The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Piotr Duda - One of the best experts on this subject based on the ideXlab platform.
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Shape and operation optimization of a thick-walled Power Boiler component
MATEC Web of Conferences, 2018Co-Authors: Piotr Duda, Mirosław MrzygłódAbstract:The aim of this article is the proposition of a two-stage optimization of Power Boiler components subjected to transient thermo-mechanical loads. As the basis of transient load regime, the TRD 301 regulations are used. In the first stage of an investigation, the genetic algorithms are used to determine the optimal shape of the structure. As optimization constraints, the maximum total stresses in the whole cycle are assumed. In the next stage, the method for the start-up and shut-down operation optimization is shown. The problem is defined to minimize the time of start-up and shut-down processes with allowable stress constraints according to TRD regulations. These new methods are of high practical significance and can be implemented throughout the industry, wherever heating and cooling processes take place. The obtained optimization results translate directly into the Power unit energy effectiveness because the shut-down and start-up losses are reduced.
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Shape optimization of a thick-walled Power Boiler component
E3S Web of Conferences, 2017Co-Authors: Piotr Duda, Mirosław MrzygłódAbstract:This paper presents a methodology and successful application of structural optimization of a T-pipe under transient thermal and mechanical loads. In order to find the optimal shape of a thick-walled Power Boiler component, a parametric FE model and the evolutionary algorithm (EA) are applied. The Power Boiler start-up and shutdown curves are based on the TRD 301 guidelines. Maximum total stresses are assumed as optimization constraints. The obtained geometry is by about 18.6% lighter than the original one due to thinning of the walls. Maximum tensile and compressive stresses in the modified geometry are smaller than in the original one during the whole cycle. Additionally, lower total stress values are recorded during heating and cooling processes. Therefore, these transient processes can be accelerated and the shutdown and start-up losses can be reduced.
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inverse estimation of the transient state stress distribution in the Power Boiler pressure components
International Journal of Mechanical Sciences, 2016Co-Authors: Piotr DudaAbstract:Abstract The aim of this work is to present an inverse method of stress estimation in pressure components of Power Boilers. The proposed algorithm reconstructs the time- and space-dependent temperature, strain and stress distribution in some cross sections of thick-walled cylindrical elements without information concerning the thermal boundary condition on the inner surface. The solution is possible thanks to “measured” temperature histories in easily accessible points located on the component outer surface. In order to stabilize the solution, the data are smoothed out using digital filters based on local polynomial approximation. The material properties of the Power Boiler elements are assumed as temperature-dependent and the inverse problem is solved iteratively. The proposed method is verified numerically and experimentally in a steam header located on a laboratory stand in the Cracow University of Technology. The presented method may be used in monitoring systems of both conventional and nuclear Power plants.
Masaaki Igarashi - One of the best experts on this subject based on the ideXlab platform.
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10-Year Experience With T23(2.25Cr-1.6W) and T122(12Cr-0.4Mo-2W) in a Power Boiler
Journal of Pressure Vessel Technology, 2004Co-Authors: Nobuyoshi Komai, Fujimitsu Masuyama, Masaaki IgarashiAbstract:Tungsten strengthened ferritic steels, 2.25Cr-1.6W-V-Nb and 12Cr-0.4Mo-2W-V-Nb-Cu have been developed and approved by the ASME Boiler and Pressure Vessels Code Committee for use in Section I construction, designated as T23 and T122, respectively. A field exposure test installing both steel tubes in service along with comparative materials in the tertiary superheater and secondary reheater of a 156 MW utility Power Boiler has been conducted since April 1993. The tubes were removed to confirm their material properties and corrosion/steam oxidation behaviors after 1-year, 3-year, 6-year, and 10-year periods of service. The tensile and creep rupture strengths of both steels showed no remarkable change during service. Examination of steam oxidation scale on the inner surface of the tubes indicated that the scale growth rate of T122 was extremely small following 1-year service. The growth rate and morphology of steam oxidation scale is discussed, as compared with conventional materials.
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10-Year Experience With T23(2.25Cr-1.6W) and T122(12Cr-0.4Mo-2W) in a Power Boiler
Experience With Creep-Strength Enhanced Ferritic Steels and New and Emerging Computational Methods, 2004Co-Authors: Nobuyoshi Komai, Fujimitsu Masuyama, S. Yamamoto, Masaaki IgarashiAbstract:Tungsten strengthened ferritic steels, 2.25Cr-1.6W-V-Nb and 12Cr-0.4Mo-2W-V-Nb-Cu have been developed and approved by the ASME Boiler and Pressure Vessels Code Committee for use in Section I construction, designated as T23 and T122 respectively. A field exposure test installing both steel tubes in service along with comparative materials in the tertiary superheater and secondary reheater of a 156MW utility Power Boiler has been conducted since April 1993. The tubes were removed to confirm their material properties and corrosion/steam oxidation behaviors after one-year, 3-year, 6-year and 10-year periods of service. The tensile and creep rupture strengths of both steels showed no remarkable change during service. Examination of steam oxidation scale on the inner surface of the tubes indicated that the scale growth rate of T122 was extremely small following one-year service. The growth rate and morphology of steam oxidation scale is discussed, as compared with conventional materials.Copyright © 2004 by ASME
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3-Year Experience with 2.25 Cr-1.6 W (HCM2S) and 12Cr-0.4Mo-2W (HCM12A) Steel Tubes in a Power Boiler.
