To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
单级式双有源桥(dual active bridge,DAB)DC/AC变换器控制自由度多,变压器匝比、漏感、开关频率等参数相互耦合,导致变换器效率优化面临多重制约。该文分析变压器匝比、漏感与软开关范围、漏感电流有效值、漏感电流峰值之间的约束关系,...单级式双有源桥(dual active bridge,DAB)DC/AC变换器控制自由度多,变压器匝比、漏感、开关频率等参数相互耦合,导致变换器效率优化面临多重制约。该文分析变压器匝比、漏感与软开关范围、漏感电流有效值、漏感电流峰值之间的约束关系,提出直接表征DAB-DC/AC变换器效率的物理量:效率敏感因子。通过研究效率敏感因子对系统损耗的影响机理,实现变换器效率最优的硬件参数设计,为多参数耦合的单级式DAB-DC/AC变换器效率优化提供理论指导。最后通过一台450 W样机验证所提理论的正确性。展开更多
为解决孤岛模式下交直流混合微电网稳定运行的问题,文中提出一种孤岛交直流混合微电网柔性多状态开关(soft normally open point, SNOP)统一下垂控制策略。该策略基于系统功率平衡关系,通过归一化方法将2条馈线的频率下垂特性和直流电...为解决孤岛模式下交直流混合微电网稳定运行的问题,文中提出一种孤岛交直流混合微电网柔性多状态开关(soft normally open point, SNOP)统一下垂控制策略。该策略基于系统功率平衡关系,通过归一化方法将2条馈线的频率下垂特性和直流电压下垂特性相结合,根据交流频率和直流电压的变化情况,判断系统的运行状态,并通过SNOP统一调节交流子网频率和直流子网电压,使交、直流微电网能够均衡承担系统总功率变化量,从而确保交流频率和直流电压稳定在系统允许范围内。同时,为了优先确保分布式电源的就近消纳,避免SNOP的非必要动作,设计了SNOP的调节死区,使得交、直流微电网能够优先利用各子网内分布式电源,从而减少SNOP交、直流侧功率的频繁交互。最后,通过MATLAB/Simulink仿真验证了所提统一下垂控制策略的有效性。展开更多
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
文摘单级式双有源桥(dual active bridge,DAB)DC/AC变换器控制自由度多,变压器匝比、漏感、开关频率等参数相互耦合,导致变换器效率优化面临多重制约。该文分析变压器匝比、漏感与软开关范围、漏感电流有效值、漏感电流峰值之间的约束关系,提出直接表征DAB-DC/AC变换器效率的物理量:效率敏感因子。通过研究效率敏感因子对系统损耗的影响机理,实现变换器效率最优的硬件参数设计,为多参数耦合的单级式DAB-DC/AC变换器效率优化提供理论指导。最后通过一台450 W样机验证所提理论的正确性。
文摘为解决孤岛模式下交直流混合微电网稳定运行的问题,文中提出一种孤岛交直流混合微电网柔性多状态开关(soft normally open point, SNOP)统一下垂控制策略。该策略基于系统功率平衡关系,通过归一化方法将2条馈线的频率下垂特性和直流电压下垂特性相结合,根据交流频率和直流电压的变化情况,判断系统的运行状态,并通过SNOP统一调节交流子网频率和直流子网电压,使交、直流微电网能够均衡承担系统总功率变化量,从而确保交流频率和直流电压稳定在系统允许范围内。同时,为了优先确保分布式电源的就近消纳,避免SNOP的非必要动作,设计了SNOP的调节死区,使得交、直流微电网能够优先利用各子网内分布式电源,从而减少SNOP交、直流侧功率的频繁交互。最后,通过MATLAB/Simulink仿真验证了所提统一下垂控制策略的有效性。
