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高温多组分混合气体热导率理论预测

工程热物理学报 2024年第8期45卷 2460-2465页

作者：缐磊曹涛锋陈磊陶文铨西安交通大学能源与动力工程学院热流科学与工程教育部重点实验室西安710049 西安航天动力技术研究所固体推进全国重点实验室西安710100

准确获取高温燃气的热学性质是开展火箭发动机喷管数值仿真的基础。由于采用实验方法获取高温下气体热导率极其困难,基于理论计算手段预测高温下气体热导率成为更好的选择。本研究中,使用考虑高温电子激发态的Istomin修正计算了H_(2)、C... 详细信息

准确获取高温燃气的热学性质是开展火箭发动机喷管数值仿真的基础。由于采用实验方法获取高温下气体热导率极其困难,基于理论计算手段预测高温下气体热导率成为更好的选择。本研究中,使用考虑高温电子激发态的Istomin修正计算了H_(2)、CO以及N_(2)气体在300~4000 K温度范围内的热导率。结合Wassiljewa方程构建了高温下多组分混合气体导热性质理论预测模型,预测了两种燃烧气体在300~4000 K温度范围的混合气体热导率,为喷管精细化仿真提供燃气热学性质参考数据。

关键词：燃烧气体高温热导率火箭发动机

Ca(OH)_(2)脱水过程数值研究及强化

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工程热物理学报 2024年第1期45卷 143-151页

作者：张严心王梦祎陈黎周宇昊陶文铨西安交通大学热流科学与工程教育部重点实验室西安710049 华电电力科学研究院有限公司杭州310030

建立了Ca(OH)_(2)/CaO反应器脱水过程的多孔介质流动换热模型,对Ca(OH)_(2)/CaO热化学储能系统的脱水过程进行了三维数值模拟研究,分析了储能系统在脱水过程中温度、反应物浓度的动态变化,并针对该反应系统设计了一系列强化传热传质措施... 详细信息

建立了Ca(OH)_(2)/CaO反应器脱水过程的多孔介质流动换热模型,对Ca(OH)_(2)/CaO热化学储能系统的脱水过程进行了三维数值模拟研究,分析了储能系统在脱水过程中温度、反应物浓度的动态变化,并针对该反应系统设计了一系列强化传热传质措施,通过增加多种类型翅片、添加多孔通道及金属板、改变反应器高径比、采用圆台型反应器来强化传热及传质,分析了各种工况下储能系统的温度、压力变化情况。结果表明:添加翅片有利于强化反应器的传热性能,提高脱水过程速率;添加多孔通道一方面可以强化传热,另一方面多孔结构可以作为水蒸气的扩散通道,减小水蒸气扩散阻力,强化传质;在孔隙率不变的前提下,增大反应器高径比会强化反应器的传热性能,但是会增加水蒸气扩散阻力。改变反应器高径比会对反应器传热及传质性能产生影响;采用圆台型反应器时,其脱水反应的快慢取决于反应器最大截面处的反应速率大小。相比于传质,传热对圆台反应器的脱水过程起主要影响;对于研究尺寸下的反应器,强化传热对反应系统性能的提升作用优于强化传质。研究结果可为热化学储能反应器的结构优化与性能提升提供一定的参考价值。

关键词：热化学储能 Ca(OH)_(2)/CaO 多孔介质翅片多孔通道

宽雷诺数下肋参数对U型内冷通道流动与换热特性影响的实验研究

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西安交通大学学报 2024年第6期58卷 103-113页

作者：万红牛丁俣中程想陈黎王进冀文涛陶文铨西安交通大学热流科学与工程教育部重点实验室西安710049 河北工业大学能源与环境工程学院天津300401

为了研究肋高和通道高的比值(e/H)、肋间距与肋高的比值(P/e)以及肋角度(α)对U型带肋通道流动与换热特性的影响,采用铜板法结合热电偶测量壁面温度分布,对6个不同肋参数U型带肋通道的表面换热特性进行了实验研究。带肋通道截面为正方形... 详细信息

为了研究肋高和通道高的比值(e/H)、肋间距与肋高的比值(P/e)以及肋角度(α)对U型带肋通道流动与换热特性的影响,采用铜板法结合热电偶测量壁面温度分布,对6个不同肋参数U型带肋通道的表面换热特性进行了实验研究。带肋通道截面为正方形,实验的Re为5.0×10^(3)~1.0×10^(5)。研究结果表明,随着e/H和Re的增大,带肋通道的对流换热系数逐渐增大,但相应的流动损失增幅明显,e/H从0.08增大到0.12时,通道的阻力系数增大了近一倍。对于e/H=0.08的通道,P/e分别为6、8、10时,P/e为8时的对流换热系数和阻力损失均高于其他两种情况。相较于90°正交肋,带角度的斜肋能够进一步增强带肋通道的对流换热,75°肋的强化效果略强于60°肋。在实验参数范围内,对于几种不同的带肋U型通道,对流换热系数为光滑通道的1.9~3.0倍,阻力系数为光滑通道的4~16倍。综合考虑换热与流阻,e/H=0.08、P/e=8、α=45°的通道性能最好。

