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On the Intelligent Optimization of the Crevice Structure in a Rapid Compression Machine

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Journal of Thermal Science 2024年第3期33卷 1200-1215页

作者： GUO Qiang LIU Jie WU Yingtao wang hewu TANG Chenglong YU Ruiguang Department of Power Mechanical Engineering Beijing Jiaotong UniversityBeijing100044China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing100084China Beijing Key Laboratory of New Energy Vehicle Powertrain Technology Beijing100044China National International Science and Technology Cooperation Base Beijing Jiaotong UniversityBeijing100044China

In this study,the multi-objective intelligent optimization of the crevice structure in a rapid compression machine(RCM)is carried out based on the RCM simulation model modified with the KIVA-3V program.A multi-objective optimization simulation model of the crevice structure based on the large eddy simulation model coupled with the genetic algorithm NSGA-Ⅲis *** optimization parameters and seven optimization objectives are selected in the optimization *** results show that the genetic algorithm can quickly find the values of the optimized *** crevice volume ratio shows a trade-off relationship with the dimensionless temperature ratio T_(max)/T_(aver)and the tumble ratio.A larger crevice volume can reduce the flow of boundary layer cryogenic gas into the combustion chamber,thus improving the temperature *** addition,the crevice entrance width and the connecting channel length should be smaller,while the volume of the crevice main chamber should be larger,so as to sufficiently introduce the low-temperature gas of the boundary layer into the crevice and reduce their influence on the temperature field of the combustion *** the crevice volume accounts for10%of the total volume,the temperature uniformity of the combustor is significantly enhanced,and when the crevice volume accounts for 30.4%,there is almost no low-temperature vortex in the combustion chamber.

关键词： rapid compression machine adiabatic core area ignition delay period crevice structure

Progress review of US-China joint research on advanced technologies for plug-in electric vehicles

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Science China(Technological Sciences) 2018年第10期61卷 1431-1445页

作者： OUYANG MingGao DU JiuYu PENG Huei wang hewu FENG XuNing SONG ZiYou State Key Laboratory of Automotive Safety and Energy Tsinghua University University of Michigan Mechanical Engineering

The United States and China are the world's largest automobile markets and oil consumers, and both face a severe challenge to conserve energy and reduce tailpipe emissions. Thus, both countries urgently need to transform conventional internal combustion engines to electrified powertrains. Targeting the advanced core technologies of plug-in electric vehicles(PEVs), a joint research collaboration between China and the US, called the "Clean Vehicle Consortium"(CVC), was set up in 2010. Six years of collaboration on PEV technologies has resulted in significant progress in three technical areas. Based on CVC publications,we review herein the progress made by the CVC research efforts on three key advanced PEV technologies. This includes the development of a safe battery with an energy density of 260 W h kg^(-1) and a systematic method for designing safe traction battery systems. Thus, a breakthrough in high power density and efficient traction motor systems has occurred. In addition to discussing advanced electric-drive powertrains, we also discuss global energy management strategies that aim to improve PEV energy efficiency. This discussion covers scientific and comprehensive analysis methods to analyze energy systems, which include costbenefit analyses of plug-in hybrid electric vehicles, life-cycle assessments for evaluating vehicle emissions, and PEV-ownership projections.

关键词： US-China joint research plug-in electric vehicle safety of traction battery electric driving powertrain energy system analysis

Constructing representative driving cycle for heavy duty vehicle based on Markov chain method considering road slope

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Energy and AI 2021年第4期6卷 88-96页

作者： Xinyi Jia hewu wang Liangfei Xu Qing wang Hang Li Zunyan Hu Jianqiu Li Minggao Ouyang State Key Lab of Automotive Safety and Energy School of Vehicle and MobilityTsinghua UniversityBeijing 100084China

Electrification of heavy duty vehicles(HDVs)is critical to realization of the target of carbon neutralization in the *** most HDVs,the influence of road slope on vehicle power usually cannot be ignored due to significant road slope variation during long driving *** order to design the powertrain system for electrified HDVs effectively,it is necessary to construct representative driving cycles with road slope *** are two difficulties for this task.(1)Road slope measuring devices are usually costly.A cheaper yet effective method for measuring road slope needs to be developed.(2)A 3D(three dimension)Markov chain method is usually utilized for constructing cycles with velocity and road *** method is complex and time consuming,and needs to be *** this paper,a 2D(two dimension)Markov chain method for addressing these issues is proposed.A road slope observation is designed based on normal GPS(Global Positioning System)signals and a high order Butterworth *** effectiveness of the method is *** velocity and road slope are collected and observed for the area between Beijing and Zhangjiakou in northern *** cycles with road slope are constructed using a 2D Markov chain method and a matching algorithm based on average *** the introduced technology,three representative driving cycles with road slope for urban,suburban and highway routes are *** results on vehicle power show that,the representative driving cycles are effective with relative errors less than 4%compared to the real driving *** driving cycles will be utilized in designing electric HDVs,such as hydrogen fuel cell vehicles in the future.

