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Analysis of the Influence of Geometrical Parameters on the Performance of a Proton Exchange Membrane Fuel Cell

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Fluid Dynamics & Materials Processing 2024年第1期20卷 219-237页

作者： Guodong Zhang Huifang Tao Da li Kewei Chen Guoxiang li shuzhan Bai Ke Sun School of Energy and Power Engineering Shandong UniversityJinan250061China Sinotruk Jinan Special Purpose Vehicle Co. Ltd.Jinan250117China

A suitable channel structure can lead to efficient gas distribution and significantly improve the power density of fuel cells.In this study,the influence of two channel design parameters is investigated,namely,the ratio of the channel width to the bipolar plate ridge width(i.e.,the channel ridge ratio)and the channel depth.The impact of these parameters is evaluated with respect to the flow pattern,the gas composition distribution,the temperature field and the fuel cell output capability.The results show that a decrease in the channel ridge ratio and an increase in the channel depth can effectively make the distributions of velocity,temperature and concentration more uniform in each channel and improve the output capability of the fuel cell.An increase in the channel ridge ratio and depth obviously reduces the flow resistance and improves the flow characteristics.

关键词： Hydrogen fuel cell bipolar plate flow channel multiphysics coupling

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水下井口吸力桩极限贯入深度研究

中国海上油气 2024年第2期36卷 185-194页

作者：李舒展杨进朱国倞黄熠张珣万宏宇中国石油大学(北京)安全与海洋工程学院北京102249 中国海油南海油气能源院士工作站海南海口570312 中海石油(中国)有限公司湛江分公司广东湛江524000

井口吸力桩表层建井技术在天然气水合物开采、边际油田开发、军事航道区水下开发等领域具有良好应用前景,但在井口吸力桩安装过程中存在贯入不到位导致水下井口出泥过高引发钻井工况复杂载荷下水下井口失稳难题,有必要开展极限贯入深度... 详细信息

井口吸力桩表层建井技术在天然气水合物开采、边际油田开发、军事航道区水下开发等领域具有良好应用前景,但在井口吸力桩安装过程中存在贯入不到位导致水下井口出泥过高引发钻井工况复杂载荷下水下井口失稳难题,有必要开展极限贯入深度研究。基于井口吸力桩贯入阶段力学模型,考虑沉贯阻力和极限吸力,建立了井口吸力桩极限贯入深度模型。结合南海西部X井位工程实例,开展了井口吸力桩表层建井设计,计算了直径为6 m的井口吸力桩贯入过程中的阻力,给出了井口吸力桩极限吸力设计参数。计算结果表明:在南海西部X井位安装井口吸力桩,其极限吸力的主要限制因素为临界吸力和水泵吸力;极限贯入深度主要受土质类型和强度、临界吸力的影响,强度高和渗透性好的土体会导致极限贯入深度减小;X井位井口吸力桩极限贯入深度为26.75 m。本文极限贯入深度的计算分析可为井口吸力桩的设计和现场施工提供技术参考。

关键词：水下井口吸力桩贯入深度极限吸力

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Digital Karyotyping with Whole Genomic Sequencing for Complex Congenital Disorder

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Journal of Genetics and Genomics 2015年第11期42卷 651-655页

作者： Rongrong Chen shuzhan li Gongshu liu Yuan Yuan Jiucheng liu Tao liu Renhua Wu Qian Sun Xiubao Ren Xin Yi Hongbing Zhang Department of Immunology Key Laboratory of Cancer Immunology and BiotherapyNational Clinical Research Center of CancerTianjin Medical University Cancer Institute and Hospital BGI-Tianjin State Key Laboratory of Medical Molecular Biology Department of PhysiologyInstitute of Basic Medical SciencesChinese Academy of Medical Sciences and Peking Union Medical College Tianjin Women and Children Health Center

Complex congenital disorders may be caused by multiple genetic alterations and/or environmental hazards. Diagnosis and management of these diseases are usually difficult. Robust next-generation sequencing （NGS） technologies provide unprecedented opportunities to maximize mutation detection and improve genetic counseling and clinical management. Targeted or whole exome sequencing （WES） mainly detects protein-coding DNA sequence aberrations and is the major DNA sequencing technology that is entering clinical practice （liu et al., 2014）.

