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02184 Soot formation during coal pyrolysis
10
A review of ash in conventional 97102178 based power systems
and advanced
coal-
Holcombo. N. T. Pmt. A,lntr. Ir~r. Pitl,shur$~ Coal Co~$ 1995. 12, l-6. This review briefly describes process conditions for conventional and advanced power systems. The advanced systems include both combustion and gasification processes. Problems in coal-based power generation system<, including deposition, agglomeration and sintering of bed materials, and aah attack are discussed. In addition. methods of mitigating ash from problems and change\ anticipated in ash use by converting conventional to advanced systems are explored. 97102179
calcination combustion
The role of thermally induced fractures in the and sulfation behavior of sorbents in fluidized bed
Liu. Y. c’t ul. PI-oc. A~rrl[r. /,I[. P~rr.shrr,~/tCocrl Con/‘.. 1995. 12, 210-224. The experiment discovered that, in the fluidized-hed combustion of coal, the calcination and aulfation behavior of dolostones and limestones were particle \ize dependent. 1.e. small+ize \orhents had better performance.
Sewage sludge combustion in 97102180 bed. Comparison of stationary and circulating techniques.
the fluidized fluidized bed
Werther. J. CI (I/. &I(,. In,. (‘o,~f: Fluid. Bed Cornh~~/.. 194.5. 13. (2). YSI462. Presents the rehultr of an investigation into CO and NO, emissions during the incineration of different digested sewage sludge samples in stationary and circulating fluidized hcd comhustors. The digested sewage sludges originated from different municipal wastewater treatment plants. They were fed into the combustors as either pre-dried granulates with h-13 wt.% water contents or as a slurry with water contents 70-80 wt.%. For comparison. bituminous and brown coals were also investigated. Results concerning the emissions of thc\r pollutants are discussed. 97102181
perature:
Single char particle effects of ash
combustion
at moderate
tem-
Chen. C. and Kojima. ‘T Fue/ P~ocrss. I’echnol., 1996, 47. (3), 215232. An investigation into the effects of ash content, ash layer heat and mass transfer on a single granulated char particle (IO-IX mm in diameter) combustion in an air stream (12 cm s -’ in cold base). The transient temperature of various ash content char particle burning in the surrounding g,as temperatures of 400 to I200 K was simulated. Agreement between simulated and experimental results was obtained hy adjusting the ash layer diffusion coefficient and heat conductance. surface emissivity and the reactlon rate constant.
97102182
Slag discharge
device
Engines (power generation and propuhon.
electrical vehcles)
containing SOZ at typical combustion temperature\. This resulted in considerable additional capture of sulfur by the reactivated sorhent. The optimum reactivation temperature for the tested ash appears to he ahout 4SO- for the tested ash. The observations iare explained in term\ of thermodynamic equilibrium and hulk diffusion mcchanlsm.
97102187 Study on combustion characteristics of four Chinese coal macerals by thermogravimetry Lu. J. er al. Rardiao Huuxue X~!hao, 1906. 24, (41. 3?Y-33-1. (In Chinese) Thermogravimetry was applied to determine the combustion characteristics of macerals from four coals and the effect of inherent mineral matter on combustion. According to characteristic temperature in the weight loss curve of TGA, the combustion hehaviour of the vitrinite concentrate was found to he hetter than that of inertinite concentrate.
A study 97102188 gasifier using DTF
on the slagging
behavior
of coal ash in
Kim, H. T. rt N/. Proc. Anntr. In/. Pi/t.\hlrrx/? Coul Cop~f:, IYYS, I?. 13-1X. In this study, slagging hehaviour of various coals during gasification was investigated using a drop tuhe furnace. It was found that mineral matter of the Alaskan coal was transformed to mullite and gehlenitc during to gasification. In addition. the minerals were ultimately transformed amorphous aluminosilicate phase. Flux effect was also determined.
97102189 pressurized
Test results from the department of energy’s fluidized bed combustion hot gas cleanup program Dennis, R. A. Proc. Annlr. Int. Pitt.s/xqh Cool c‘onf.. 199.5, 12. 3X5-390.
A summary of operations and conclusions from the last two test campaigns of the Department of Energy’s Pressurized Fluidized Bed Combustion Hot Gas Cleanup Program is presented. This was implemented hy the American Electricity Power Service Corporation. In these tests. the Westinghouse Advanced Particle Filter (APF) operated on a one-seventh flow from the Tidd 70.MWe pressurized fluidized hed comhustor. During these tests, the filter operated as predicted, with extremely high particulate removal.
