1 ABSTRACT To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One way to do this is to increase the efficiency of electricity production from fossil fuels.This will in t...1 ABSTRACT To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One way to do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce the amount of CO2emissions for a given power output.Using US practice for efficiency calculations,then a move from a typical US plant running at 37%efficiency to a 760℃/38.5 MPa(1 400/5 580 psi)plant running at 48%efficiency would reduce CO2emissions by 170kg/MW.hr or 25%.展开更多
Efficient power generation and transmission
Efficient power generation involves converting as much of the primary energy used in a power plant as possible into electricity and usable heat. Increasing efficiency in fo...Efficient power generation and transmission
Efficient power generation involves converting as much of the primary energy used in a power plant as possible into electricity and usable heat. Increasing efficiency in fossil fuel power plants by just a few percentage points can save substantial resources and significantly decrease CO2 emissions. In case of renewable energy sources, the effi- ciency determines the costs of energy generation and thereby how competitive they are compared to conventional power plants.展开更多
(Continued from the previous issue)Brush Seals:Far better leakage reductions can be achieved by using brush seals,which provide a curtain of metal bristles between adjacent areas of different pressure(Figure 12).Since...(Continued from the previous issue)Brush Seals:Far better leakage reductions can be achieved by using brush seals,which provide a curtain of metal bristles between adjacent areas of different pressure(Figure 12).Since the bristles are canted at an angle relative to the radial direction of the shaft,the seal closes as soon as pressure is applied and even if the brush seal展开更多
(Continued from the previous issue)Power to drive the shuttle and its aircraft load comes from expanding steam piped to the catapult from the main steam system(Figure 3.8.2).This steam is placed under pressure in larg...(Continued from the previous issue)Power to drive the shuttle and its aircraft load comes from expanding steam piped to the catapult from the main steam system(Figure 3.8.2).This steam is placed under pressure in large tanks(called accumulators or receivers)located under the launching engine.Steam is admitted to the receivers through the flow control valve(sometimes called steam charging valves).From the receivers,the steam is transferred at the moment of launch into the power cylinders.Steam acts directly on the pistons and propels the piston-shuttle assembly through the cylinders.展开更多
To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One wayto do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce t...To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One wayto do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce the amountof CO2emissions for a given power output.Using US practice展开更多
(Continued from the previous issue)This clearly indicates that the overall loss can be most easily reduced by reducing the profile loss throughout the entire turbine.The secondary flow loss is of significance for thos...(Continued from the previous issue)This clearly indicates that the overall loss can be most easily reduced by reducing the profile loss throughout the entire turbine.The secondary flow loss is of significance for those stages that are characterized by a low aspect ratio(ratio of blade height to blade chord),i.e.the front stages of the HP and IP turbine component.Leakage losses are relatively high in the admission sections to the HP and IP turbines.In general,the flow field in steam turbines is,at least to some extent,characterized by fully three-dimensional effects.This is particularly true for low aspect ratio turbines there the secondary flows generated close to the展开更多
During the normal operation of a nuclear reactor,the nuclear fuel in the reactor’s core,the fissionable material,usually uranium or plutonium,is continuously being consumed and depleted,requiring periodic refueling.
Fuel cells use basic fuels including natural gas and biogas to electrochemically generate electricity,and can produce electricity continuously as long as fuel and air/oxygen are supplied.Each fuel cell is capable of p...Fuel cells use basic fuels including natural gas and biogas to electrochemically generate electricity,and can produce electricity continuously as long as fuel and air/oxygen are supplied.Each fuel cell is capable of producing several watts of electricity. When multiple cells are interleaved together with the interconnecting plates,more power can be obtained. Multiple batteries together form so called power module.展开更多
In an effort for the deep-space travel,like landing humans on Mars,National Aeronautics and Space Administration(NASA)awarded an$18.8 million contract to BWXT Nuclear Energy Inc.in 2017,to design a reactor and develop...In an effort for the deep-space travel,like landing humans on Mars,National Aeronautics and Space Administration(NASA)awarded an$18.8 million contract to BWXT Nuclear Energy Inc.in 2017,to design a reactor and develop fuel for use in a nuclear-thermal propulsion engine.The atomic system,different from the conventional rockets burning fuel to create thrust,instead uses the展开更多
NASA and Lockheed Martin have been working on an airplane design that could fly faster than the speed of sound and also fix the Concorde's biggest problem,the sonic boom,that is,the terrifying house-rattling noise...NASA and Lockheed Martin have been working on an airplane design that could fly faster than the speed of sound and also fix the Concorde's biggest problem,the sonic boom,that is,the terrifying house-rattling noise.The Concorde,one of only two faster-than-sound aircraft to ever carry paying passengers,was one of mankind's greatest aeronautic achievements.It still holds the Guinness World Record for fastest commercial flight across展开更多
Wind energy has often been touted as one of the most reliable sources of renewable energy.Substantial efforts have been made to harness this awesome power of nature.The designs of wind turbines have evolved over the y...Wind energy has often been touted as one of the most reliable sources of renewable energy.Substantial efforts have been made to harness this awesome power of nature.The designs of wind turbines have evolved over the years,展开更多
The Fukushima disaster in Japan in 2011 effectively brought a global nuclear boom to a halt.Countries like Sweden,Switzerland and Germany are continuing to phase out nuclear generation to an extent that more plants ha...The Fukushima disaster in Japan in 2011 effectively brought a global nuclear boom to a halt.Countries like Sweden,Switzerland and Germany are continuing to phase out nuclear generation to an extent that more plants have closed than opened in recent years.Britain and Belgium have recently switched off several ageing reactors over safe-展开更多
文摘1 ABSTRACT To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One way to do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce the amount of CO2emissions for a given power output.Using US practice for efficiency calculations,then a move from a typical US plant running at 37%efficiency to a 760℃/38.5 MPa(1 400/5 580 psi)plant running at 48%efficiency would reduce CO2emissions by 170kg/MW.hr or 25%.
