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02242 Corrosion in ultra supercritical boilers for straw combustion
08 Steam raising (boiler operation/design) presented in order to evaluate the control flexibility. The results of three control problems are finally shown in order to prove the reliability of the suggested control technique.
of usable energy is generally more expensive. These high costs probably represent the main reason for the limited use of renewable energies in Germany.
Performance analysis of a small wind powered reverse osmosis plant
98102235 Kalinowski, 1997, Appl. Describes painting in
9wo2230
Infield, D. Solar Energy, 1997, 61, (6), 415-421. The performance of a small wind powered reverse osmosis plant has been assessed with a stand-alone systems analysis approach. The study is concerned with the sensitivity of operation to key parameters: wind speed, battery storage capacity and reverse osmosis operating pressure. The results of such a system analysis are shown to occasionally be inconsistent with more simplistic approaches sometimes adopted in this applications area. A provisional calculation of annual expected water delivery has also been undertaken. Detailed modelling results are presented and discussed. The paper concludes that the ideal operational pressure is not always the maximum design pressure, but can depend on the site wind speed. Since water storage is far cheaper than electricity storage, there is motivation to minimize the capacity of the battery store. The most effective battery capacity would seem to be in the range of 4 to 8 h at nominal rated load for the reverse osmosis plant, with the actual value critically dependent on wind speed at the site.
98102236 Use of sewage sludge energy in Swarzewo Ostejski, A. Gaz, Woda Tech. Sanit., 1997, 71, (lo), 370-373. (In Polish) After dewatering to moisture content 60 wt%, wastewater treatment sludge is mixed with fine coal in the ratio 1:l and used as fuel to fire a hot-water boiler (output 100 kW) at a sewage treatment plant in Swarzewo, Poland.
08
99102231 Production costing and economic analysis of power systems containing wind energy conversion systems Tripathy, S. C. et al. Energy Convers. Mgmt, 1998, 39, (7) 649-659. It is possible to generate electricity by both conventional sources (nuclear, coal, diesel, etc.) and non-conventional sources (such as wind, tidal, solar energy, etc.). There currently exists a growing interest in the nonconventional sources of energy, as they are limitless and cheap to operate and wind is one of the best potential candidates for this role. The effect of combining wind energy conversion systems (WECS) with the conventional power system is studied here. Fast transform techniques are used to determine the production costing of the combined system. An economic analysis is performed, based on the production costs, to study the benefits obtained over the lifetime of the WECS. 98102232
Simultaneous frequency and voltage control of wind-diesel power systems using energy storage
Mufti, M.-U.-D. et al. Int. J. Energy Res., 1998, 22, (3), 221-235. A new scheme for smoothing out the voltage and frequency fluctuations simultaneously in a hybrid wind-diesel system using a superconducting magnetic energy storage (SMES) unit is presented. The SMES unit located at induction generators’ terminal bus, uses local measurements for exchanging real and reactive powers simultaneously in four quadrants. Complete model of the hybrid wind-diesel SMES system is developed and is used for eigenvalue analysis and design of controllers. Computer simulation results illustrate the positive impact of the SMES unit on the quality of the supply and furthermore some modifications of the controller design are proposed.
Soclo-economic lessons from Denmark
98102233
assessment
of wind power-
Munksgaard, J. and Larsen, A. Energy Policy, 1998, 26, (2) 85-93. Results from a study on the social assessment of wind power in Denmark are reported. Using the cost effectiveness paradigm production costs for wind power are compared to reference figures for central power production based on coal and natural gas. The external production costs which arise from the emissions of COz, SOz and NO, from combustion of fossil fuel and from noise and visual effects from wind mills are added to the internal costs. The macro-economic effects on employment and the balance of payments from investing in a 1000 MW wind power development which is about double the total capacity of the present Danish level are considered. Taking into account the Danish obligation of reducing COz emissions by 20% in 2005 compared to 1988, the main result of the investigations is that the environmental benefits of wind power are so significant that from a socio-economic point of view wind power and natural gas power are equal. Having a coal-fired power plant as the reference technology, wind power is more advantageous.
