In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat...In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat to replace a part or all of the extracted steam in one or more preheating stages. The performance of an SAPG plant with different replacements is investigated in this study by using specific consumption theory(SCT). Fuel-specific and cost-specific consumption models for SAPG plants are built based on the SCT. A typical 330 MW coal-fired power plant is used as the study case. The performance of the SAPG plant in terms of specific consumption, with steam obtained from the first through the eighth(except for the fourth) stages of extraction replaced by solar heat, is compared with that of the reference coal-fired power plant. The fuel-specific consumption of the SAPG plant is determined to be lower than that of the reference coal-fired power plant. The fuel-specific consumption accrual distribution in SAPG plants is used to assess the effect of each individual replacement. Effective strategies to reduce the specific costs of the SAPG and coal-fired power plants are proposed based on the results of this study.展开更多
The conversion of CO_2 to liquid hydrocarbon fuels using solar energy is gaining attraction as a means to deal with climate change and energy depletion,and assessment for related thermochemical cycles has attracted gr...The conversion of CO_2 to liquid hydrocarbon fuels using solar energy is gaining attraction as a means to deal with climate change and energy depletion,and assessment for related thermochemical cycles has attracted great interests in recent years.Here,we perform the thermodynamical analysis on solar-aided CO_2 conversion reactions based on Tin oxides.The equilibrium compositions,production purity and CO_2 conversion are obtained.Also,the variations of conversion efficiency with respect to temperature,normal beam solar insolation,mean flux concentration ratio,initial CO_2 to SnO ratio and heat recuperation percentage are revealed.Our results indicate the initial CO_2 to SnO ratio,χ_(ini),has an evident impact on conversion efficiency andχ_(ini)=0.5,T=700 K andχ_(ini)=1,T=950 K,are favourable for solid C and gaseous CO production,respectively.The calculated maximum cycle efficiency with direct work production is 0.340 at T=950 K andχ_(ini)=1,demonstrating the high conversion efficiency of the proposed system.展开更多
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2015CB251505)the National Natural Science Foundation of China(Grant No.51206049)+2 种基金the National Hi-Tech Research and Development Program of China("863"Project)(2012AA050604)the 111 Project(Grant No.B12034)the Fundamental Research Funds for the Central Universities(Grant No.2014XS29)
文摘In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat to replace a part or all of the extracted steam in one or more preheating stages. The performance of an SAPG plant with different replacements is investigated in this study by using specific consumption theory(SCT). Fuel-specific and cost-specific consumption models for SAPG plants are built based on the SCT. A typical 330 MW coal-fired power plant is used as the study case. The performance of the SAPG plant in terms of specific consumption, with steam obtained from the first through the eighth(except for the fourth) stages of extraction replaced by solar heat, is compared with that of the reference coal-fired power plant. The fuel-specific consumption of the SAPG plant is determined to be lower than that of the reference coal-fired power plant. The fuel-specific consumption accrual distribution in SAPG plants is used to assess the effect of each individual replacement. Effective strategies to reduce the specific costs of the SAPG and coal-fired power plants are proposed based on the results of this study.
基金supported by the National Natural Science Foundation of China (Grant No. 51476163)the Institute of Electrical Engineering, Chinese Academy of Sciences (Grant No. Y770111CSC)
文摘The conversion of CO_2 to liquid hydrocarbon fuels using solar energy is gaining attraction as a means to deal with climate change and energy depletion,and assessment for related thermochemical cycles has attracted great interests in recent years.Here,we perform the thermodynamical analysis on solar-aided CO_2 conversion reactions based on Tin oxides.The equilibrium compositions,production purity and CO_2 conversion are obtained.Also,the variations of conversion efficiency with respect to temperature,normal beam solar insolation,mean flux concentration ratio,initial CO_2 to SnO ratio and heat recuperation percentage are revealed.Our results indicate the initial CO_2 to SnO ratio,χ_(ini),has an evident impact on conversion efficiency andχ_(ini)=0.5,T=700 K andχ_(ini)=1,T=950 K,are favourable for solid C and gaseous CO production,respectively.The calculated maximum cycle efficiency with direct work production is 0.340 at T=950 K andχ_(ini)=1,demonstrating the high conversion efficiency of the proposed system.