Transition of thermal 97102190 tion in circulating fluidized bed
power plants to coal combus-
Ryabov. G. A. et al. E/&r. Sm.. 1906, (X). 18-21. (In Russian) The authors discuss the technologies for boiler firing in a fluidized bed and the use of these technologies to modernize existing boilers in power stations.
in coal combustors
Kate. S. and Fukuda. H. Jpn. Kokai Tokkyo Koho JP 0X.188,782 [96,lXX.782] (Cl. CIOJ3i46). 2.1 Jul 1996, Appl. 9513.971. I3 Jan 1995; 4 pp. (In Japanese) This paper reports the use of a rotating plate in spouted-bed coal gasification. The plate rapidly discharges the slag from the bottom part of a coal comhustor, comprising means for trapping and feeding the molten slag into the top end of funnel-shaped outlet, and means for preventing turbulent flow of molten slag inside the comhustor.
Some investigations on heat transfer in a hot circulating fluidized bed Nag, P. K. and Reddy. B. V. Proc. Itlr. Conf. Fluid. Bed Comhlrpr., 1905. 13.
10
ENGINES
971021 a3
(2). 1327-1335. Presents the results of an investigation into the heat-transfer characteristics at different hed heights along the riser column in a circulating fluidized bed (CFB) unit. The new data is compared with published literature.
Soot formation during coal pyrolysis 97102184 Ma. J. IYYh, I72 pp. Avail. degree-granting institution. From Dis.\. Ahstr. 1n1.. R IYYh, S7. (4). 271s. 97102185 furnaces
Special
measurements
in combustion
equipment
Ochodek, T. (of ul. from Annrr. fm. I’ilrshn!@ Coctl Conf.. IYYS, 12, 42342X. A summary of the authors‘ knowledge from the measurement of temperature and concentration fields taken from combustion equipment furnaces is reported. The obtained results serve in the research into the course of the combustion process and in that of the formation of pollutants. for example NO,. The special measurement technique makes it possible to find out the concentration and temperature field course for a temperature as high as IS00 C. On the basis of the ohtained results a proposal was formulated for the reconstruction of existing boilers or the construction of new boilers with an aim to ensure the maximum combustion efficiency with a minimal formation of pollutants.
97102186
Spent sorbent
reactivation
using steam
Julien, S. et lrl. Proc. Irrr. C‘oofFhrid. Bed Comhust., 1995, 13, (2), X41-X49. Spent sorhent and fly ash captured in the haghouse of a circulating fluidized bed comhustor were used in experiments carried out in a bench scale Huidized hed reactor. The spent sorbent was reactivated with steam at temperatures of 250-600 and then exposed to a simulated flue gas mixture
Power Generation and Propulsion, Electrical Vehicles
97102191 Analogy between electrical machines and heat transfer-irreversible heat engines Bejan. A. and Dan, N. Inr. J. Hccrr Moss Tmnrfer, IY9h. 30, (17). 3hS93666. The paper presents the extension of the thermodynamic and heat transfer optimization approach, originally developed for heat engines, to electrical machines. Four models of thermodynamically lrreversihle electric motors with heat transfer to the ambient are proposed and optimized: general reversible motor in series with its resistance, induction motor with transformer, synchronous motor with transformer and d.c. motor. The convection efficiency at maximum power is l/2. When, as in specific applications, the operating temperature of the windings must not exceed a specified level, the power output is lower and the efficiency higher. In the case of an electrical power generator it is shown that the generator and the heat engine that drives it can he optimized separately for maximum power.
Anal sis of gas-turbine cycles with thermo-chemi97102192 cal conversion o Y the working medium. 2. External recovery of removed heat (combined cycles) Kolesnik, V. V. and Orlik, V. M. Ekotekllnoi. Kcs~r~.sovAe~~zh~~~~i~. 1096. (?), 15-19. (In Ukrainian) An investigation into the possibility of fuel utilization efficiency increasing due to thermo-chemical actuating medium conversion in open-. closed- and combined-cycle gas turbines. The efficiency of the system with external recovery of heat removed from actuating body ~a\ analyzed.
