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02488 Modelling wood combustion under fixed bed conditions
09 Combustion (burners, combustion systems) 03/02481 continuous
High pressure hydropyrolysis free-fall reactor
of coals by using a
XL W. -C. et al. Fuel. 2003. 82. (6). 677-685 Rapid hydropyrolysis of coal wasp carried out at temperatures ranging from 923 to 1123 K and Hz pressures up to 7 MPa by using a continuous free-fall pyrolyser. The effects of the reaction conditionson oroduct vields were investigated. Carbon mass balance was fairlv eood. It was revealed that a largi amount of methane was produced’d& to the hydrogenolysis of higher hydrocarbons and the hydrogasification of char. The influence of pvrolvsis temperature was simrificant on both reactions while Hz press&e mainly affected the latte;. A considerable amount of reactive carbon was formed during hydropyrolysis of coal. It was converted to methane at high temperatures and high Hz pressures, while the hydrogasification of reactive carbon takes place relatively slowly at low temperatures and low Hz pressures, resulting in a low overall carbon conversion. The coal conversions observed in the present study were much higher than those obtained with using reactors where the contact between coal particles and Hz is insufficient.
03/02482 Indirect and direct reaction effect in wustite-coal char composite elevated temperatures
rates and acceleration pellets heated at
Meng, F. ef al. Tetsu IO Hugune, 2003. 89, (2), 2299236. (In Japanese) The weight loss curves of wustiteicoal char composite pellets were measured, and the rate is was much greater than the overall rate of the indirect reactions of reduction and gasification. The indirect reaction rates were calculated by substituting the rate constant of reduction and the constant of iron catalysing gasification estimated by the reduction of the wustite and gasification of the char in electrolytic iron-char composite pellets into the rate equation of the grain model. The large difference in the experimental and calculated weight loss curves may be attributed to the direct reactions of wustite with char and carbon dissolved in the reduced iron. The weight loss curves of the direct reaction were gravimetrically measured in vacuum. The experimental weight loss curves were still significantly higher than the sum of the weight loss curves of the calculated indirect reactions and direct reactions in the later stage of the reactions of the composite pellets. The significant acceleration effect of the close mixing of wustite and char in the pellets can be attributed to the direct reduction of wustite with dissolved carbon in indirectly reduced iron.
03/02483 Method and apparatus rotary kiln with improved burner
for fuel combustion
in
Fujii, T. et al. Jpn. Kokai Tokkyo Koho JP 2003 83,519 (Cl. F23G5; 20), 19 Mar 2003, Appl. 2001/274,160. (In Japanese) The method is carried out by blowing the main fuel (e.g. powdered coal) and primary air into the rotary kiln via a burner comprising an outer primary-air outlet; a powdered-coal outlet having a plurality of discharge passages as a group; and an inner primary-air outlet, annularly arranged, in series, from outside toward the center, and blowing combustible waste (e.g. waste plastic, wood) as auxiliary fuel via portion of the discharge passages, to improve combustion.
03/02484 discharge
Method for prevention in coke oven
of black smoke
from
Sueivama. M. Jun. Kokai Tokkvo Koho JP 2003 82.357 (Cl. ClOB451 00; i9 Mar 2Od3, Appl. 2001/2?6,356. (In Japanese) ’ The method is carried out by collecting combustion flue gas from each coke oven into a single -dust-removal machine to remove dust containing unburned components, then forced blowing the treated flue gas to the stacks by a blower via recycle loop for discharge without black smoke.
