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02076 Economic control for generation in thermal power systems
06
Electrical power supply and utilization (economics, policy, supplies, forecasts)
labyrinth nature of the pore systems of supported electrodes complicated stripping measurements and called into question the benefit of using RDEs for porous electrodes due to undefinable mass transport conditions within the electrode.
Economics,
99102076
Economic
Policy, Supplies,
Forecasts
control for generation in thermal power
systems Salama, M. M. Energy Conversion and Management, 1999, 40, (6) 669681. Two mathematical models were built, based on two proposed procedures for scheduling of generating units to obtain optimum economic dispatch with consideration of control over the generating units. The steady state deviations in each model of frequency, mechanical power, electrical power and transmission losses in addition to outputs of generating units and the corresponding generation costs were analysed, in each time interval, after the occurrence of the load change and damping of all synchronizing oscillations. The load change in each time interval has been taken, in the first model, as the difference between the value of the load in the present interval and its value in the previous one. In the second model it has been taken, optionally, as a certain specified constant value.
The efficient use of electricity in Brazil: progress and opportunities
99102077
Geller, H. et al. Energy Policy, 1998, 26, (II), 859-872. The efforts recently made with electricity conservation and DSM programmes in Brazil are reviewed here. The principal end uses in the residential, commercial and industrial sectors are considered. The status of various electricity-saving measures is examined along with initiatives developed by the National Electricity Conservation Program (PROCEL), utilities and other agencies. While some progress has been made, there remains enormous potential for cost-effective efficiency improvements. A discussion of strategies for intensifying electricity conservation efforts in the future is presented.
Fault analysis of a diagonal type MHD generator controlled with local control circuit
99102076
Ishikawa, M. et al. Energy Convers. Manage., 1999, 40, (3), 249-260. A coal-fired supersonic diagonal channel which suffers from faults of external control circuits was the subject of the study. Its behaviour under electrical non-uniformities caused by coal slag polarization were investigated. The channel designed for a pilot-plant is controlled with external circuits, such as master/slave current controller and consolidation circuits and is connected to the A.C. grid through double-bridge line-commutated inverters. A simultaneous analysis of the magneto-hydrodynamic (MHD) channel and external circuits was performed with a two-dimensional equivalent circuit method and time-dependent one-dimensional gas dynamic equations. The short fault of switching device of both current control and consolidation circuits was found to have only a small influence on performance and no countermeasure is required. Furthermore, when a switching device of the master/slave current consolidation circuit is assumed not to fire, the loading current leads to zero in about 20 ms, with the flow field of the MHD channel being largely influenced and the designed supersonic flow is decelerated to subsonic flow through the shock wave. It is also shown that, if the faulted switching device can be quickly shorted, the whole flow field recovers to the normal condition. It is therefore necessary to install some fast protection systems.
Impact of coal preparation on the environmental management and economics of power generation in India
99102079
Gellakota, S. et al. Proc., Annu. Meet. Air Waste Manage. Assoc., 1997, 90, WA9201, l-12. In India, because of increasing demand for additional coal-based generation capacity, especially near urban areas, the management of air quality and solid waste has become an important environmental and economic issue. Major non-coking coal mines, located in the central and eastern India, necessitate transportation of a large amount of high-ash coal (4050%) over 1000 km to power plants located near urban areas. Based on projected demand for coal-based generating capacity, it is estimated that, if no control measures are taken now, more than 80 million tonnes of ash will be produced annually near urban areas by 2010. Such a large quantity of ash not only overloads control systems to increase particulate emissions but also requires a large land filling space. Under the Indo-US coal preparation programme, the US Department of Energy’s Federal Energy Technology Center (FETC) is coordinating USAID’s coal preparation activities in India for improved power generation. This paper addresses the current activities of this programme, effective strategies for coal preparation and their impact on the economics of infrastructure, environmental management and power generation.