关键词：涡轮叶片内部冷却带肋通道对流换热

Numerical Investigation on Dropwise Condensation on Rough Structures with and without Non-Condensable Gas

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Journal of Thermal Science 2022年第2期31卷 308-317页

作者： LI Mingjie ZHOU Wenjing WEI Jinjia tao wenquan School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an710049China Key Laboratory of Thermo-Fluid Science and Engineering Ministry of EducationSchool of Energy&Power EngineeringXi’an Jiaotong UniversityXi’an710049China

The geometrical dimensions of the rough structures as well as the non-condensable gases in the vapor mixture can have the great effect on the nucleation position and the wetting state of the droplet,which further influence the condensation heat *** this paper,the multispecies multiphase lattice Boltzmann method together with a thermal phase change model is used to investigate the dropwise condensation on a rough surface enhanced with *** effect of the geometric dimensions including pillar height H,pillar width W and pillar space S is *** the effect of non-condensable gases on the contact angle of a droplet on textured surface is *** results show that the local heat flux and the wetting area are higher while the waiting time is shorter at larger S,W and smaller H on the rough *** nucleation position rises from the bottom of grooves to the top with the increase of pillar height and the decrease of pillar *** contact angle is larger and it is easier to maintain the Cassie state for *** there exists non-condensable gas,the non-condensable gas obviously enhances the hydrophobicity of the rough surfaces compared with pure vapor.

关键词： 1condensation wetting state lattice Boltzmann method numerical simulation

Direct methanol fuel cells system-A review of dual-role electrocatalysts for oxygen reduction and methanol oxidation

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Journal of Materials Science & Technology 2022年第19期114卷 29-41页

作者： Yuanhui Zuo Wenchao Sheng wenquan tao Zhuo Li College of Environment Science and Engineering Tongji UniversityShanghai 200092China

One fundamental challenge in exploiting direct methanol fuel cells(DMFCs)is the preparation of inex-pensive,high active electrocatalysts,which are highly active and durable for the two half-reactions,i.e.,the methanol oxidation reaction(MOR)at the anode and the oxygen reduction reaction(ORR)at the *** group metals-based catalysts have been known the governing dual-functional electro-catalysts based on the literature *** these catalysts are expensive and commercialize the DMFC less *** addition to the high-cost,there are also methanol crossover,CO poisoning,long-term instability,and other problems as for Pt-based *** the dual-role MOR&ORR catalysts,methanol crossover is inevitable to a certain extent on the current development of DMFC with losses in terms of cell *** this regard,one strategy is to exploit high selective anodic/cathodic electrocatalysts to cap-italize the energy density at a high concentration of *** to the summary results,there are mainly two types of dual-role electrocatalysts:one is Pt-support/co-catalyst(designated as P-S/C)for MOR/ORR,the other is catalyst/co-catalyst(designated as C/C)for MOR/*** paper aims to review the design and construction of the various dual-role catalysts and give some discussion briefly.

关键词： DMFC Dual-role Pt-support/co-catalyst Catalyst/co-catalyst MOR/ORR

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面向金属泡沫散热器设计的自然对流拓扑优化

西安交通大学学报 2024年第10期58卷 72-82页

作者：罗纪旺陈黎郑鑫建杨骐瑞陶文铨西安交通大学热流科学与工程教育部重点实验室西安710049

针对传统方块型金属泡沫散热器散热效率不高,难以满足高功率电子器件散热需求的问题,发展了基于格子Boltzmann和水平集方法的三维拓扑优化方法。首先,采用格子Boltzmann方法求解多孔介质内的流动和传热过程;然后,采用伴随格子Boltzmann... 详细信息

针对传统方块型金属泡沫散热器散热效率不高,难以满足高功率电子器件散热需求的问题,发展了基于格子Boltzmann和水平集方法的三维拓扑优化方法。首先,采用格子Boltzmann方法求解多孔介质内的流动和传热过程;然后,采用伴随格子Boltzmann方法计算梯度;最后,根据反应-扩散方程更新水平集函数。通过对底部放置发热元件方腔的自然对流过程开展拓扑优化,得到特征格拉晓夫数为2.4×10^(2)~1.2×10^(5)的4种优化散热器结构,定量评估了散热器的强化换热性能并分析相关机理。研究结果表明:随着格拉晓夫数的增大,散热主导机制由热传导转变为热对流,优化结构由伸展的树枝状向收缩的花朵状结构转变,以留出更多空间使得流动涡旋充分发展;与传统的金属泡沫方块结构和开槽的金属泡沫块结构相比,所提优化结构表现出优异的散热性能,其分支结构和中空结构能够优化方腔内的流动,从而将散热效率提升了29.7%以上,表明了所提拓扑优化方法的有效性。研究工作可为新型金属泡沫散热器的设计提供理论指导。

