The Experts below are selected from a list of 98211 Experts worldwide ranked by ideXlab platform
Weiping Yan - One of the best experts on this subject based on the ideXlab platform.
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prediction of wall temperature and oxide Scale Thickness of ferritic martensitic steel superheater tubes
Applied Thermal Engineering, 2018Co-Authors: Li Sun, Weiping YanAbstract:Abstract Based on the thermal deviation theory and local energy and mass balance of the superheater tube, a new method of calculating tube wall temperature is proposed. The wall temperature distribution and the Thickness of oxide Scale of the superheater tubes of a supercritical boiler are estimated over the length of the steam flow path for different periods of service. This calculation of oxide Scales on the steam side takes into account ash deposits on the flue gas side. The results of oxide Scale Thickness of boiler superheater tubes for different exposure time are compared with field measurement data. There is a sudden increase in the wall temperature at the tube elbow (position N) because of high gas temperature and high heat transfer coefficient. The distribution of the gas temperature field along the height of the heating surface has a great influence on the final wall temperature calculation results.
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Prediction of wall temperature and oxide Scale Thickness of ferritic–martensitic steel superheater tubes
Applied Thermal Engineering, 2018Co-Authors: Li Sun, Weiping YanAbstract:Abstract Based on the thermal deviation theory and local energy and mass balance of the superheater tube, a new method of calculating tube wall temperature is proposed. The wall temperature distribution and the Thickness of oxide Scale of the superheater tubes of a supercritical boiler are estimated over the length of the steam flow path for different periods of service. This calculation of oxide Scales on the steam side takes into account ash deposits on the flue gas side. The results of oxide Scale Thickness of boiler superheater tubes for different exposure time are compared with field measurement data. There is a sudden increase in the wall temperature at the tube elbow (position N) because of high gas temperature and high heat transfer coefficient. The distribution of the gas temperature field along the height of the heating surface has a great influence on the final wall temperature calculation results.
Li Sun - One of the best experts on this subject based on the ideXlab platform.
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prediction of wall temperature and oxide Scale Thickness of ferritic martensitic steel superheater tubes
Applied Thermal Engineering, 2018Co-Authors: Li Sun, Weiping YanAbstract:Abstract Based on the thermal deviation theory and local energy and mass balance of the superheater tube, a new method of calculating tube wall temperature is proposed. The wall temperature distribution and the Thickness of oxide Scale of the superheater tubes of a supercritical boiler are estimated over the length of the steam flow path for different periods of service. This calculation of oxide Scales on the steam side takes into account ash deposits on the flue gas side. The results of oxide Scale Thickness of boiler superheater tubes for different exposure time are compared with field measurement data. There is a sudden increase in the wall temperature at the tube elbow (position N) because of high gas temperature and high heat transfer coefficient. The distribution of the gas temperature field along the height of the heating surface has a great influence on the final wall temperature calculation results.
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Prediction of wall temperature and oxide Scale Thickness of ferritic–martensitic steel superheater tubes
Applied Thermal Engineering, 2018Co-Authors: Li Sun, Weiping YanAbstract:Abstract Based on the thermal deviation theory and local energy and mass balance of the superheater tube, a new method of calculating tube wall temperature is proposed. The wall temperature distribution and the Thickness of oxide Scale of the superheater tubes of a supercritical boiler are estimated over the length of the steam flow path for different periods of service. This calculation of oxide Scales on the steam side takes into account ash deposits on the flue gas side. The results of oxide Scale Thickness of boiler superheater tubes for different exposure time are compared with field measurement data. There is a sudden increase in the wall temperature at the tube elbow (position N) because of high gas temperature and high heat transfer coefficient. The distribution of the gas temperature field along the height of the heating surface has a great influence on the final wall temperature calculation results.
Rajarathinam Parthasarathy - One of the best experts on this subject based on the ideXlab platform.
