace, due to the significant contribution of soot to the radiation. This work will be of practical importance in modeling and calculating the radiative heat transfer in combustion processes, and improving the technology for in situ, multi-dimensional visualization of large-scale combustion processes in coal-Fired furnaces of power plants.
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experimental investigations on visualization of three dimensional temperature distributions in a large scale pulverized coal Fired Boiler furnace
Proceedings of the Combustion Institute, 2005Co-Authors: Huaichun Zhou, Zhiwei Jiang, Chun Lou, Qiang Cheng, Benyuan Huang, Zhenlin PeiAbstract:Abstract By using a novel flame image processing technique, the 3-D temperature distributions of combustion in the pulverized-coal-Fired Boiler furnace of a 200 MW power generation unit were visualized experimentally. With the assumption of gray radiation, multiple color flame image detectors were used to capture approximately monochromatic radiation intensity images under the visible wavelengths of red (R), green (G), and blue (B), and a blackbody furnace was used to calibrate the color images. A way to calculate the radiation intensity using the Monte Carlo method was used to establish the relationship between the radiation flame images and the 3-D temperature distribution inside the furnace, given the radiative parameters such as the absorption and scattering coefficients of the combustion medium. A modified Tikhonov regularization method was used to reconstruct the 3-D temperature distribution from the 2-D flame temperature images transformed from the color flame images. Eight flame image detectors were mounted close to the four corners in four layers in different heights in the furnace, the 3-D temperature distribution in 1200 discrete meshes in 12 layers along the height of the furnace was reconstructed from the eight flame images, and the visualization result was updated within 5 s. The errors between some local temperatures visualized by the present system with those measured by a suction thermocouple were within ±5%, showing applicability of the method. On-line monitoring results demonstrated that the average temperature inside the furnace changed directly proportionally with the load of the unit. The preliminary results show that this technology will be useful for the combustion diagnosis and control in coal-Fired power generation plants.
Higuera V Hidalgo - One of the best experts on this subject based on the ideXlab platform.
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a comparative study of high temperature erosion wear of plasma sprayed nicrbsife and wc nicrbsife coatings under simulated coal Fired Boiler conditions
Tribology International, 2001Co-Authors: Higuera V Hidalgo, Carriles A Menendez, F Belzunce J Varela, Poveda S MartinezAbstract:Abstract A comparative study was carried out of the behaviour of plasma sprayed NiCrBSiFe and WC–NiCrBSiFe alloys subjected to conditions which simulate a post-combustion gas atmosphere from a coal-Fired Boiler combustor. The study first evaluates the effects of thermal exposure at high temperatures on the microstructure of the coatings and on the adherence between substrate (austenitic stainless steel) and coatings. The oxidation rates of these coatings in atmospheres with 3–3.5% of free oxygen at 773 and 1073 K were then evaluated. The effect of WC on the low-velocity corrosion–erosion behaviour produced by the impact of fly ashes in the gas stream at high temperatures (773 and 1073 K) was assessed under impact angles of 30° and 90°. Finally, the eroded surfaces were analysed using scanning electron microscopy in order to characterize the ash embedment phenomena and the operating erosive micromechanisms.
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high temperature erosion wear of flame and plasma sprayed nickel chromium coatings under simulated coal Fired Boiler atmospheres
Wear, 2001Co-Authors: Higuera V Hidalgo, Belzunce J Varela, Carriles A Menendez, Poveda S MartinezAbstract:Abstract This study concerns the behaviour of plasma and flame sprayed modified nickel–chromium alloy (with small aluminium and titanium additions) subjected to the action of simulated post-combustion gases from a coal-Fired Boiler combustor. The study first evaluates the effects of thermal exposure at high temperature on the adherence between the substrate (austenitic stainless steel) and coatings. Then, the oxidation rates of these coatings in atmospheres with 3–3.5% of free oxygen at 500 and 800°C (773 and 1073 K) were evaluated. The low velocity corrosion–erosion behaviour produced by the impact of fly ashes in the gas stream at high temperatures (773 and 1073 K) was also evaluated under impact angles of 30 and 90°. Finally, the eroded surfaces were analysed using scanning electron microscopy in order to characterise the ash embedment phenomena and the operating erosive micromechanisms.