文摘Efficient power generation and transmission
Efficient power generation involves converting as much of the primary energy used in a power plant as possible into electricity and usable heat. Increasing efficiency in fossil fuel power plants by just a few percentage points can save substantial resources and significantly decrease CO2 emissions. In case of renewable energy sources, the effi- ciency determines the costs of energy generation and thereby how competitive they are compared to conventional power plants.
文摘(Continued from the previous issue)Brush Seals:Far better leakage reductions can be achieved by using brush seals,which provide a curtain of metal bristles between adjacent areas of different pressure(Figure 12).Since the bristles are canted at an angle relative to the radial direction of the shaft,the seal closes as soon as pressure is applied and even if the brush seal
文摘(Continued from the previous issue)Power to drive the shuttle and its aircraft load comes from expanding steam piped to the catapult from the main steam system(Figure 3.8.2).This steam is placed under pressure in large tanks(called accumulators or receivers)located under the launching engine.Steam is admitted to the receivers through the flow control valve(sometimes called steam charging valves).From the receivers,the steam is transferred at the moment of launch into the power cylinders.Steam acts directly on the pistons and propels the piston-shuttle assembly through the cylinders.
文摘To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One wayto do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce the amountof CO2emissions for a given power output.Using US practice
文摘(Continued from the previous issue)This clearly indicates that the overall loss can be most easily reduced by reducing the profile loss throughout the entire turbine.The secondary flow loss is of significance for those stages that are characterized by a low aspect ratio(ratio of blade height to blade chord),i.e.the front stages of the HP and IP turbine component.Leakage losses are relatively high in the admission sections to the HP and IP turbines.In general,the flow field in steam turbines is,at least to some extent,characterized by fully three-dimensional effects.This is particularly true for low aspect ratio turbines there the secondary flows generated close to the
文摘During the normal operation of a nuclear reactor,the nuclear fuel in the reactor’s core,the fissionable material,usually uranium or plutonium,is continuously being consumed and depleted,requiring periodic refueling.
文摘Fuel cells use basic fuels including natural gas and biogas to electrochemically generate electricity,and can produce electricity continuously as long as fuel and air/oxygen are supplied.Each fuel cell is capable of producing several watts of electricity. When multiple cells are interleaved together with the interconnecting plates,more power can be obtained. Multiple batteries together form so called power module.
文摘In an effort for the deep-space travel,like landing humans on Mars,National Aeronautics and Space Administration(NASA)awarded an$18.8 million contract to BWXT Nuclear Energy Inc.in 2017,to design a reactor and develop fuel for use in a nuclear-thermal propulsion engine.The atomic system,different from the conventional rockets burning fuel to create thrust,instead uses the
文摘NASA and Lockheed Martin have been working on an airplane design that could fly faster than the speed of sound and also fix the Concorde's biggest problem,the sonic boom,that is,the terrifying house-rattling noise.The Concorde,one of only two faster-than-sound aircraft to ever carry paying passengers,was one of mankind's greatest aeronautic achievements.It still holds the Guinness World Record for fastest commercial flight across
文摘Wind energy has often been touted as one of the most reliable sources of renewable energy.Substantial efforts have been made to harness this awesome power of nature.The designs of wind turbines have evolved over the years,
文摘The Fukushima disaster in Japan in 2011 effectively brought a global nuclear boom to a halt.Countries like Sweden,Switzerland and Germany are continuing to phase out nuclear generation to an extent that more plants have closed than opened in recent years.Britain and Belgium have recently switched off several ageing reactors over safe-