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Scale formation on the wall of a mechanically stirred vessel experimental assessment and interpretation using computational fluid dynamics
Aiche Journal, 2018Co-Authors: Meysam Davoody, Lachlan Graham, Graeme Lane, Srinivasan Madapusi, Rajarathinam ParthasarathyAbstract:Accelerated growth of Scale was studied in a baffled agitated reactor, which could be disassembled into nine sections, allowing quantitative determination of Scale Thickness. A coordinate measuring machine was used to determine the Scale Thickness on individual wall segments. The growth pattern of the Scale was found to be nonuniform due to the variation of fluid velocity near the wall at various heights. Computational fluid dynamics (CFD) simulation showed that fluid flow is time-dependent and has two distinct flow zones, one involving recirculation through the impeller in the lower part of the vessel and the other involving lower velocities due to the flow separation at the wall in the upper part. CFD simulation also showed the presence of macroinstabilities, which manifest as asymmetrical and chaotic flow structures with relatively long-time Scales. Scale growth is found to be prominent in regions where the fluid velocity and wall shear stresses are low.
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Scale formation on the wall of a mechanically stirred vessel—experimental assessment and interpretation using computational fluid dynamics
AIChE Journal, 2018Co-Authors: Meysam Davoody, Lachlan Graham, Graeme Lane, Srinivasan Madapusi, Rajarathinam ParthasarathyAbstract:Accelerated growth of Scale was studied in a baffled agitated reactor, which could be disassembled into nine sections, allowing quantitative determination of Scale Thickness. A coordinate measuring machine was used to determine the Scale Thickness on individual wall segments. The growth pattern of the Scale was found to be nonuniform due to the variation of fluid velocity near the wall at various heights. Computational fluid dynamics (CFD) simulation showed that fluid flow is time-dependent and has two distinct flow zones, one involving recirculation through the impeller in the lower part of the vessel and the other involving lower velocities due to the flow separation at the wall in the upper part. CFD simulation also showed the presence of macroinstabilities, which manifest as asymmetrical and chaotic flow structures with relatively long-time Scales. Scale growth is found to be prominent in regions where the fluid velocity and wall shear stresses are low.
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A Novel Approach To Quantify Scale Thickness and Distribution in Stirred Vessels
Industrial & Engineering Chemistry Research, 2017Co-Authors: Meysam Davoody, Lachlan Graham, Inju Youn, Abdul Aziz Abdul Raman, Rajarathinam ParthasarathyAbstract:A novel approach is proposed for the numerical evaluation of Scale Thickness and its distribution in a mixing tank. While a majority of the available literature on the Scale build-up is focusing on the applications of chemical anti-scalants, few works have been devoted to preventing Scale formation through a proper design and operation of stirred vessels. The methodology proposed in the current study consists of two major phases: 1) identifying an accelerated process to grow Scales on the walls of a laboratory reactor and 2) analysing the grown Scale physically. These objectives were achieved through the fabrication of a reactor that could be disassembled and scanning the reactor’s surface using a coordinate measuring machine (CMM). The proposed approach was used to study the effects of liquid flow velocity and experiment duration on the pattern of the Scale formed qualitatively and quantitatively.
D.s. Citrin - One of the best experts on this subject based on the ideXlab platform.
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Structural characterization of mill-Scale on production steel using terahertz pulse imaging in reflective geometry
2020Co-Authors: Min Zhai, A. Locquet, Cyrielle Roquelet, D.s. CitrinAbstract:Terahertz pulsed imaging was employed to characterize the mill Scale Thickness on production steel, validating this practical application of terahertz technology in a production environment.