99lO2060 Optimal fuel cell system design considering functional performance and production costs Xue, D. and Dong, 2. .I. of Power Sources, 1998, 76, (l), 69-80. The optimization-based, integrated concurrent design method was applied to the modelling, analysis and design of a transportation fuel cell system. The first section of this paper introduces a general optimal design model considering both functional performance and production costs. The study then explores the intrinsic relations among various fuel cell system performance and cost aspects by using the Ballard Mark V Transit Bus fuel cell system as an example, thus providing insights for new cost-effective designs. A joint performance and cost optimization is carried out to demonstrate this new approach. This approach breaks the traditional barrier between design (concerning functional performance) and manufacturing (concerning production costs), allowing both functional performance and production costs to be fed into design phase and to be jointly optimized. 99102061
Predicting life of skirt supports in pressurized reactors under cyclic conditions
Sugaya, M. et al. Prepr. Symp. Am. Chem. Sot., Div. Fuel Chem., 1998, 43, (3), 635-639. The occurrence of cracks originating at the outer boundaries of the welded junction is a common problem with skirt support. In order to understand the background on this, a study of the changes in temperatures and stress profiles has been undertaken by placing strain gauges and thermocouples near the attachment region of an existing delayed coking reactor. In order to provide a basis for validating models of stress failure, stresses arising from the differential thermal expansion, junction momentum and other contributions have been examined in terms of the Weil-Murphy analysis. 99102062 Savannah Electric Plant Mcintosh Unit #l precipitator rebuild project. Meeting the demands of a changing utility market Daniel, J. and Wagner, M. Proc. Am. Power Conf., 1998, 60, (I), 167-172. The oroiect at Savannah Electric’s Plant Macintosh Unit #I that successfully achieved the dual objectives of environmental compliance while reducing production costs is reviewed in this paper. This is made possible by utilizing a cost effective ESP design, a customized discharge electrode configuration and a dual flue gas conditioning system. Aspects of this project included: (1) Increased plate spacing from 9 to 11.25 inches with new TR sets for increased voltage levels. (2) Replaced weighted wires and crimp lock plates with special RDEs and G-opzel plates to optimize corona discharge and uniformity. (3) Maximum utilization of existing configuration for cost reduction. (4) SO3 and NH3 conditioning for enhanced fly ash collection. (5) State of the art data management system. (6) Customized rigid discharge electrodes to optimize six characteristics for each field. The paper details the attempts of plate straightening precluding the decision to rebuild the ESP and presents some detail on the selection and implementation of the design choices made to meet Savannah Electric’s objectives. The ESP’s performance is compared by burning a ‘quality challenged’, low moisture, high resistivity ash coal with approximately 92% (AlzOs + SiOz) in the ash. The successful completion of this project has enabled Plant McIntosh’s Unit #l to cost competitively meet the rigorous demands of the new utility marketplace of the next millennium.
Technical and economic aspects of electron beam installations for treatment of flue gases from power plants
99102063
Chmielewski, A. G. et al. Radiat. Technol. Conserv. Environ., Proc. Symp., 1997 (Pub. 1998), 133-143. Concern is mounting over the emission of environmental pollutants such as SOz and NO, into the atmosphere from heavy industrial activity and in particular from fossil fuel burning in electricity production. One of the three areas of the world most affected by the resultant acid rain lies in eastern and central Europe and includes Poland, parts of Germany, the Czech Republic and Slovakia. A major contribution to this pollution comes from the burning of poor quality pit and brown coal with a high sulfur content. These effects, as well as that of polluted air reaching Poland from other countries, have begun to damage forests and cause public health concerns in regions of high industrial density. Many countries around the world have started to impose industrial emission limits and this move has generated renewed interest in finding viable and cost effective solutions to SOz and NO, pollution control. The conventional technologies - wet scrubbing for SOz and selective catalytic reduction for NOx have now reached their full potential and these methods are not expected to provide further improvements in terms of efficiency or reduction in construction costs. New technologies are being investigated for industrial scale commercial viability. One of them is the electron beam dry scrubbing process, which allows the simultaneous removal of SOz and NO, from industrial flue gases and the economical aspects of this technology are discussed here.
Technological requirements for the UK clean coal power industry
99102064
Chakraborty, R. K. and West, S. S. AEA Technol., [Rep.] AEAT, 1997, (AEAT-2013), (i-v), I-16. The technology needs of the clean coal power generation sector in the UK are reviewed. The aim of this report is to highlight target areas for future research and development in the context of market exploitation of these technologies. The world-wide market for power generation is expected to
Fuel and Energy Abstracts
May 1999 213
Electrical power supply and utilization (economics, policy, supplies, forecasts)
labyrinth nature of the pore systems of supported electrodes complicated stripping measurements and called into question the benefit of using RDEs for porous electrodes due to undefinable mass transport conditions within the electrode.