Fuel and Energy Abstracts
May 1997
175
A review of ash in conventional 97102178 based power systems
and advanced
coal-
Holcombo. N. T. Pmt. A,lntr. Ir~r. Pitl,shur$~ Coal Co~$ 1995. 12, l-6. This review briefly describes process conditions for conventional and advanced power systems. The advanced systems include both combustion and gasification processes. Problems in coal-based power generation system<, including deposition, agglomeration and sintering of bed materials, and aah attack are discussed. In addition. methods of mitigating ash from problems and change\ anticipated in ash use by converting conventional to advanced systems are explored. 97102179
calcination combustion
The role of thermally induced fractures in the and sulfation behavior of sorbents in fluidized bed
Liu. Y. c’t ul. PI-oc. A~rrl[r. /,I[. P~rr.shrr,~/tCocrl Con/‘.. 1995. 12, 210-224. The experiment discovered that, in the fluidized-hed combustion of coal, the calcination and aulfation behavior of dolostones and limestones were particle \ize dependent. 1.e. small+ize \orhents had better performance.
Sewage sludge combustion in 97102180 bed. Comparison of stationary and circulating techniques.
the fluidized fluidized bed
Werther. J. CI (I/. &I(,. In,. (‘o,~f: Fluid. Bed Cornh~~/.. 194.5. 13. (2). YSI462. Presents the rehultr of an investigation into CO and NO, emissions during the incineration of different digested sewage sludge samples in stationary and circulating fluidized hcd comhustors. The digested sewage sludges originated from different municipal wastewater treatment plants. They were fed into the combustors as either pre-dried granulates with h-13 wt.% water contents or as a slurry with water contents 70-80 wt.%. For comparison. bituminous and brown coals were also investigated. Results concerning the emissions of thc\r pollutants are discussed. 97102181
perature:
Single char particle effects of ash
combustion
at moderate
tem-
Chen. C. and Kojima. ‘T Fue/ P~ocrss. I’echnol., 1996, 47. (3), 215232. An investigation into the effects of ash content, ash layer heat and mass transfer on a single granulated char particle (IO-IX mm in diameter) combustion in an air stream (12 cm s -’ in cold base). The transient temperature of various ash content char particle burning in the surrounding g,as temperatures of 400 to I200 K was simulated. Agreement between simulated and experimental results was obtained hy adjusting the ash layer diffusion coefficient and heat conductance. surface emissivity and the reactlon rate constant.
97102182
Slag discharge
device
Engines (power generation and propuhon.
electrical vehcles)
containing SOZ at typical combustion temperature\. This resulted in considerable additional capture of sulfur by the reactivated sorhent. The optimum reactivation temperature for the tested ash appears to he ahout 4SO- for the tested ash. The observations iare explained in term\ of thermodynamic equilibrium and hulk diffusion mcchanlsm.
97102187 Study on combustion characteristics of four Chinese coal macerals by thermogravimetry Lu. J. er al. Rardiao Huuxue X~!hao, 1906. 24, (41. 3?Y-33-1. (In Chinese) Thermogravimetry was applied to determine the combustion characteristics of macerals from four coals and the effect of inherent mineral matter on combustion. According to characteristic temperature in the weight loss curve of TGA, the combustion hehaviour of the vitrinite concentrate was found to he hetter than that of inertinite concentrate.
A study 97102188 gasifier using DTF
on the slagging
behavior
of coal ash in
Kim, H. T. rt N/. Proc. Anntr. In/. Pi/t.\hlrrx/? Coul Cop~f:, IYYS, I?. 13-1X. In this study, slagging hehaviour of various coals during gasification was investigated using a drop tuhe furnace. It was found that mineral matter of the Alaskan coal was transformed to mullite and gehlenitc during to gasification. In addition. the minerals were ultimately transformed amorphous aluminosilicate phase. Flux effect was also determined.
97102189 pressurized
Test results from the department of energy’s fluidized bed combustion hot gas cleanup program Dennis, R. A. Proc. Annlr. Int. Pitt.s/xqh Cool c‘onf.. 199.5, 12. 3X5-390.
A summary of operations and conclusions from the last two test campaigns of the Department of Energy’s Pressurized Fluidized Bed Combustion Hot Gas Cleanup Program is presented. This was implemented hy the American Electricity Power Service Corporation. In these tests. the Westinghouse Advanced Particle Filter (APF) operated on a one-seventh flow from the Tidd 70.MWe pressurized fluidized hed comhustor. During these tests, the filter operated as predicted, with extremely high particulate removal.
