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Beam Scheduling with Various Mission Demands in Data Relay Satellite Systems

Journal of Communications and Information Networks 2021年第4期6卷 396-410页

作者： boyu deng Chunxiao Jiang Jingchao Wang Linling Kuang The Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Tsinghua Space Center Tsinghua UniversityBeijing 100084China Peng Cheng Laboratory Shenzhen 518055China

Beam scheduling is one of the most important issues regarding data relay satellite systems,which can improve the utilization efficiency of limited system resources by programming beam allocation for relay *** ever-increasing relay missions create a substantial challenge for beam scheduling due to an increase in different mission *** cooperative usage of different beams further increases the complexity of this ***,we develop a novel optimization method to solve the beam scheduling problem for the scenario of various mission demands in the data relay satellite system(DRSS).Based on the analysis of mission demands and resource features,we first construct a heterogeneous parallel machines scheduling model to formulate the beam scheduling problem in the *** solve this complicated model,we investigate the matching method between mission demands and beam resources,and introduce two concepts,the loose duration and the number of available beams,to make the matching process more ***,the following three algorithms are *** first approach,the maximized completion probability algorithm(MCPA),applies a greedy strategy based on the new concepts to allocate beams for missions;and two improved versions of this algorithm are also presented,which employ the strategies of mission insertion optimization and mission sequence optimization,*** simulation results show that the proposed algorithms are superior to the existing algorithms in terms of the scheduled missions,the weight of scheduled missions,and the processing time,which significantly improves the performance of beam scheduling in the DRSS.

关键词： DRSS beam scheduling various mission demands loose duration available beams greedy algorithm

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Analysis and Referential Significance of a Breakdown Accident of the Main Feed Water Pump in a 350 MW Supercritical CFB Boiler

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Journal of Thermal Science 2023年第5期32卷 1797-1806页

作者： deng boyu ZHANG Man WEI Guohua LYU Junfu YANG Hairui State Key Laboratory of Power System and Generation Equipment Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Efficient and Clean Coal-fired Utility Boilers/Harbin Boiler Company Limited Harbin 150046China

Controversies still exist over the necessity of equipping with an emergency water supply system in the supercritical circulating fluidized bed/CFB *** resolve the dispute,research on the safety of the heating surfaces in the supercritical CFB boiler during the electricity failure accident under the assumption of not putting the emergency water supply system into use must be ***,due to the low incidence rate of this accident,no relevant data have been reported *** provide useful data for the related research,a breakdown accident of the main feed water pump that happened in a 350 MW supercritical CFB boiler was introduced in this *** analysis of the physical processes in both the furnace and water side of the boiler during this accident was *** the discussion on the similarities and discrepancies between the two accidents was carried *** was found out that with appropriate handling,the data collected in two periods of the breakdown accident of the main feed water pump can provide a reference for the verification of the prediction model of the electricity failure ***,a preliminary prediction model was established as the first step of the verification work.

关键词： supercritical CFB water supply cut off electricity failure accident analysis

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A Fast and Accurate LEO Satellite-Based Direct Position Determination Assisted by TDOA Measurements

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China Communications 2022年第1期19卷 92-103页

作者： Shijie Li Qianyun Zhang boyu deng Biyi Wu Yue Gao School of Cyber Science and Technology BeiHang UniversityBeijing 100191China Tsinghua University ChinaBeijing 100084China Beijing Institute of Technology Beijing 100081China School of Computer Science Fudan University Shanghai 200433China

This paper focuses on the trusted vessel position acquisition using passive localization based on the booming low-earth-orbit(LEO) satellites. As the high signal-to-noise ratio(SNR) reception cannot always be guaranteed at LEO satellites, the recently developed direct position determination(DPD)is adopted. For LEO satellite-based passive localization systems, an efficient DPD is challenging due to the excessive exhaustive search range leading from broad satellite coverage. In order to reduce the computational complexity, we propose a time difference of arrival-assisted DPD(TA-DPD) which minimizes the searching area by the time difference of arrival measurements and their variances. In this way, the size of the searching area is determined by both geometrical constraints and qualities of received signals, and signals with higher SNRs can be positioned more efficiently as their searching areas are generally *** two-dimensional and three-dimensional passive localization simulations using the proposed TA-DPD are provided to demonstrate its efficiency and validity. The superior accuracy performance of the proposed method, especially at low SNRs conditions, is also verified through the comparison to conventional two-step methods. Providing a larger margin in link budget for satellite-based vessel location acquisition,the TA-DPD can be a competitive candidate for trusted marine location service.