关键词： Driving cycles Markov chain method Power demand Road slope observation Segment matching

Thermal Runaway of Lithium-Ion Batteries Employing Flame-Retardant Fluorinated Electrolytes

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Energy & Environmental Materials 2023年第1期6卷 333-339页

作者： Junxian Hou Li wang Xuning Feng Junpei Terada Languang Lu Shigeaki Yamazaki Anyu Su Yoshiko Kuwajima Yongjiang Chen Tomoya Hidaka Xiangming He hewu wang Minggao Ouyang State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Daikin Industries Ltd.1-1Nishi-HitotsuyaSettsu Osaka 566-8585Japan Sichuan New Energy Vehicle Innovation Center Yibin 644002China

Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance;thus,they are considered as a promising solution for advanced lithium-ion batteries carrying both high-energy density and high ***,the fluorinated electrolytes are widely used to form stable electrolyte interphase,due to their chemical reactivity with lithiated graphite or ***,the influence of this reactivity on the thermal safety of batteries is seldom ***,we demonstrate that the flame-retardant fluorinated electrolytes help to reduce the flammability,while the lithium-ion batteries with flame-retardant fluorinated electrolytes still undergo thermal runaway and disclose their different thermal runaway pathway from that of battery with conventional *** reduction in fluorinated components(e.g.,LiPF 6 and fluoroethylene carbonate(FEC))by fully lithiated graphite accounts for a significant heat release during battery thermal *** 13%of total heat is sufficient to trigger the chain reactions during battery thermal *** study deepens the understanding of the thermal runaway mechanism of lithium-ion batteries employing flame-retardant fluorinated electrolytes,providing guidance on the concept of electrolyte design for safer lithium-ion batteries.

关键词： battery safety flame retardance fluorinated electrolytes lithium-ion battery thermal runaway

柴油机燃用二甲醚时采用排气再循环降低NO_x排放

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西安交通大学学报 2000年第7期34卷 9-11,51页

作者：王贺武周龙保蒋德明西安交通大学西安710049

在单缸直喷柴油机上燃用二甲醚和采用排气再循环时 ,进行了发动机性能和排放的试验研究 .结果表明 :与燃用柴油相比 ,发动机燃用二甲醚可以实现无烟燃烧 ,NOx 降低 30 % ,未燃碳氢和CO排放有所下降 ;随着排气再循环 (EGR)率的增加 ,未... 详细信息

在单缸直喷柴油机上燃用二甲醚和采用排气再循环时 ,进行了发动机性能和排放的试验研究 .结果表明 :与燃用柴油相比 ,发动机燃用二甲醚可以实现无烟燃烧 ,NOx 降低 30 % ,未燃碳氢和CO排放有所下降 ;随着排气再循环 (EGR)率的增加 ,未燃碳氢、CO和CO2 排放有所升高 ,发动机热效率仍然保持在较高的水平 ,NOx 排放得到大幅度降低 ;当进气中EGR率为 2 0 %左右时 ,NOx排放降低到无排气再循环的 6 0 % .

关键词：二甲醚排放柴油机排气再循环氮氧化物燃料

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关于电动汽车商业模式系统的理论思考

中国科技论坛 2012年第1期 44-48页

作者：叶强王贺武清华大学汽车安全与节能国家重点实验室北京100084

在经历了两年多的示范运行之后,电动汽车如何进一步开展商业化推广越来越成为行业和社会关注的焦点。可与此同时,在电动汽车商业模式的理论研究和实践创新方面还没有跟上。基于此,本文从系统论的角度提出了构建电动汽车商业模式系统理... 详细信息