Transition of thermal 97102190 tion in circulating fluidized bed
power plants to coal combus-
Ryabov. G. A. et al. E/&r. Sm.. 1906, (X). 18-21. (In Russian) The authors discuss the technologies for boiler firing in a fluidized bed and the use of these technologies to modernize existing boilers in power stations.
in coal combustors
Kate. S. and Fukuda. H. Jpn. Kokai Tokkyo Koho JP 0X.188,782 [96,lXX.782] (Cl. CIOJ3i46). 2.1 Jul 1996, Appl. 9513.971. I3 Jan 1995; 4 pp. (In Japanese) This paper reports the use of a rotating plate in spouted-bed coal gasification. The plate rapidly discharges the slag from the bottom part of a coal comhustor, comprising means for trapping and feeding the molten slag into the top end of funnel-shaped outlet, and means for preventing turbulent flow of molten slag inside the comhustor.
Some investigations on heat transfer in a hot circulating fluidized bed Nag, P. K. and Reddy. B. V. Proc. Itlr. Conf. Fluid. Bed Comhlrpr., 1905. 13.
10
ENGINES
971021 a3
(2). 1327-1335. Presents the results of an investigation into the heat-transfer characteristics at different hed heights along the riser column in a circulating fluidized bed (CFB) unit. The new data is compared with published literature.
Soot formation during coal pyrolysis 97102184 Ma. J. IYYh, I72 pp. Avail. degree-granting institution. From Dis.\. Ahstr. 1n1.. R IYYh, S7. (4). 271s. 97102185 furnaces
Special
measurements
in combustion
equipment
Ochodek, T. (of ul. from Annrr. fm. I’ilrshn!@ Coctl Conf.. IYYS, 12, 42342X. A summary of the authors‘ knowledge from the measurement of temperature and concentration fields taken from combustion equipment furnaces is reported. The obtained results serve in the research into the course of the combustion process and in that of the formation of pollutants. for example NO,. The special measurement technique makes it possible to find out the concentration and temperature field course for a temperature as high as IS00 C. On the basis of the ohtained results a proposal was formulated for the reconstruction of existing boilers or the construction of new boilers with an aim to ensure the maximum combustion efficiency with a minimal formation of pollutants.
97102186
Spent sorbent
reactivation
using steam
Julien, S. et lrl. Proc. Irrr. C‘oofFhrid. Bed Comhust., 1995, 13, (2), X41-X49. Spent sorhent and fly ash captured in the haghouse of a circulating fluidized bed comhustor were used in experiments carried out in a bench scale Huidized hed reactor. The spent sorbent was reactivated with steam at temperatures of 250-600 and then exposed to a simulated flue gas mixture
Power Generation and Propulsion, Electrical Vehicles
97102191 Analogy between electrical machines and heat transfer-irreversible heat engines Bejan. A. and Dan, N. Inr. J. Hccrr Moss Tmnrfer, IY9h. 30, (17). 3hS93666. The paper presents the extension of the thermodynamic and heat transfer optimization approach, originally developed for heat engines, to electrical machines. Four models of thermodynamically lrreversihle electric motors with heat transfer to the ambient are proposed and optimized: general reversible motor in series with its resistance, induction motor with transformer, synchronous motor with transformer and d.c. motor. The convection efficiency at maximum power is l/2. When, as in specific applications, the operating temperature of the windings must not exceed a specified level, the power output is lower and the efficiency higher. In the case of an electrical power generator it is shown that the generator and the heat engine that drives it can he optimized separately for maximum power.
Anal sis of gas-turbine cycles with thermo-chemi97102192 cal conversion o Y the working medium. 2. External recovery of removed heat (combined cycles) Kolesnik, V. V. and Orlik, V. M. Ekotekllnoi. Kcs~r~.sovAe~~zh~~~~i~. 1096. (?), 15-19. (In Ukrainian) An investigation into the possibility of fuel utilization efficiency increasing due to thermo-chemical actuating medium conversion in open-. closed- and combined-cycle gas turbines. The efficiency of the system with external recovery of heat removed from actuating body ~a\ analyzed.
Fuel and Energy Abstracts
May 1997
175