Others, including Development, Economics 98102234
Provlding low-temperature heat with renewable energies. An energy economical comparison
Lux, R. and Kaltschmitt, M. Erdoel, Erdgas, Kohle, 1998, 114, (l), 31-37. (In German) The possible use of renewable energies is discussed with great interest for the provision of heat and electricity in Germany. Although they offer advantages in environmental aspects, their actual use is very small. The aim of this paper is make a comparison between the costs of providing lowtemperature heat from renewable energies such as solar radiation, geothermal energy, and biomass with those from fossil fuels. The results of this comparison show that the use of renewable energies for the provision
202
Fuel and Energy Abstracts
May 1998
System for utilising volatile air pollutants as fuel C. and Romanski, T. Pal. PL 172,365 (Cl. ClOKl/OO), 30 Sep 301,165, 23 Nov 1993, 4 pp. (In Polish) a system for catching volatile pollutants generated during various paint shops and utilizing them as fuel.
STEAM RAISING Boiler Operation/Design
9wo2237 Apparatus for dust-charged wet-type desulfurization of coal-fired boiler flue gases Yokosuka, T. et al. Jpn. Kokai Tokkyo Koho JP 09 57,054 [97 57,054] (Cl. BOlD53/50), 4 Mar 1997, Appl. 951217,096, 25 Aug 1995; 7 pp. (In Japanese) This apparatus provides a means for removing coal dust and mist from gaseous effluents of a coal-fired boiler flue gas desulfurization system using a crimped plate mist eliminator. The mist eliminator may be equipped with grounded electrode plates, corona-discharge electrode wires for trapping mist, and means for washing the deposits of electrically charged dust from the crimped plate in a gas passage partition plate perpendicular to the gas flow. Smoke formation is prevented and dust removal increased with this apparatus. 9WO2238 Ash behavior In a CFB boiler during combustion of coal, peat or wood Skrifvars, B.-J. et nl. Fuel, 1998 (Pub. 1997) 77, (112). 65-70. Selected results are reported from an extensive on-site measurement campaign where the ash behaviour in a 12 MW CFB boiler was studied during firing of coal, peat and wood. Samples were taken from all in-going and out-going solid material streams, as well as from the bed and the return leg. Deposit samples were further collected from the cyclone inlet and from two different locations in the convective path. Furthermore, the boiler operation was monitored, including collection of operational data, flue gas temperature profiles and emissions. The differences in the ash chemistry that were detected between the three different combustion cases are discussed and the paper draws conclusions on the impact of the chemical and the bed agglomeration and fouling tendency for each fuel.
Case study of the conversion of tangential- and wall-fired units to low-NO, combustion: impact on fly ash quality
gal02239
Hower, J. C. et al. Waste Management, 1997, 17, (4), 219-229. Fly ash quality can be influenced by the conversion of boilers to low-NO, combustion. It is affected in terms of the amount and forms of carbon, the overall fly ash fineness and the relative amount of glass versus crystalline inorganic phases. All of these factors can influence the potential for marketing fly ash utilization. In this study, three coal-fired combustors were studied before and after conversion: two tangentially fired and one wallfired. The post-conversion fly ash was higher in carbon than the preconversion ash from the same unit in all cases. The fly ashes in at least two of the units would appear to have post-conversion ashes which still fall within the regional guidelines for the limit of carbon.
99lo2240 Cofiring wood waste and coal In cyclone boilers: test results and prospectus Tilman, D. et al. Proc. Biomass Conf. Am.: Energy, Environ., Agric. Ind., 2nd, 1995, 382-389. The potentials offered by the co-firing wood waste in coal-fired utility boilers include reducing fuel costs, supporting local economic development and addressing environmental concerns ranging from emissions of NO, emissions to greenhouse gas. Consequently, TVA and EPRI developed an extensive programme initially involving case studies and calculations and extending into the conduct of co-firing tests at Boiler #2 of the Allen Fossil Plant. The wood waste co-fired was sawdust obtained locally and the coal employed was an eastern bituminous coal. The influence of co-firing on fuel preparation and handling, fuel management operations, boiler efficiencies and operating temperatures and the formation and control of airborne emissions was investigated. The tests demonstrated the potential for significant technical, economic and environmental benefits associated with wood co-firing, including improving dust control during fuel handling,
of usable energy is generally more expensive. These high costs probably represent the main reason for the limited use of renewable energies in Germany.