03/02485 Modelin for pyrolysis and heat transfer tiff ects
of solid particle:
kinetics
Babu, B. V. and Chaurasia, A. S. Energy Conversion and Management, 2003. 44. (14). 2251-2275. In the present study, a mathematical model to describe the pyrolysis of a single solid particle of biomass is developed by incorporating improvements in the existing model reported in literature. It couples the heat transfer equation with the chemical kinetics equations. The pyrolysis rate has been simulated by a kinetic scheme involving three reactions (primary and secondary): two parallel reactions and a third for the secondarv interactions between the volatile and gaseous products and the char. The dependence of convective heat Gansfer coefficient on Reynolds number and Prandtl number is incorporated in the model. A finite difference method using a pure implicit scheme is used for solving the heat transfer equation and the Runge-Kutta 4th order method for the chemical kinetics equations. The model equation is solved for cylindrical pellets, spheres and slab geometries of equivalent radius ranging from 0.00025 to 0.013 m and temperature ranging from 303 to 1000 K. The simulated results obtained using the present model are in excellent agreement with the experimental data, much better than the agreement with the earlier models reported in the literature. 400
Fuel
and
Energy
Abstracts
November
2003
03lO2488 conditions
Modelling
wood combustion
under fixed bed
Bruch, C. et N/. I,‘uP/, 2003. X2. (6). 72% 73X. A computer model describing the conversion of wood under packed bed conditions is presented. The packed bed is considered to be an arrangement of a finite number of particles, typically sized between S and 25 mm, with a void space left between them. Each particle is undergoing a thermal conversion process, which is described by a onedimensional and transient model. Within the single-particle model, heating, drying, pyrolysis, gasification and combustion are considered, whereby each particle exchanges energy due to conduction and radiation with its neighbours. Because of the one-dimensional discretization of the particles, heat transfer and mass transfer is taken into account explicitly. Therefore, no macrokinetic data arc needed within the model. For ease of implementation and access, kinetic data and property data are stored in a database. The global conversion of the packed bed is represented by the contributions of single particles, where each particle is coupled to the surrounding gas phase by heat and mass transfer. For gas phase flow through the porous bed, the conservation equations for mass, momentum and energy arc solved on a Cartesian mesh by a Finite Volume method. Experiments have been performed to validate the single particle model for the conversion of beech wood during pyrolysis and char combustion. Agreement between experimental and predictions obtained by the model is very satisfactory. However, for wet wood, changes in structure seem to enhance the heat transfer to the solid that is not yet covered in the model.
03/02487 New approach for dynamic optimal power flow using Benders decomposition in a deregulated power market
Yamin, H. Y. et cl/. Ekctric Pon~r Sv.~tent.s Re.wrrch, 2003, 65. (2). 101 107. This paper proposed a novel Benders decomposition model of DOPF and applies a linear programming (simplex) method to solve it. Transmission constraints may represent intra-utility flows in a GENCO. The inclusion of transmission security (i.e. network) constraints assured a subsequent feasible solution for the DOPF oroblem. The oroblem was broken down into a base-case DOPF (without network constraints) and subproblems for checking the feasibility of the network constraints. For a given base-case DOPF scheduleapplied to the subproblems, line- flow violations were minimized by adjusting phase shifters and generating units. In case the current mix of scheduled units could not remove transmission violations, additional constraints were introduced in the master problem for rescheduling DOPF. A case study shows that the proposed model and algorithm is simple, fast and optimal.
03102488 Optimal design of HYPER target system based on the thermal and structural analysis of P&l31 spallation target and beam window Song, T. Y. and Tdk, N. 1. Annuls sf’ hiuclenr Ewergx. 2003, 30. (I?). 1297--l 308. KAERI (Korea Atomic Energy Research Institute) has been developing an accelerator driven transmutation system called HYPER (Hybrid Power Extraction Reactor). It is designed to transmute long-lived TRU and fission oroducts such as Tc-99 and I-129. Pb-Bi is use: as the coolant and target material at the same time. HYPER is expected to need about 20 mA proton beam to sustain a 1000 MWtt, power level. One of the problems to be solved is to design a target system that can accept such a high current while keeping the integrity of the target system. The cylindrical beam tube and spherical window is adopted as the basic window design of HYPER. The window diameter is varied to find the maximum allowable current based on the design criteria: Pb-Bi temperature <5OO”C, window temperature <6OO”C, Pb-Bi velocity <2m/s and window stress <160 MPa. The LAHET code is used to simulate heat eeneration. CFX and ANSYS are used for the thermal-hydraulics and sotress calculations, respectively. Based on the design criteria and the current HYPER system parameters, the maximum allowable current is calculated to be about8 mA, which is smaller than the required current. Therefore, an upgrade of the target design is under progress.