关键词： WGS Digital Karyotyping with Whole Genomic Sequencing for Complex Congenital Disorder gene CGH

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Influence of Urea Uneven Injection on the Performances of a Diesel Engine

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Fluid Dynamics & Materials Processing 2023年第1期19卷 83-93页

作者： Chang Huang shuzhan Bai Guoxiang li Ke Sun School of Energy and Power Engineering Shandong UniversityJinan250061China

The influence of heterogeneous flow injection of urea at different velocities and temperatures on NO x conversion efficiency,ammonia storage and ammonia leakage is investigated experimentally.A diesel engine employing a selective catalytic reduction(SCR)technology is considered.It is found that for a fixed injection velocity,the degree of ammonia leakage changes depending on the temperature.The higher the temperature,the faster the catalytic reduction reaction and the smaller the degree of ammonia leakage.The temperature has a great influence on the catalytic reduction reaction rate.At an injection velocity of 10000/h,the average reaction rate at 420℃ is 12 times higher than that at 180℃.The injection velocity has a weak influence on the reaction rate.When the injection velocity changes from 10000/h to 40000/h at the same temperature,the average reaction rate does not change appreciably.However,increasing the space velocity can accelerate the leakage of ammonia,thereby miti-gating the benefits associated with the NO_(x) conversion.

关键词： Diesel engine ammonia leak conversion efficiency the urea flow

CFD-Based Optimization of a Diesel Engine Waste Heat Recycle System

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Fluid Dynamics & Materials Processing 2023年第6期19卷 1479-1493页

作者： Da li Guodong Zhang Ke Sun shuzhan Bai Guoxiang li School of Energy and Power Engineering Shandong UniversityJinan250061China

A dedicated heat exchanger model is introduced for the optimization of heavy-duty diesel engines.The model is a prerequisite for the execution of CFD simulations,which are used to improve waste heat recovery in these systems.Several optimization methods coupled with different types of working fluids are compared in terms of exergy efficiency and heat exchanger complicity.The three considered optimization methods all lead to significant improvements in the R245fa and R1233zd systems with a comparatively low evaporation temperature.The optimal R245fa system has the highest efficiency increase(77.49%).The cyclopentane system displays the highest efficiency among the optimized ORC(Organic Rankine Cycle)systems,yet achieved by using a much heavier evaporator HEC(Heat Exchanging Core).In contrast,the 96.84%efficiency increase for the optimized R1233zd is achieved with only 68.96%evaporator weight.

关键词： Tube-fin heat exchanger heat exchanging core organic rankine cycle working fluid

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水下卧式采油树在役工况安全风险分析

石油机械 2024年第5期52卷 63-70页

作者：任冠龙王宇孟文波张崇李舒展中海石油(中国)有限公司湛江分公司中海油研究总院有限责任公司中国石油大学(北京)

深水油气生产对水下采油树系统的可靠性有着极高的要求。为保障我国首套国产化深水水下采油树在役生产工况下的安全运行,建立了改进型危险与可操作性分析法(HAZOP),将改进后的发生可能性和严重度等级划分及风险矩阵作为风险评判的依据,... 详细信息

深水油气生产对水下采油树系统的可靠性有着极高的要求。为保障我国首套国产化深水水下采油树在役生产工况下的安全运行,建立了改进型危险与可操作性分析法(HAZOP),将改进后的发生可能性和严重度等级划分及风险矩阵作为风险评判的依据,通过对油气生产过程、化学药剂注入过程以及水下控制系统电力/通信过程等3个生产节点进行风险评价,得到水下采油树在役过程中的36个中度风险点,并提出了相应措施;采用数值模拟方法,建立了水下采油树-井口系统力学模型,对系统在役过程中所受到的海流载荷、地震与腐蚀等风险进行分析。研究结果表明,水下采油树在各类工况下的最大应力在20 MPa以下,最大弯矩在0.3 MN·m以下,安全性满足生产要求;但在腐蚀后百年一遇海流及大于6.5级地震载荷下,系统最大弯矩超出极端环境许用值,安全性不能保障。所得结论可为我国水下采油树的应用提供指导,能够有效保障采油树服役期间的安全性。

关键词：水下采油树井口系统在役工况 HZAOP 外部载荷风险分析

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血细胞相关炎症指标与糖尿病视网膜病变的关系:北辰眼病研究

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中华眼底病杂志 2024年第2期40卷 109-115页

作者：徐舒展高飞陈丽梅苗小霞李筱荣刘巨平天津医科大学眼科医院、眼视光学院、眼科研究所国家眼耳鼻喉疾病临床医学研究中心天津市分中心天津市视网膜功能与疾病重点实验室天津300384

目的观察血细胞相关炎症指标与糖尿病视网膜病变(DR)的相关性。方法横断面研究。2020年6月至2022年2月天津医科大学眼科医院进行的北辰眼病研究Ⅰ期数据纳入研究。研究内容包括:问卷调查、常规全身和眼部检查及实验室血细胞相关指标血... 详细信息