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Nondestructive measurement of mill-Scale Thickness on steel by terahertz time-of-flight tomography
Surface and Coatings Technology, 2020Co-Authors: Min Zhai, Cyrielle Roquelet, Alexandre Locquet, Patrice Alexandre, Laurence Dahéron, D.s. CitrinAbstract:We measure in a nondestructive and noncontact fashion the Thicknesses of three Scale films with Thicknesses 28.5 ± 1.4 μm, 13.4± 0.9 μm, and 5.1 ± 0.3 μm on steel substrates employing terahertz time-of-flight tomography combined with advanced signal-processing techniques. Wüstite is the dominant phase in the Scale films, though magnetite and hematite are also present. Because wüstite is electrically insulating, the incident terahertz electromagnetic pulses largely penetrate into the Scale film; however, the pulses are entirely reflected by the underlying electrically conductive steel substrate. Because the film layers are thin, in some cases optically thin, the distinct pulses reflected at the air/Scale and Scale/steel interfaces overlap in time and thus are not visually evident in the reflected terahertz signal, necessitating the use of deconvolution techniques to recover the sample structure. We compare the merits of three deconvolution techniques, one unsuccessful (frequency-wavelet domain deconvolution) and two successful (sparse deconvolution and autoregressive extrapolation), to characterize the Thicknesses of these Scale films.
Meysam Davoody - One of the best experts on this subject based on the ideXlab platform.
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Scale formation on the wall of a mechanically stirred vessel experimental assessment and interpretation using computational fluid dynamics
Aiche Journal, 2018Co-Authors: Meysam Davoody, Lachlan Graham, Graeme Lane, Srinivasan Madapusi, Rajarathinam ParthasarathyAbstract:Accelerated growth of Scale was studied in a baffled agitated reactor, which could be disassembled into nine sections, allowing quantitative determination of Scale Thickness. A coordinate measuring machine was used to determine the Scale Thickness on individual wall segments. The growth pattern of the Scale was found to be nonuniform due to the variation of fluid velocity near the wall at various heights. Computational fluid dynamics (CFD) simulation showed that fluid flow is time-dependent and has two distinct flow zones, one involving recirculation through the impeller in the lower part of the vessel and the other involving lower velocities due to the flow separation at the wall in the upper part. CFD simulation also showed the presence of macroinstabilities, which manifest as asymmetrical and chaotic flow structures with relatively long-time Scales. Scale growth is found to be prominent in regions where the fluid velocity and wall shear stresses are low.
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Scale formation on the wall of a mechanically stirred vessel—experimental assessment and interpretation using computational fluid dynamics
AIChE Journal, 2018Co-Authors: Meysam Davoody, Lachlan Graham, Graeme Lane, Srinivasan Madapusi, Rajarathinam ParthasarathyAbstract:Accelerated growth of Scale was studied in a baffled agitated reactor, which could be disassembled into nine sections, allowing quantitative determination of Scale Thickness. A coordinate measuring machine was used to determine the Scale Thickness on individual wall segments. The growth pattern of the Scale was found to be nonuniform due to the variation of fluid velocity near the wall at various heights. Computational fluid dynamics (CFD) simulation showed that fluid flow is time-dependent and has two distinct flow zones, one involving recirculation through the impeller in the lower part of the vessel and the other involving lower velocities due to the flow separation at the wall in the upper part. CFD simulation also showed the presence of macroinstabilities, which manifest as asymmetrical and chaotic flow structures with relatively long-time Scales. Scale growth is found to be prominent in regions where the fluid velocity and wall shear stresses are low.
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A Novel Approach To Quantify Scale Thickness and Distribution in Stirred Vessels
Industrial & Engineering Chemistry Research, 2017Co-Authors: Meysam Davoody, Lachlan Graham, Inju Youn, Abdul Aziz Abdul Raman, Rajarathinam ParthasarathyAbstract:A novel approach is proposed for the numerical evaluation of Scale Thickness and its distribution in a mixing tank. While a majority of the available literature on the Scale build-up is focusing on the applications of chemical anti-scalants, few works have been devoted to preventing Scale formation through a proper design and operation of stirred vessels. The methodology proposed in the current study consists of two major phases: 1) identifying an accelerated process to grow Scales on the walls of a laboratory reactor and 2) analysing the grown Scale physically. These objectives were achieved through the fabrication of a reactor that could be disassembled and scanning the reactor’s surface using a coordinate measuring machine (CMM). The proposed approach was used to study the effects of liquid flow velocity and experiment duration on the pattern of the Scale formed qualitatively and quantitatively.