JSME International Journal Series B, 1998Co-Authors: Fujimitsu Masuyama, Tomomitsu Yokoyama, Nobuyoshi Komai, S. Yamamoto, Kaori Miyata, Masaaki IgarashiAbstract:Both of the newly developed tungsten strengthened ferritic steels considered here, i.e., 2.25Cr-1.6W V Nb (HCM2S) steel and 12Cr-0.4Mo-2W-1Cu-V-Nb (HCM12A) steel, have the practical capability to be used for steam generator tubing due to their excellent fabricability and very high creep strength, These steels have already been approved by the ASME Boiler and Pressure Vessel Code Committee for use in Section I construction. A field service test putting these steel tubes in service along with comparative materials in the tertiary superheater and secondary reheater of a 156 MW utility Power Boiler has been conducted since April 1993, and the tubes were removed to confirm their material properties and corrosion/steam oxidation behaviors after one-year and 3 year periods of service. The investigation results showed that the practical performances of HCM2S and HCM12A steel tubes were good, demonstrating superior corrosion resistance and less material degradation than the comparative materials. This paper deals with the practical properties and examination results of these newly developed steels compared with conventional Boiler steels.
Mirosław Mrzygłód - One of the best experts on this subject based on the ideXlab platform.
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Shape and operation optimization of a thick-walled Power Boiler component
MATEC Web of Conferences, 2018Co-Authors: Piotr Duda, Mirosław MrzygłódAbstract:The aim of this article is the proposition of a two-stage optimization of Power Boiler components subjected to transient thermo-mechanical loads. As the basis of transient load regime, the TRD 301 regulations are used. In the first stage of an investigation, the genetic algorithms are used to determine the optimal shape of the structure. As optimization constraints, the maximum total stresses in the whole cycle are assumed. In the next stage, the method for the start-up and shut-down operation optimization is shown. The problem is defined to minimize the time of start-up and shut-down processes with allowable stress constraints according to TRD regulations. These new methods are of high practical significance and can be implemented throughout the industry, wherever heating and cooling processes take place. The obtained optimization results translate directly into the Power unit energy effectiveness because the shut-down and start-up losses are reduced.
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Shape optimization of a thick-walled Power Boiler component
E3S Web of Conferences, 2017Co-Authors: Piotr Duda, Mirosław MrzygłódAbstract:This paper presents a methodology and successful application of structural optimization of a T-pipe under transient thermal and mechanical loads. In order to find the optimal shape of a thick-walled Power Boiler component, a parametric FE model and the evolutionary algorithm (EA) are applied. The Power Boiler start-up and shutdown curves are based on the TRD 301 guidelines. Maximum total stresses are assumed as optimization constraints. The obtained geometry is by about 18.6% lighter than the original one due to thinning of the walls. Maximum tensile and compressive stresses in the modified geometry are smaller than in the original one during the whole cycle. Additionally, lower total stress values are recorded during heating and cooling processes. Therefore, these transient processes can be accelerated and the shutdown and start-up losses can be reduced.
Vic Uloth - One of the best experts on this subject based on the ideXlab platform.
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Dioxins formation in salt-laden Power Boilers: A mass balance
Chemosphere, 1998Co-Authors: C.e. Luthe, Ibrahim Karidio, Vic UlothAbstract:Abstract Stack dioxins emissions at a coastal pulp mill burning salt-laden wood waste in its Power Boiler, at typical steam production rates, were found to be 0.089 ng/m 3 (in terms of toxicity equivalents (TEQs)). These levels are well within the guideline of 0.5 ng/m 3 recommended for municipal solid waste incinerators by the Canadian Council of Ministers for Environment. Stack emissions accounted for less than 1 % of all dioxin TEQs generated by the Power Boiler. While some dioxins appear to have been generated within the particulate collection devices, the excellent TEQ removal efficiency of these units confirms their essential role in controlling stack dioxins emissions. The TEQ contribution from high temperature (>600°C) dioxins formation appears to have been minimal, less than 15% of the total. This suggests that in Power Boilers fuelled with salt-laden wood waste, dioxins formation occurs primarily at low temperatures. Consequently, temperature quenching could be relatively effective as a potential control strategy.