Economics,
99102076
Economic
Policy, Supplies,
Forecasts
control for generation in thermal power
systems Salama, M. M. Energy Conversion and Management, 1999, 40, (6) 669681. Two mathematical models were built, based on two proposed procedures for scheduling of generating units to obtain optimum economic dispatch with consideration of control over the generating units. The steady state deviations in each model of frequency, mechanical power, electrical power and transmission losses in addition to outputs of generating units and the corresponding generation costs were analysed, in each time interval, after the occurrence of the load change and damping of all synchronizing oscillations. The load change in each time interval has been taken, in the first model, as the difference between the value of the load in the present interval and its value in the previous one. In the second model it has been taken, optionally, as a certain specified constant value.
The efficient use of electricity in Brazil: progress and opportunities
99102077
Geller, H. et al. Energy Policy, 1998, 26, (II), 859-872. The efforts recently made with electricity conservation and DSM programmes in Brazil are reviewed here. The principal end uses in the residential, commercial and industrial sectors are considered. The status of various electricity-saving measures is examined along with initiatives developed by the National Electricity Conservation Program (PROCEL), utilities and other agencies. While some progress has been made, there remains enormous potential for cost-effective efficiency improvements. A discussion of strategies for intensifying electricity conservation efforts in the future is presented.
Fault analysis of a diagonal type MHD generator controlled with local control circuit
99102076
Ishikawa, M. et al. Energy Convers. Manage., 1999, 40, (3), 249-260. A coal-fired supersonic diagonal channel which suffers from faults of external control circuits was the subject of the study. Its behaviour under electrical non-uniformities caused by coal slag polarization were investigated. The channel designed for a pilot-plant is controlled with external circuits, such as master/slave current controller and consolidation circuits and is connected to the A.C. grid through double-bridge line-commutated inverters. A simultaneous analysis of the magneto-hydrodynamic (MHD) channel and external circuits was performed with a two-dimensional equivalent circuit method and time-dependent one-dimensional gas dynamic equations. The short fault of switching device of both current control and consolidation circuits was found to have only a small influence on performance and no countermeasure is required. Furthermore, when a switching device of the master/slave current consolidation circuit is assumed not to fire, the loading current leads to zero in about 20 ms, with the flow field of the MHD channel being largely influenced and the designed supersonic flow is decelerated to subsonic flow through the shock wave. It is also shown that, if the faulted switching device can be quickly shorted, the whole flow field recovers to the normal condition. It is therefore necessary to install some fast protection systems.
Impact of coal preparation on the environmental management and economics of power generation in India
99102079
Gellakota, S. et al. Proc., Annu. Meet. Air Waste Manage. Assoc., 1997, 90, WA9201, l-12. In India, because of increasing demand for additional coal-based generation capacity, especially near urban areas, the management of air quality and solid waste has become an important environmental and economic issue. Major non-coking coal mines, located in the central and eastern India, necessitate transportation of a large amount of high-ash coal (4050%) over 1000 km to power plants located near urban areas. Based on projected demand for coal-based generating capacity, it is estimated that, if no control measures are taken now, more than 80 million tonnes of ash will be produced annually near urban areas by 2010. Such a large quantity of ash not only overloads control systems to increase particulate emissions but also requires a large land filling space. Under the Indo-US coal preparation programme, the US Department of Energy’s Federal Energy Technology Center (FETC) is coordinating USAID’s coal preparation activities in India for improved power generation. This paper addresses the current activities of this programme, effective strategies for coal preparation and their impact on the economics of infrastructure, environmental management and power generation.