目的观察血细胞相关炎症指标与糖尿病视网膜病变(DR)的相关性。方法横断面研究。2020年6月至2022年2月天津医科大学眼科医院进行的北辰眼病研究Ⅰ期数据纳入研究。研究内容包括:问卷调查、常规全身和眼部检查及实验室血细胞相关指标血小板平均体积(MPV)、血小板分布宽度(PDW)、中性粒细胞、淋巴细胞检查,计算中性粒细胞/淋巴细胞比值(NLR)和血小板/淋巴细胞比值(PLR)。DR诊断及分型参照DR国际临床分级标准进行。单眼或双眼DR均定义为DR患者。根据是否患有糖尿病及DR,将受检者分为非糖尿病组、糖尿病无DR组、DR组。定量资料多组间比较采用Kruskal-Wallis H检验;两组间比较采用Wilcoxon秩和检验。组间分类变量比较采用χ^(2)检验。逐步调整变量,构建未经调整的单变量模型以及调整不同参数后的模型Ⅰ、Ⅱ、Ⅲ。不同模型下MPV、PDW、NLR、PLR与DR的相关性行logistic回归分析。受试者工作特征(ROC)曲线分析NLR不同模型对DR的诊断效能。结果共招募受检者3328名。其中,男性1121名(33.68%,1121/3328),女性2207名(66.32%,2207/3328);年龄61.84(6.05)岁。非糖尿病组、糖尿病无DR组、DR组分别为2679、476、173名。三组受检者MPV、PLR比较,差异无统计学意义(H=5.98、1.94,P=0.051、0.379);但与非糖尿病组、糖尿病无DR组比较,DR组PDW、NLR呈上升趋势。完全调整相关因素的模型Ⅲ中,非糖尿病组与DR组[比值比(OR)=1.440,95%可信区间(CI)1.087~1.920,P=0.041]、糖尿病无DR组与DR组(OR=1.990,95%CI 1.440~2.749,P<0.001),NLR均是DR发生的独立危险因素。ROC曲线分析结果显示,NLR的模型Ⅲ诊断效能最高,曲线下面积为0.751(95%CI 0.706~0.796,P<0.001),最佳截断值为0.390,灵敏度、特异性分别为74.3%、64.8%。结论与非糖尿病、糖尿病无DR受检者比较,DR组患者NLR显著增高;NLR是DR发生的独立危险因素。

关键词：糖尿病视网膜病变血小板/淋巴细胞比值中性粒细胞/淋巴细胞比值血小板平均体积血小板分布宽度危险因素

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燃料电池极板过渡区结构的优化设计

内燃机与动力装置 2024年第2期41卷 11-18,27页

作者：赵明李国祥王桂华白书战山东大学能源与动力工程学院山东济南250061

为解决质子交换膜燃料电池(proton exchange membrane fuel cells,PEMFC)反应区流道燃料分配不均匀性,采用计算流体力学方法对流道燃料流动进行仿真,采用变异系数对不同方案进行评价,研究过渡区中圆柱体积占比、圆柱排列方式、圆柱到流... 详细信息

为解决质子交换膜燃料电池(proton exchange membrane fuel cells,PEMFC)反应区流道燃料分配不均匀性,采用计算流体力学方法对流道燃料流动进行仿真,采用变异系数对不同方案进行评价,研究过渡区中圆柱体积占比、圆柱排列方式、圆柱到流道距离、过渡区圆柱开孔率对燃料分配均匀性的影响。结果表明:采用圆柱导流的燃料分配均匀性优于导流道导流;过渡区圆柱采用正方形排列时燃料分配均匀性最佳;增加圆柱到流道的距离,各流道燃料分配均匀性呈现先升高后下降的趋势,距离为3 mm时均匀性较好;过渡区开孔率约为11.4%时燃料分配均匀性较好,过大过小都会造成分配均匀性恶化。

关键词： PEMFC 极板数值模拟流场设计性能优化

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A Novel Method for the Application of the ECMS(Equivalent Consumption Minimization Strategy)to Reduce Hydrogen Consumption in Fuel Cell Hybrid Electric Vehicles

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Fluid Dynamics & Materials Processing 2022年第4期18卷 867-882页

作者： Wen Sun Hao liu Ming Han Ke Sun shuzhan Bai Guoxiang li School of Energy and Power Engineering Shandong UniversityJinan250061China

Fuel cell hybrid electric vehicles are currently being considered as ideal means to solve the energy crisis and global warming in today’s society.In this context,this paper proposes a method to solve the problem related to the dependence of the so-called optimal equivalent factor(determined in the framework of the equivalent consumption minimum strategy-ECMS)on the working conditions.The simulation results show that under typical conditions(some representative cities being considered),the proposed strategy can maintain the power balance;for different initial battery’s states of charge(SOC),after the SOC stabilizes,the fuel consumption is 5.25 L/100 km.

关键词： Energy management fuel cell hybrid electric vehicle dynamic programming adaptive equivalent consumption minimum strategy