在经历了两年多的示范运行之后,电动汽车如何进一步开展商业化推广越来越成为行业和社会关注的焦点。可与此同时,在电动汽车商业模式的理论研究和实践创新方面还没有跟上。基于此,本文从系统论的角度提出了构建电动汽车商业模式系统理论框架的思路,并结合示范运行的情况,分析了电动汽车商业模式的影响因素,最后以纯电动汽车为例描绘了中国电动汽车商业化推广的分阶段路线图。

关键词：电动汽车商业模式系统理论影响因素路线图

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车辆分矩式混合动力系统储能特性

农业工程学报 2013年第13期29卷 23-30页

作者：杜玖玉张洪辉王贺武清华大学汽车安全与节能国家重点实验室北京100084 清华大学中国车用能源中心北京100084 中国汽车技术研究中心北京100070

为了提高采用分矩式液压机械传动商用车的燃油经济性,论证该系统应用混合动力驱动的可行性,该文研究分矩式混合动力系统制动能量回收条件和特性,基于功率分流分析法,在Matlab中建立流量分析模型,分析了调速范围内的分流工况、循环工况... 详细信息

为了提高采用分矩式液压机械传动商用车的燃油经济性,论证该系统应用混合动力驱动的可行性,该文研究分矩式混合动力系统制动能量回收条件和特性,基于功率分流分析法,在Matlab中建立流量分析模型,分析了调速范围内的分流工况、循环工况下的驱动功率流和制动功率流特性,并建立了制动能量回馈过程的转速、流量和转矩约束条件方程,得出了不同工况的制动能量回收特性。获得了不同工况条件下,可满足制动能量回收条件的液压元件相对变量率控制区间。为了验证理论分析结论,搭建了试验台,对分流工况和循环工况制动能量回收特性进行了试验台架验证。研究结果表明:分矩汇速式液压机械传动系统循环工况制动能量回收能力有限,分流工况高效制动能量回收效率较高,应用多段式方案制动能量回收潜力高约60%。研究结果可为制定合理的控制策略和评估系统的综合节油潜力提供参考。

关键词：车辆功率控制能量存储制动能量回收

基于出行里程分布的PHEV平均燃油消耗计算方法

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汽车工程 2014年第12期36卷 1421-1427页

作者：侯聪王贺武欧阳明高清华大学汽车安全与节能国家重点实验室北京100084 重庆长安汽车股份有限公司重庆400023

本文中提出了一种根据车队出行里程分布来计算插电式混合动力汽车(PHEV)车队的平均油耗的方法,并利用北京市区乘用车出行里程分布,计算了丰田Prius Plug-in、通用Volt和菲斯科Karma在北京地区使用的平均油耗。结果表明,3种车型在北京市... 详细信息

本文中提出了一种根据车队出行里程分布来计算插电式混合动力汽车(PHEV)车队的平均油耗的方法,并利用北京市区乘用车出行里程分布,计算了丰田Prius Plug-in、通用Volt和菲斯科Karma在北京地区使用的平均油耗。结果表明,3种车型在北京市区的平均100km油耗分别为3.37、1.83和3.91L;其中Prius Plug-in和Volt的平均油耗比传统车丰田Corolla分别降低58.47%和77.45%;该方法可用于计算PHEV车队的平均油耗和单个PHEV在某段较长时间内使用的平均油耗。

关键词：插电式混合动力汽车出行里程分布燃油消耗率利用系数

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中美PHEV能耗评价方法对比研究

汽车工程 2015年第1期37卷 1-8页

作者：侯聪王贺武欧阳明高清华大学汽车安全与节能国家重点实验室北京100084 重庆长安汽车股份有限公司重庆400023

研究了中国和美国对于插电式混合动力乘用车(PHEV)油耗与电耗的评价方法。通过从测试标准与指标计算两方面进行对比,指出了我国现行PHEV能耗评价方法中的不足,包括PHEV能耗标签的缺失、不能获得混合式PHEV的续驶里程和未考虑出行特征对P... 详细信息

研究了中国和美国对于插电式混合动力乘用车(PHEV)油耗与电耗的评价方法。通过从测试标准与指标计算两方面进行对比,指出了我国现行PHEV能耗评价方法中的不足,包括PHEV能耗标签的缺失、不能获得混合式PHEV的续驶里程和未考虑出行特征对PHEV能耗的影响等。最后提出了加强出行特征研究以完善我国PHEV能耗评价方法的建议。

关键词： PHEV 油耗电耗评价