太阳能与燃煤互补发电方式是近年来大规模太阳能热利用的发展方向之一。以槽式太阳能集热系统辅助某330MW燃煤机组替代高加回热抽汽加热给水的互补发电系统为例,对功率不变型互补发电系统的设计点热力性能及年热力性能进行了分析。结果...太阳能与燃煤互补发电方式是近年来大规模太阳能热利用的发展方向之一。以槽式太阳能集热系统辅助某330MW燃煤机组替代高加回热抽汽加热给水的互补发电系统为例,对功率不变型互补发电系统的设计点热力性能及年热力性能进行了分析。结果表明,太阳能辅助发电系统的年光电转换效率可达到20.41%,高于单纯槽式太阳能热发电方式。在此基础上,以内部收益率(internal rate of return,IRR)作为评价指标,运用技术经济的基本原理对太阳能辅助燃煤机组互补发电系统的经济性能及其主要影响因素进行了定量的分析评价,得到了太阳能上网电价、集热器造价、燃料成本等关键因素对内部收益率的影响。展开更多
为提高太阳能水源热泵耦合系统性能,该文从设计及运行两方面对其进行优化研究。在建立太阳能水源热泵耦合系统应用模型的基础上,用瞬时系统模拟程序(Transient system simulation program,TRNSYS)软件搭建系统计算模型,以系统的设计参数...为提高太阳能水源热泵耦合系统性能,该文从设计及运行两方面对其进行优化研究。在建立太阳能水源热泵耦合系统应用模型的基础上,用瞬时系统模拟程序(Transient system simulation program,TRNSYS)软件搭建系统计算模型,以系统的设计参数如:太阳能集热器面积、储热水箱体积及集热器倾角等为变量,利用GENOPT软件对系统进行优化。并以系统运行控制参数如:集热器供回水温差和供暖末端供回水温差为变量分析系统性能参数(Coefficient of performance,COP),分析系统节能潜力。该文以北京某别墅为研究对象进行优化,结果表明系统COP升高、性能得到改善。研究结果为太阳能热泵系统优化提供了一定的理论依据。展开更多
Lithium metal has been regarded as the ultimate anode for next-generation rechargeable batteries with high energy density.However,its high reactivity and dendrite growth seriously limit its commercial application,whic...Lithium metal has been regarded as the ultimate anode for next-generation rechargeable batteries with high energy density.However,its high reactivity and dendrite growth seriously limit its commercial application,which can be well addressed by realizing uniform Li deposition.Here,we report a facile and scalable one-step vulcanization method to modify commercial Cu foil with lithophilic Cu2S.The in situ formed Cu2S layer can not only promote the homogeneous deposition of Li via its lithophilic nature,but also benefit the formation of a stable solid-electrolyte interphase during initial activation.The Cu2S-modified Cu current collector realizes dendrite-free Li plating/stripping and thus exhibits stable cycling performance with a high Coulombic efficiency,even with a large capacity of 4 mA h cm^-2.A full-cell consisting of a Cu2S/Cu-Li anode and a LiFePO4 cathode exhibits greatly improved cycling stability and enhanced Coulombic efficiency,demonstrating the effectiveness and practicability of the proposed Cu2S/Cu foil in the field of rechargeable Li metal batteries.展开更多
文摘太阳能与燃煤互补发电方式是近年来大规模太阳能热利用的发展方向之一。以槽式太阳能集热系统辅助某330MW燃煤机组替代高加回热抽汽加热给水的互补发电系统为例,对功率不变型互补发电系统的设计点热力性能及年热力性能进行了分析。结果表明,太阳能辅助发电系统的年光电转换效率可达到20.41%,高于单纯槽式太阳能热发电方式。在此基础上,以内部收益率(internal rate of return,IRR)作为评价指标,运用技术经济的基本原理对太阳能辅助燃煤机组互补发电系统的经济性能及其主要影响因素进行了定量的分析评价,得到了太阳能上网电价、集热器造价、燃料成本等关键因素对内部收益率的影响。
文摘为提高太阳能水源热泵耦合系统性能,该文从设计及运行两方面对其进行优化研究。在建立太阳能水源热泵耦合系统应用模型的基础上,用瞬时系统模拟程序(Transient system simulation program,TRNSYS)软件搭建系统计算模型,以系统的设计参数如:太阳能集热器面积、储热水箱体积及集热器倾角等为变量,利用GENOPT软件对系统进行优化。并以系统运行控制参数如:集热器供回水温差和供暖末端供回水温差为变量分析系统性能参数(Coefficient of performance,COP),分析系统节能潜力。该文以北京某别墅为研究对象进行优化,结果表明系统COP升高、性能得到改善。研究结果为太阳能热泵系统优化提供了一定的理论依据。
基金supported by the National Key R&D Program of China(2018YFB0905400)the National Natural Science Foundation of China(51632001 and 51972131)Chinese Postdoctoral Science Foundation。
文摘Lithium metal has been regarded as the ultimate anode for next-generation rechargeable batteries with high energy density.However,its high reactivity and dendrite growth seriously limit its commercial application,which can be well addressed by realizing uniform Li deposition.Here,we report a facile and scalable one-step vulcanization method to modify commercial Cu foil with lithophilic Cu2S.The in situ formed Cu2S layer can not only promote the homogeneous deposition of Li via its lithophilic nature,but also benefit the formation of a stable solid-electrolyte interphase during initial activation.The Cu2S-modified Cu current collector realizes dendrite-free Li plating/stripping and thus exhibits stable cycling performance with a high Coulombic efficiency,even with a large capacity of 4 mA h cm^-2.A full-cell consisting of a Cu2S/Cu-Li anode and a LiFePO4 cathode exhibits greatly improved cycling stability and enhanced Coulombic efficiency,demonstrating the effectiveness and practicability of the proposed Cu2S/Cu foil in the field of rechargeable Li metal batteries.