关键词：散热器设计强化换热伴随格子Boltzmann方法金属泡沫拓扑优化

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Extension of the pressure correction method to zero-Mach number compressible flows

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Science China(Technological Sciences) 2009年第6期52卷 1583-1595页

作者： HE YaLing HUANG Jing tao YuBing tao wenquan State Key Laboratory of Multiphase Flow in Power Engineering School of Energy&Power EngineeringXi’an Jiaotong UniversityXi’an 710049China

In the present paper,the classical pressure correction method was extended into low Mach number compressible flow regime by integrating equation of state into SIMPLE *** self-developed code based on this algorithm was applied to predicting the lid-driven cavity flow and shock tube prob-lems,and the results showed good agreement with benchmark solutions and the Mach number can reach the magnitude of as low as *** attenuation of sound waves in viscous medium was then *** results agree well with the analytical solutions given by theoretical *** demonstrated that the present method could also be implemented in acoustics field simulation,which is crucial for thermoacoustic simulation.

关键词： thermoacoustic engine pressure correction method low Mach number compressible flow

A Multi-Scale Thermal Analysis Method for Data Centers with Application in a Ship Data Center

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Journal of Thermal Science 2021年第6期30卷 1973-1985页

作者： DAI Yanjun ZHAO Jie SHI Jiwei WANG Wei tao wenquan Key Laboratory of Thermo-Fluid Science and Engineering of MOE School of Energy and Power EngineeringXi'an Jiaotong UniversityXi’an 710049China Science and Technology on Thermal Energy and Power Laboratory Wuhan 430205China Key Laboratory of Data Center Energy Saving&Low Carbon Techniques of Xi’an Xi’an 710049China

Thermal analysis of data centers is in urgent need to ensure that computer chips remain below the critical temperature while the energy consumption for cooling can be *** is difficult to obtain detailed hotspot locations and temperatures of chips in large data centers containing hundreds of racks or more by direct *** this paper,a multi-scale thermal analysis method is proposed that can predict the temperature distribution of chips and solder balls in data *** multi-scale model is divided into six scales:room,rack,server,Insulated-Gate Bipolar Transistor(IGBT),chip and solder ball.A concept of sub-model is proposed and the six levels are organized into four simulation ***-model 1 contains Room,Rack and Server(RRS);Sub-model 2 contains Server and IGBT(SI);Sub-model 3 contains IGBT and Chip(IC),and Sub-model 4 contains Chip and Solder-ball(CS).These four sub-models are one-way coupled by transmitting their results as boundary conditions between *** full-field simulation method is employed to verify the efficiency and accuracy of multi-scale simulation method for a single-rack data *** two simulation results show that the highest temperature emerges in the same *** Single-rack Full-field Model(SRFFM)costs 2.5 times more computational time than that with Single-rack Multi-scale Model(SRMSM).The deviation of the highest temperature of chips and solder balls are 1.57℃and 0.2℃between the two models which indicates that the multi-scale simulation method has good prospect in the data center thermal ***,the multi-scale thermal analysis method is applied to a ship data center with 15 racks.

关键词： thermal analysis computational fluid dynamics multi-scale simulation full-field simulation data center

Liquid-based high-temperature receiver technologies for next-generation concentrating solar power:A review of challenges and potential solutions

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能源前沿:英文版 2023年第1期17卷 16-42页

作者： Ya-Ling HE Wenqi WANG Rui JIANG Mingjia LI wenquan tao Key Laboratory of Thermo-Fluid Science and Engineering of the Ministry of Education School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China

To reduce the levelized cost of energy for concentrating solar power(CSP),the outlet temperature of the solar receiver needs to be higher than 700°C in the next-generation *** of extensive engineering application experience,the liquid-based receiver is an attractive receiver technology for the next-generation *** review is focused on four of the most promising liquid-based receivers,including chloride salts,sodium,lead-bismuth,and tin *** challenges of these receivers and corresponding solutions are comprehensively reviewed and *** is concluded that combining salt purification and anti-corrosion receiver materials is promising to tackle the corrosion problems of chloride salts at high *** addition,reducing energy losses of the receiver from sources and during propagation is the most effective way to improve the receiver ***,resolving the sodium fire risk and material compatibility issues could promote the potential application of liquid-metal ***,using multiple heat transfer fluids in one system is also a promising way for the next-generation *** example,the liquid sodium is used as the heat transfer fluid while the molten chloride salt is used as the storage *** the end,suggestions for future studies are proposed to bridge the research gaps for>700℃liquid-based receivers.

关键词： next-generation concentrating solar power liquid-based solar receiver molten salt liquid metals