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Towards controlling dioxins emissions from Power Boilers fuelled with salt-laden wood waste
Chemosphere, 1997Co-Authors: C.e. Luthe, Ibrahim Karidio, Vic UlothAbstract:Abstract An evaluation of the dioxins emissions from a Power Boiler fuelled with salt-laden wood waste has provided insights on potential control technologies. Whereas a reduction in stack particulate levels does not preclude a corresponding reduction in dioxins emissions, good combustion conditions, in combination with an efficient secondary collection device for particulate removal, were found to offer effective control (stack emissions of 0.064 to 0.086 ng TEQ/m 3 ). Regarding minimization of dioxins formation at source, a preliminary assessment of the possible beneficial effect of an attenuated chlorine: sulphur ratio was encouraging. A more accurate assessment requires additional trials, preferably longer in duration, to eliminate any possible memory effects.
J. R. Kish - One of the best experts on this subject based on the ideXlab platform.
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Corrosion of High-Alloy Superheater Tubes in a Coastal Biomass Power Boiler
CORROSION, 2008Co-Authors: J. R. Kish, C. Reid, Douglas L. Singbeil, R. SeguinAbstract:Abstract Metallurgical examinations were conducted on a set of damaged high-alloy (Type 310H [UNS S31009] stainless steel and Alloy 625 [UNS N66250] weld overlay) superheater tubes removed from a coastal fluidized bed biomass Power Boiler, to better understand the degradation mode. Active oxidation (gas-solid reaction occurring underneath the chloride-containing fireside deposit) was found to be the mechanism responsible for the significant loss in tube wall thickness observed on damaged superheater tubes. There exists a complex, poorly-understood synergy between the critical factors that affect active oxidation, primarily tube temperature and the supply of reactants in the flue gas, namely, sodium chloride (NaCl), sulfur dioxide (SO2), and water vapor (H2O). Overall ranking in terms of increasing corrosion resistance to active oxidation follows the expected trend: T22 < SS310H < A625WO. Despite the favorable ranking, the Alloy 625 weld overlay can corrode by active oxidation at an appreciable rate (0.45 ...
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Corrosion of Bed Nozzle Alloys in a Wood-Waste Fluidized Bed Power Boiler
CORROSION, 2007Co-Authors: J. R. Kish, P. Eng, Douglas L. Singbeil, O. Posein, R. SeguinAbstract:Abstract A field test was conducted to identify a more corrosion-resistant material than Type 310H (UNS S31009) stainless steel, from which to fabricate bed nozzles for a fluidized bed Power Boiler that burns salt-laden wood-waste (hogged) fuel. Test nozzles fabricated from Type 310H stainless steel, Alloys 556 (UNS R30556), 59 (UNS N06059), HR160 (UNS N12160), and 625 (UNS N06625) were installed, subsequently removed, and examined as a function of time. Of the various alloys tested, Alloys 625 and HR160 had the best performance in terms of the amount of thickness loss, and the extent of internal damage exhibited. However, those alloys were still susceptible to corrosion by the fireside (fluidized bed) environment and, therefore, will require replacement over time. Despite the observed corrosion, those two alloys significantly extended the nozzle life beyond that of Type 310H stainless steel. Nozzle design was found to have a strong influence on the apparent corrosion resistance of Alloy 625 and, therefor...
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Corrosion of Alloys in a Simulated Wood-Waste Fluidizing Bed Power Boiler Environment
CORROSION, 2006Co-Authors: J. R. Kish, D. L. Singbeil, P. EngAbstract:Abstract Rapid corrosion of Type 310H (UNS S31009) stainless steel fluidizing bed nozzles was observed shortly after start-up of a fluidizing bed Power Boiler designed to combust a mixture of salt-...
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Fouling and corrosion of bed nozzles in a bubbling fluidized-bed Power Boiler
Journal of Failure Analysis and Prevention, 2006Co-Authors: R. Prescott, J. R. Kish, D. L. SingbeilAbstract:An inspection of the floor in a bubbling fluidized-bed Power Boiler during a planned shutdown revealed significant corrosion of the type 310H stainless steel (UNS S31009) bed nozzles. One severely corroded bed nozzle was removed, along with samples of the deposit encasing the surface of the bed nozzle, for a subsequent failure analysis. The deposit covering the external (fireside) surface of the bed nozzle was almost entirely sodium and potassium chlorides, which covered a thick layer of corrosion product on the bed nozzle surface. The corrosion product was predominantly oxides of chromium, nickel, and iron. Chlorides were also found interspersed through the layer of corrosion product. It is concluded that the fireside corrosion was predominantly caused by chlorine-containing compounds (active oxidation). Overheating induced by the fouling, particularly within the air holes, is believed to be a major factor influencing corrosion.