Barry N Liebowitz - One of the best experts on this subject based on the ideXlab platform.
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optimization of coal Fired Boiler scrs based on modified support vector machine models and genetic algorithms
Fuel, 2009Co-Authors: Carlos E Romero, Zheng Yao, Eugenio Schuster, Robert L Morey, Barry N LiebowitzAbstract:An integrated combustion optimization approach is presented for the combined considering the trade offs in optimization of coal-Fired Boiler and selective catalyst reaction (SCR) system, to balance the unit thermal efficiency, SCR reagent consumption and NOx emissions. Field tests were performed at a 160 MW coal-Fired unit to investigate the relationships between process controllable variables, and optimization targets and constraints. Based on the test data, a modified on-line support vector regression model was proposed for characteristic function approximation, in which the model parameters can be continuously adapted for changes in coal quality and other conditions of plant equipment. The optimization scheme was implemented by a genetic algorithm in two stages. Firstly, the multi-objective combustion optimization problem was solved to achieve an optimal Pareto front, which contains optimal solutions for lowest unit heat rate and lowest NOx emissions. Secondly, best operating settings for the Boiler, and SCR system and air preheater were obtained for lowest operating cost under the constraints of NOx emissions limit and air preheater ammonium bisulfate deposition depth.
Carriles A Menendez - One of the best experts on this subject based on the ideXlab platform.
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a comparative study of high temperature erosion wear of plasma sprayed nicrbsife and wc nicrbsife coatings under simulated coal Fired Boiler conditions
Tribology International, 2001Co-Authors: Higuera V Hidalgo, Carriles A Menendez, F Belzunce J Varela, Poveda S MartinezAbstract:Abstract A comparative study was carried out of the behaviour of plasma sprayed NiCrBSiFe and WC–NiCrBSiFe alloys subjected to conditions which simulate a post-combustion gas atmosphere from a coal-Fired Boiler combustor. The study first evaluates the effects of thermal exposure at high temperatures on the microstructure of the coatings and on the adherence between substrate (austenitic stainless steel) and coatings. The oxidation rates of these coatings in atmospheres with 3–3.5% of free oxygen at 773 and 1073 K were then evaluated. The effect of WC on the low-velocity corrosion–erosion behaviour produced by the impact of fly ashes in the gas stream at high temperatures (773 and 1073 K) was assessed under impact angles of 30° and 90°. Finally, the eroded surfaces were analysed using scanning electron microscopy in order to characterize the ash embedment phenomena and the operating erosive micromechanisms.
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high temperature erosion wear of flame and plasma sprayed nickel chromium coatings under simulated coal Fired Boiler atmospheres
Wear, 2001Co-Authors: Higuera V Hidalgo, Belzunce J Varela, Carriles A Menendez, Poveda S MartinezAbstract:Abstract This study concerns the behaviour of plasma and flame sprayed modified nickel–chromium alloy (with small aluminium and titanium additions) subjected to the action of simulated post-combustion gases from a coal-Fired Boiler combustor. The study first evaluates the effects of thermal exposure at high temperature on the adherence between the substrate (austenitic stainless steel) and coatings. Then, the oxidation rates of these coatings in atmospheres with 3–3.5% of free oxygen at 500 and 800°C (773 and 1073 K) were evaluated. The low velocity corrosion–erosion behaviour produced by the impact of fly ashes in the gas stream at high temperatures (773 and 1073 K) was also evaluated under impact angles of 30 and 90°. Finally, the eroded surfaces were analysed using scanning electron microscopy in order to characterise the ash embedment phenomena and the operating erosive micromechanisms.