Performance analysis of a small wind powered reverse osmosis plant
98102235 Kalinowski, 1997, Appl. Describes painting in
9wo2230
Infield, D. Solar Energy, 1997, 61, (6), 415-421. The performance of a small wind powered reverse osmosis plant has been assessed with a stand-alone systems analysis approach. The study is concerned with the sensitivity of operation to key parameters: wind speed, battery storage capacity and reverse osmosis operating pressure. The results of such a system analysis are shown to occasionally be inconsistent with more simplistic approaches sometimes adopted in this applications area. A provisional calculation of annual expected water delivery has also been undertaken. Detailed modelling results are presented and discussed. The paper concludes that the ideal operational pressure is not always the maximum design pressure, but can depend on the site wind speed. Since water storage is far cheaper than electricity storage, there is motivation to minimize the capacity of the battery store. The most effective battery capacity would seem to be in the range of 4 to 8 h at nominal rated load for the reverse osmosis plant, with the actual value critically dependent on wind speed at the site.
98102236 Use of sewage sludge energy in Swarzewo Ostejski, A. Gaz, Woda Tech. Sanit., 1997, 71, (lo), 370-373. (In Polish) After dewatering to moisture content 60 wt%, wastewater treatment sludge is mixed with fine coal in the ratio 1:l and used as fuel to fire a hot-water boiler (output 100 kW) at a sewage treatment plant in Swarzewo, Poland.
08
99102231 Production costing and economic analysis of power systems containing wind energy conversion systems Tripathy, S. C. et al. Energy Convers. Mgmt, 1998, 39, (7) 649-659. It is possible to generate electricity by both conventional sources (nuclear, coal, diesel, etc.) and non-conventional sources (such as wind, tidal, solar energy, etc.). There currently exists a growing interest in the nonconventional sources of energy, as they are limitless and cheap to operate and wind is one of the best potential candidates for this role. The effect of combining wind energy conversion systems (WECS) with the conventional power system is studied here. Fast transform techniques are used to determine the production costing of the combined system. An economic analysis is performed, based on the production costs, to study the benefits obtained over the lifetime of the WECS. 98102232
Simultaneous frequency and voltage control of wind-diesel power systems using energy storage
Mufti, M.-U.-D. et al. Int. J. Energy Res., 1998, 22, (3), 221-235. A new scheme for smoothing out the voltage and frequency fluctuations simultaneously in a hybrid wind-diesel system using a superconducting magnetic energy storage (SMES) unit is presented. The SMES unit located at induction generators’ terminal bus, uses local measurements for exchanging real and reactive powers simultaneously in four quadrants. Complete model of the hybrid wind-diesel SMES system is developed and is used for eigenvalue analysis and design of controllers. Computer simulation results illustrate the positive impact of the SMES unit on the quality of the supply and furthermore some modifications of the controller design are proposed.
Soclo-economic lessons from Denmark
98102233
assessment
of wind power-
Munksgaard, J. and Larsen, A. Energy Policy, 1998, 26, (2) 85-93. Results from a study on the social assessment of wind power in Denmark are reported. Using the cost effectiveness paradigm production costs for wind power are compared to reference figures for central power production based on coal and natural gas. The external production costs which arise from the emissions of COz, SOz and NO, from combustion of fossil fuel and from noise and visual effects from wind mills are added to the internal costs. The macro-economic effects on employment and the balance of payments from investing in a 1000 MW wind power development which is about double the total capacity of the present Danish level are considered. Taking into account the Danish obligation of reducing COz emissions by 20% in 2005 compared to 1988, the main result of the investigations is that the environmental benefits of wind power are so significant that from a socio-economic point of view wind power and natural gas power are equal. Having a coal-fired power plant as the reference technology, wind power is more advantageous.