03lO2489 Physical and mechanical roperties of Cstrtsntbased products containing lnclne ratr on bottom ash
Filipponi, P. et al. WasteManagement, 2003, 23. (2), 145-156. This paper presents the results of a wider experimental programme conducted in the framework of the NNAPICS (‘Neural Network Analysis for Prediction of Interactions in Cemen&Waste Systems’) project funded by the European Commission and a number of industrial partners under Brite-EuRamIII. Based on the fact that bottom ashes from waste incineration are classified as non-hazardous wastes according to the European Waste Catalogue, the aim of the present work was to investigate the feasibility of addressing the potential use of such residues in cement-based mixtures. This issue was suggested by the analysis of the properties of different bottom ashes
High pressure hydropyrolysis free-fall reactor
of coals by using a
XL W. -C. et al. Fuel. 2003. 82. (6). 677-685 Rapid hydropyrolysis of coal wasp carried out at temperatures ranging from 923 to 1123 K and Hz pressures up to 7 MPa by using a continuous free-fall pyrolyser. The effects of the reaction conditionson oroduct vields were investigated. Carbon mass balance was fairlv eood. It was revealed that a largi amount of methane was produced’d& to the hydrogenolysis of higher hydrocarbons and the hydrogasification of char. The influence of pvrolvsis temperature was simrificant on both reactions while Hz press&e mainly affected the latte;. A considerable amount of reactive carbon was formed during hydropyrolysis of coal. It was converted to methane at high temperatures and high Hz pressures, while the hydrogasification of reactive carbon takes place relatively slowly at low temperatures and low Hz pressures, resulting in a low overall carbon conversion. The coal conversions observed in the present study were much higher than those obtained with using reactors where the contact between coal particles and Hz is insufficient.
03/02482 Indirect and direct reaction effect in wustite-coal char composite elevated temperatures
rates and acceleration pellets heated at
Meng, F. ef al. Tetsu IO Hugune, 2003. 89, (2), 2299236. (In Japanese) The weight loss curves of wustiteicoal char composite pellets were measured, and the rate is was much greater than the overall rate of the indirect reactions of reduction and gasification. The indirect reaction rates were calculated by substituting the rate constant of reduction and the constant of iron catalysing gasification estimated by the reduction of the wustite and gasification of the char in electrolytic iron-char composite pellets into the rate equation of the grain model. The large difference in the experimental and calculated weight loss curves may be attributed to the direct reactions of wustite with char and carbon dissolved in the reduced iron. The weight loss curves of the direct reaction were gravimetrically measured in vacuum. The experimental weight loss curves were still significantly higher than the sum of the weight loss curves of the calculated indirect reactions and direct reactions in the later stage of the reactions of the composite pellets. The significant acceleration effect of the close mixing of wustite and char in the pellets can be attributed to the direct reduction of wustite with dissolved carbon in indirectly reduced iron.
03/02483 Method and apparatus rotary kiln with improved burner
for fuel combustion
in
Fujii, T. et al. Jpn. Kokai Tokkyo Koho JP 2003 83,519 (Cl. F23G5; 20), 19 Mar 2003, Appl. 2001/274,160. (In Japanese) The method is carried out by blowing the main fuel (e.g. powdered coal) and primary air into the rotary kiln via a burner comprising an outer primary-air outlet; a powdered-coal outlet having a plurality of discharge passages as a group; and an inner primary-air outlet, annularly arranged, in series, from outside toward the center, and blowing combustible waste (e.g. waste plastic, wood) as auxiliary fuel via portion of the discharge passages, to improve combustion.
03/02484 discharge
Method for prevention in coke oven
of black smoke
from
Sueivama. M. Jun. Kokai Tokkvo Koho JP 2003 82.357 (Cl. ClOB451 00; i9 Mar 2Od3, Appl. 2001/2?6,356. (In Japanese) ’ The method is carried out by collecting combustion flue gas from each coke oven into a single -dust-removal machine to remove dust containing unburned components, then forced blowing the treated flue gas to the stacks by a blower via recycle loop for discharge without black smoke.