关键词： direct position determination LEO satellite constellation passive localization TDOA

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Restart-up Performance of a CFB Boiler after a Sudden Power Failure Accident

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Journal of Thermal Science 2022年第3期31卷 830-839页

作者： YAO Yuge JIANG Ling XIAO Huiren deng boyu ZHANG Man ZHANG Yang YANG Hairui LYU Junfu Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing100084China

Due to the massive bed materials in its typical main loop,a circulating fluidized bed(CFB)boiler may face greater trouble in operation and restart-up if an unplanned sudden power failure happens in the power *** study aims to explore the restart-up performance of a 170 t/h natural circulation CFB boiler after a sudden power failure and evaluate whether the hot restart-up can be *** heat transfer process after the restoration of the primary air is *** the isothermal property of the bed after the restoration of the power and air supply,the correlation among the accident duration time,bed temperature after the power restores,inlet air temperature,air supply time,and air velocity is *** predicted results indicate that the major influencing factor of the bed temperature during this process is primary air *** provide guidelines for judgment on whether the hot restart-up can be realized,the maximum values of the air supply time and accident duration time for hot restart-up for different types of coals are *** results show both of them have a rapid decrease as the coal ignition temperature in a CFB boiler increases from 450°C to 650°C,which also means that the coal ignition temperature plays a very important role in the restart-up *** on the simulation results of bed temperature during the accident,it is also estimated that the drum level drops by 77.7 mm after 8 hours but still stays in the permissible range.

关键词： CFB boiler sudden power failure restart-up drum level bed temperature

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Effective diffusivity of oxygen in the ash layer of Huadian oil shale semicoke

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Frontiers in Energy 2021年第2期15卷 320-327页

作者： Yiqun HUANG Yiran LI Man ZHANG boyu deng Hao KONG Junfeng WANG Junfu LYU Hairui YANG Lingmei WANG Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education State Key Laboratory of Power SystemsDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Efficient and Clean Coal-fired Utility Boilers(Harbin Boiler Co. Ltd.)Harbin 150046China Department of Automation Shanxi UniversityTaiyuan 030006China

Diffusion of oxygen in the ash layer usually dominated the combustion of oil shale semicoke particles due to the high ash ***,effective diffusivity of oxygen in the ash layer was a crucial parameter worthy of careful *** this paper,the effective diffusivity of oxygen in the ash layer of Huadian oil shale semicoke was measured directly using an improved Wicke-Kallenbach diffusion *** experimental results showed that higher temperature would lead to a higher effective diffusivity and a thicker ash layer had the negative ***,the effective diffusivity along the direction perpendicular to bedding planes was much lower than that along the direction parallel to bedding *** addition,an effective diffusivity model was developed,which could be used to describe the mass transfer of oxygen in the ash layer of oil shale semicoke.

关键词： oil shale semicoke diffusivity pore structure ash layer

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A state-of-the-art review on transition between the fast fluidization and pneumatic transport of Geldart group B particles

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Particuology 2023年第2期73卷 78-94页

作者： boyu deng Yi Zhang Man Zhang Yi Ding Tuo Zhou Xinhua Yang Zhong Huang Hairui Yang Guangxi Yue State Key Laboratory of Power Systems Department of Energy and Power EngineeringTsinghua UniversityBeijing100084China China Electric Power Planning&Engineering Institute Beijing100120China SDIC Power Holding Co. LtdBeijing100034China

The fluidization state in the circulating fluidized bed(CFB)boiler is crucial to its stable and safe ***,up to now,the research field has not reached unanimity on whether the fluidization regime that the upper furnace of the boiler operates in is the fast fluidization or pneumatic *** this end,this paper reviewed relevant research on the transition between the fast fluidization and pneumatic transport of Geldart group B particles,including the flow characteristics of the fast fluidization,the transition condition between the fast fluidization and pneumatic transport,the determination methods of the transport velocity utr and saturation carrying capacity G_(s)* and the influencing factors on these two *** research findings can provide certain guidelines for the design and optimization of the CFB boiler,and result in plenty of prediction correlations for utr and G_(s)*.Nonetheless,owing to insufficient data available on Geldart group B particles,especially the ones obtained under high temperature or pressure conditions and in large-scale CFB apparatuses,the existing correlations are not well suited for the prediction of u_(tr) and G_(s)* of Geldart group B ***,further efforts are urgently demanded on the fast fluidization transition of Geldart group B particles.

关键词： Fast fluidization transition Transport velocity Saturation carrying capacity Geldart group B particles Circulating fluidized bed

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基于Bayes网络的建筑火灾风险评估模型

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清华大学学报（自然科学版） 2020年第4期60卷 321-327页

作者：疏学明颜峻胡俊吴津津邓博誉清华大学工程物理系公共安全研究院北京100084 安全工程学院中国劳动关系学院北京100048 城市综合应急科学北京市重点实验室北京100084

为评估建筑火灾动态风险,从防火工程的角度将火灾发展过程划分为"火情-火警-火险-火灾"4个阶段,分别研究了不同阶段的主要风险评估参数。采用Bayes网络方法构建了动态风险评估模型,确定了网络结构与参数。采用敏感度分析法研究了评估参... 详细信息