Others, including Development, Economics 98102234
Provlding low-temperature heat with renewable energies. An energy economical comparison
Lux, R. and Kaltschmitt, M. Erdoel, Erdgas, Kohle, 1998, 114, (l), 31-37. (In German) The possible use of renewable energies is discussed with great interest for the provision of heat and electricity in Germany. Although they offer advantages in environmental aspects, their actual use is very small. The aim of this paper is make a comparison between the costs of providing lowtemperature heat from renewable energies such as solar radiation, geothermal energy, and biomass with those from fossil fuels. The results of this comparison show that the use of renewable energies for the provision
202
Fuel and Energy Abstracts
May 1998
System for utilising volatile air pollutants as fuel C. and Romanski, T. Pal. PL 172,365 (Cl. ClOKl/OO), 30 Sep 301,165, 23 Nov 1993, 4 pp. (In Polish) a system for catching volatile pollutants generated during various paint shops and utilizing them as fuel.
STEAM RAISING Boiler Operation/Design
9wo2237 Apparatus for dust-charged wet-type desulfurization of coal-fired boiler flue gases Yokosuka, T. et al. Jpn. Kokai Tokkyo Koho JP 09 57,054 [97 57,054] (Cl. BOlD53/50), 4 Mar 1997, Appl. 951217,096, 25 Aug 1995; 7 pp. (In Japanese) This apparatus provides a means for removing coal dust and mist from gaseous effluents of a coal-fired boiler flue gas desulfurization system using a crimped plate mist eliminator. The mist eliminator may be equipped with grounded electrode plates, corona-discharge electrode wires for trapping mist, and means for washing the deposits of electrically charged dust from the crimped plate in a gas passage partition plate perpendicular to the gas flow. Smoke formation is prevented and dust removal increased with this apparatus. 9WO2238 Ash behavior In a CFB boiler during combustion of coal, peat or wood Skrifvars, B.-J. et nl. Fuel, 1998 (Pub. 1997) 77, (112). 65-70. Selected results are reported from an extensive on-site measurement campaign where the ash behaviour in a 12 MW CFB boiler was studied during firing of coal, peat and wood. Samples were taken from all in-going and out-going solid material streams, as well as from the bed and the return leg. Deposit samples were further collected from the cyclone inlet and from two different locations in the convective path. Furthermore, the boiler operation was monitored, including collection of operational data, flue gas temperature profiles and emissions. The differences in the ash chemistry that were detected between the three different combustion cases are discussed and the paper draws conclusions on the impact of the chemical and the bed agglomeration and fouling tendency for each fuel.
Case study of the conversion of tangential- and wall-fired units to low-NO, combustion: impact on fly ash quality
gal02239
Hower, J. C. et al. Waste Management, 1997, 17, (4), 219-229. Fly ash quality can be influenced by the conversion of boilers to low-NO, combustion. It is affected in terms of the amount and forms of carbon, the overall fly ash fineness and the relative amount of glass versus crystalline inorganic phases. All of these factors can influence the potential for marketing fly ash utilization. In this study, three coal-fired combustors were studied before and after conversion: two tangentially fired and one wallfired. The post-conversion fly ash was higher in carbon than the preconversion ash from the same unit in all cases. The fly ashes in at least two of the units would appear to have post-conversion ashes which still fall within the regional guidelines for the limit of carbon.
99lo2240 Cofiring wood waste and coal In cyclone boilers: test results and prospectus Tilman, D. et al. Proc. Biomass Conf. Am.: Energy, Environ., Agric. Ind., 2nd, 1995, 382-389. The potentials offered by the co-firing wood waste in coal-fired utility boilers include reducing fuel costs, supporting local economic development and addressing environmental concerns ranging from emissions of NO, emissions to greenhouse gas. Consequently, TVA and EPRI developed an extensive programme initially involving case studies and calculations and extending into the conduct of co-firing tests at Boiler #2 of the Allen Fossil Plant. The wood waste co-fired was sawdust obtained locally and the coal employed was an eastern bituminous coal. The influence of co-firing on fuel preparation and handling, fuel management operations, boiler efficiencies and operating temperatures and the formation and control of airborne emissions was investigated. The tests demonstrated the potential for significant technical, economic and environmental benefits associated with wood co-firing, including improving dust control during fuel handling,