03/02485 Modelin for pyrolysis and heat transfer tiff ects
of solid particle:
kinetics
Babu, B. V. and Chaurasia, A. S. Energy Conversion and Management, 2003. 44. (14). 2251-2275. In the present study, a mathematical model to describe the pyrolysis of a single solid particle of biomass is developed by incorporating improvements in the existing model reported in literature. It couples the heat transfer equation with the chemical kinetics equations. The pyrolysis rate has been simulated by a kinetic scheme involving three reactions (primary and secondary): two parallel reactions and a third for the secondarv interactions between the volatile and gaseous products and the char. The dependence of convective heat Gansfer coefficient on Reynolds number and Prandtl number is incorporated in the model. A finite difference method using a pure implicit scheme is used for solving the heat transfer equation and the Runge-Kutta 4th order method for the chemical kinetics equations. The model equation is solved for cylindrical pellets, spheres and slab geometries of equivalent radius ranging from 0.00025 to 0.013 m and temperature ranging from 303 to 1000 K. The simulated results obtained using the present model are in excellent agreement with the experimental data, much better than the agreement with the earlier models reported in the literature. 400
Fuel
and
Energy
Abstracts
November
2003
03lO2488 conditions
Modelling
wood combustion
under fixed bed
Bruch, C. et N/. I,‘uP/, 2003. X2. (6). 72% 73X. A computer model describing the conversion of wood under packed bed conditions is presented. The packed bed is considered to be an arrangement of a finite number of particles, typically sized between S and 25 mm, with a void space left between them. Each particle is undergoing a thermal conversion process, which is described by a onedimensional and transient model. Within the single-particle model, heating, drying, pyrolysis, gasification and combustion are considered, whereby each particle exchanges energy due to conduction and radiation with its neighbours. Because of the one-dimensional discretization of the particles, heat transfer and mass transfer is taken into account explicitly. Therefore, no macrokinetic data arc needed within the model. For ease of implementation and access, kinetic data and property data are stored in a database. The global conversion of the packed bed is represented by the contributions of single particles, where each particle is coupled to the surrounding gas phase by heat and mass transfer. For gas phase flow through the porous bed, the conservation equations for mass, momentum and energy arc solved on a Cartesian mesh by a Finite Volume method. Experiments have been performed to validate the single particle model for the conversion of beech wood during pyrolysis and char combustion. Agreement between experimental and predictions obtained by the model is very satisfactory. However, for wet wood, changes in structure seem to enhance the heat transfer to the solid that is not yet covered in the model.
03/02487 New approach for dynamic optimal power flow using Benders decomposition in a deregulated power market
Yamin, H. Y. et cl/. Ekctric Pon~r Sv.~tent.s Re.wrrch, 2003, 65. (2). 101 107. This paper proposed a novel Benders decomposition model of DOPF and applies a linear programming (simplex) method to solve it. Transmission constraints may represent intra-utility flows in a GENCO. The inclusion of transmission security (i.e. network) constraints assured a subsequent feasible solution for the DOPF oroblem. The oroblem was broken down into a base-case DOPF (without network constraints) and subproblems for checking the feasibility of the network constraints. For a given base-case DOPF scheduleapplied to the subproblems, line- flow violations were minimized by adjusting phase shifters and generating units. In case the current mix of scheduled units could not remove transmission violations, additional constraints were introduced in the master problem for rescheduling DOPF. A case study shows that the proposed model and algorithm is simple, fast and optimal.
03102488 Optimal design of HYPER target system based on the thermal and structural analysis of P&l31 spallation target and beam window Song, T. Y. and Tdk, N. 1. Annuls sf’ hiuclenr Ewergx. 2003, 30. (I?). 1297--l 308. KAERI (Korea Atomic Energy Research Institute) has been developing an accelerator driven transmutation system called HYPER (Hybrid Power Extraction Reactor). It is designed to transmute long-lived TRU and fission oroducts such as Tc-99 and I-129. Pb-Bi is use: as the coolant and target material at the same time. HYPER is expected to need about 20 mA proton beam to sustain a 1000 MWtt, power level. One of the problems to be solved is to design a target system that can accept such a high current while keeping the integrity of the target system. The cylindrical beam tube and spherical window is adopted as the basic window design of HYPER. The window diameter is varied to find the maximum allowable current based on the design criteria: Pb-Bi temperature <5OO”C, window temperature <6OO”C, Pb-Bi velocity <2m/s and window stress <160 MPa. The LAHET code is used to simulate heat eeneration. CFX and ANSYS are used for the thermal-hydraulics and sotress calculations, respectively. Based on the design criteria and the current HYPER system parameters, the maximum allowable current is calculated to be about8 mA, which is smaller than the required current. Therefore, an upgrade of the target design is under progress.
03lO2489 Physical and mechanical roperties of Cstrtsntbased products containing lnclne ratr on bottom ash
Filipponi, P. et al. WasteManagement, 2003, 23. (2), 145-156. This paper presents the results of a wider experimental programme conducted in the framework of the NNAPICS (‘Neural Network Analysis for Prediction of Interactions in Cemen&Waste Systems’) project funded by the European Commission and a number of industrial partners under Brite-EuRamIII. Based on the fact that bottom ashes from waste incineration are classified as non-hazardous wastes according to the European Waste Catalogue, the aim of the present work was to investigate the feasibility of addressing the potential use of such residues in cement-based mixtures. This issue was suggested by the analysis of the properties of different bottom ashes