为评估建筑火灾动态风险,从防火工程的角度将火灾发展过程划分为"火情-火警-火险-火灾"4个阶段,分别研究了不同阶段的主要风险评估参数。采用Bayes网络方法构建了动态风险评估模型,确定了网络结构与参数。采用敏感度分析法研究了评估参数对火灾风险的影响程度。以2座典型建筑为例,分别计算得到每个阶段风险和综合风险。研究结果表明:建筑火灾风险是一个动态变化的过程,各阶段风险、评估参数均存在差异;评估节点和依赖关系构成了因果网;评估模型可以有效地将消防监测终端采集的消防大数据与人工智能分析技术相结合,有助于提升建筑消防安全管理的智能化水平。

关键词：安全工程建筑火灾风险评估大数据 Bayes网络

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基于级联SOA结合两级偏移滤波的波长保持型星上全光再生方案

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光学学报 2015年第5期35卷 110-116页

作者：董毅赵尚弘李勇军邓博于空军工程大学信息与导航学院陕西西安710077

针对分布式卫星网络中由于多跳转发导致光信号严重损伤的问题,提出了一种基于级联半导体光放大器(SOA)结合两级偏移滤波结构的波长保持型全光再生方案。该方案利用光脉冲经过不同载流子恢复时间的SOA时频谱展宽方向不同的特点,通过在两... 详细信息

针对分布式卫星网络中由于多跳转发导致光信号严重损伤的问题,提出了一种基于级联半导体光放大器(SOA)结合两级偏移滤波结构的波长保持型全光再生方案。该方案利用光脉冲经过不同载流子恢复时间的SOA时频谱展宽方向不同的特点,通过在两个级联的SOA之后分别进行红移滤波和蓝移滤波,不仅实现了对光信号的两级再生,而且两次偏移滤波产生的波长偏移相互抵消,使再生前后信号的波长保持不变。研究结果表明:再生方案能够有效地抑制信号幅度噪声和功率起伏,信号Q因子改善最高可达到8 d B。

关键词：光通信全光再生自相位调制偏移滤波波长保持 Q因子改善

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失电事故下350MW超临界CFB锅炉水冷壁安全性分析

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中国电机工程学报 2019年第16期39卷 4799-4807页

作者：邓博宇张缦李少华吕俊复杨海瑞电力系统及发电设备控制和仿真国家重点实验室(清华大学) 北京市海淀区100084 中国电力工程顾问集团华北电力设计院有限公司北京市西城区100120

在超临界循环流化床(circulating fluidized bed,CFB)机组上是否需要配备紧急补给水系统一直是业内争议的焦点。针对失电事故下350MW超临界CFB锅炉炉内物理过程的特点,给出安全阀的响应特性模型,建立由质量、能量守恒方程组成的数学模型... 详细信息

在超临界循环流化床(circulating fluidized bed,CFB)机组上是否需要配备紧急补给水系统一直是业内争议的焦点。针对失电事故下350MW超临界CFB锅炉炉内物理过程的特点,给出安全阀的响应特性模型,建立由质量、能量守恒方程组成的数学模型,定量地预测失电事故下水冷壁内工质温度、压力和质量的动态变化过程。同时,通过讨论浇注料、床温及安全阀特性等不同因素对炉内物理过程的影响,对失电事故下350MW超临界CFB锅炉水冷壁的安全性进行了初步的判断,进而为工程应用中是否需要在该等级机组上配备紧急补给水系统提供了参考和借鉴。最后还提出一种专门针对失电事故的安全阀设计设想。

关键词：超临界循环流化床机组失电水冷壁安全性安全阀

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艾里涡旋光束在大气湍流中的漂移特性研究

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中国激光 2015年第12期42卷 277-281页

作者：程振楚兴春赵尚弘邓博于张曦文空军工程大学陕西西安710000

采用多层相位屏法模拟了艾里涡旋光束在大气湍流中的漂移特性。讨论了拓扑电荷p、涡旋核相对于光束中心的离轴距离x_d,y_d和湍流强度C2n对艾里涡旋光束在不同传输距离处的漂移特性的影响。研究发现,在相同传输距离处,漂移量随着C2n的增... 详细信息

采用多层相位屏法模拟了艾里涡旋光束在大气湍流中的漂移特性。讨论了拓扑电荷p、涡旋核相对于光束中心的离轴距离x_d,y_d和湍流强度C2n对艾里涡旋光束在不同传输距离处的漂移特性的影响。研究发现,在相同传输距离处,漂移量随着C2n的增大而增大。在传输距离比较小时,p和x_d,y_d对漂移的影响比较弱,漂移量几乎相等。当传输距离比较大时,漂移量随p的增大而减小,随x_d,y_d的增大而增大。此外比较了单束艾里涡旋光束的漂移量和阵列艾里涡旋光束的漂移量,研究发现,阵列艾里涡旋光束的漂移量比较小。

关键词：大气光学艾里涡旋光束多层相位屏漂移

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