99lO2060 Optimal fuel cell system design considering functional performance and production costs Xue, D. and Dong, 2. .I. of Power Sources, 1998, 76, (l), 69-80. The optimization-based, integrated concurrent design method was applied to the modelling, analysis and design of a transportation fuel cell system. The first section of this paper introduces a general optimal design model considering both functional performance and production costs. The study then explores the intrinsic relations among various fuel cell system performance and cost aspects by using the Ballard Mark V Transit Bus fuel cell system as an example, thus providing insights for new cost-effective designs. A joint performance and cost optimization is carried out to demonstrate this new approach. This approach breaks the traditional barrier between design (concerning functional performance) and manufacturing (concerning production costs), allowing both functional performance and production costs to be fed into design phase and to be jointly optimized. 99102061
Predicting life of skirt supports in pressurized reactors under cyclic conditions
Sugaya, M. et al. Prepr. Symp. Am. Chem. Sot., Div. Fuel Chem., 1998, 43, (3), 635-639. The occurrence of cracks originating at the outer boundaries of the welded junction is a common problem with skirt support. In order to understand the background on this, a study of the changes in temperatures and stress profiles has been undertaken by placing strain gauges and thermocouples near the attachment region of an existing delayed coking reactor. In order to provide a basis for validating models of stress failure, stresses arising from the differential thermal expansion, junction momentum and other contributions have been examined in terms of the Weil-Murphy analysis. 99102062 Savannah Electric Plant Mcintosh Unit #l precipitator rebuild project. Meeting the demands of a changing utility market Daniel, J. and Wagner, M. Proc. Am. Power Conf., 1998, 60, (I), 167-172. The oroiect at Savannah Electric’s Plant Macintosh Unit #I that successfully achieved the dual objectives of environmental compliance while reducing production costs is reviewed in this paper. This is made possible by utilizing a cost effective ESP design, a customized discharge electrode configuration and a dual flue gas conditioning system. Aspects of this project included: (1) Increased plate spacing from 9 to 11.25 inches with new TR sets for increased voltage levels. (2) Replaced weighted wires and crimp lock plates with special RDEs and G-opzel plates to optimize corona discharge and uniformity. (3) Maximum utilization of existing configuration for cost reduction. (4) SO3 and NH3 conditioning for enhanced fly ash collection. (5) State of the art data management system. (6) Customized rigid discharge electrodes to optimize six characteristics for each field. The paper details the attempts of plate straightening precluding the decision to rebuild the ESP and presents some detail on the selection and implementation of the design choices made to meet Savannah Electric’s objectives. The ESP’s performance is compared by burning a ‘quality challenged’, low moisture, high resistivity ash coal with approximately 92% (AlzOs + SiOz) in the ash. The successful completion of this project has enabled Plant McIntosh’s Unit #l to cost competitively meet the rigorous demands of the new utility marketplace of the next millennium.
Technical and economic aspects of electron beam installations for treatment of flue gases from power plants
99102063
Chmielewski, A. G. et al. Radiat. Technol. Conserv. Environ., Proc. Symp., 1997 (Pub. 1998), 133-143. Concern is mounting over the emission of environmental pollutants such as SOz and NO, into the atmosphere from heavy industrial activity and in particular from fossil fuel burning in electricity production. One of the three areas of the world most affected by the resultant acid rain lies in eastern and central Europe and includes Poland, parts of Germany, the Czech Republic and Slovakia. A major contribution to this pollution comes from the burning of poor quality pit and brown coal with a high sulfur content. These effects, as well as that of polluted air reaching Poland from other countries, have begun to damage forests and cause public health concerns in regions of high industrial density. Many countries around the world have started to impose industrial emission limits and this move has generated renewed interest in finding viable and cost effective solutions to SOz and NO, pollution control. The conventional technologies - wet scrubbing for SOz and selective catalytic reduction for NOx have now reached their full potential and these methods are not expected to provide further improvements in terms of efficiency or reduction in construction costs. New technologies are being investigated for industrial scale commercial viability. One of them is the electron beam dry scrubbing process, which allows the simultaneous removal of SOz and NO, from industrial flue gases and the economical aspects of this technology are discussed here.
Technological requirements for the UK clean coal power industry
99102064
Chakraborty, R. K. and West, S. S. AEA Technol., [Rep.] AEAT, 1997, (AEAT-2013), (i-v), I-16. The technology needs of the clean coal power generation sector in the UK are reviewed. The aim of this report is to highlight target areas for future research and development in the context of market exploitation of these technologies. The world-wide market for power generation is expected to
Fuel and Energy Abstracts
May 1999 213