Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 214

年份

2024 1

2023 15

2022 17

2021 14

2020 15

2019 16

2018 12

2017 12

2016 6

2015 8

2014 9

2013 20

2012 4

2011 11

2010 12

2009 8

2008 10

2007 4

2005 4

2004 2

展开︾

关键词

固体氧化物燃料电池 8

燃料电池 8

新能源 3

氢能 3

生物质 3

SOFC 2

催化剂 2

压水堆 2

双极板 2

替代燃料 2

柴油 2

核燃料循环 2

氢燃料电池 2

汽油 2

清洁燃料 2

燃烧特性 2

碳基燃料 2

2035 1

300 M钢 1

展开︾

检索范围：

排序：展示方式：

Analysis of molten metal spreading and solidification behaviors utilizing moving particle full-implicit method

《能源前沿（英文）》 2021年第15卷第4期页码 959-973 doi: 10.1007/s11708-021-0753-0

摘要： To retrieve the fuel debris in Fukushima Daiichi Nuclear Power Plants (1F), it is essential to infer the fuel debris distribution. In particular, the molten metal spreading behavior is one of the vital phenomena in nuclear severe accidents because it determines the initial condition for further accident scenarios such as molten core concrete interaction (MCCI). In this study, the fundamental molten metal spreading experiments were performed with different outlet diameters and sample amounts to investigate the effect of the outlet for spreading-solidification behavior. In the numerical analysis, the moving particle full-implicit method (MPFI), which is one of the particle methods, was applied to simulate the spreading experiments. In the MPFI framework, the melting-solidification model including heat transfer, radiation heat loss, phase change, and solid fraction-dependent viscosity was developed and implemented. In addition, the difference in the spreading and solidification behavior due to the outlet diameters was reproduced in the calculation. The simulation results reveal the detailed solidification procedure during the molten metal spreading. It is found that the viscosity change and the solid fraction change during the spreading are key factors for the free surface condition and solidified materials. Overall, it is suggested that the MPFI method has the potential to simulate the actual nuclear melt-down phenomena in the future.

关键词： molten metal spreading solidification particle method severe accident fuel debris decommissioning

HTML PDF 收藏

GIS-based numerical simulation of Amamioshima debris flow in Japan

Jian WU, Guangqi CHEN, Lu ZHENG, Yingbin ZHANG

《结构与土木工程前沿（英文）》 2013年第7卷第2期页码 206-214 doi: 10.1007/s11709-013-0198-6

摘要： Debris flow is a rapid flow which could lead to severe flooding with catastrophic consequences such as damage to properties and loss of human lives. It is important to study the movement of debris flow. Since during a debris flow process, the erosion and deposition processes are important, the no entrainment assumption is not acceptable. In this study, first we considered the debris flow as equivalent fluid and adopted the depth-averaged govern equations to simulate the movements and evolution of river bed. Secondly, the set of partial differential equations was solved numerically by means of explicit staggered leap-frog scheme that is accurate in space and time. The grid of difference scheme was derived from GIS raster data. Then the simulation results can be displayed by GIS and easily used to form the hazard maps. Finally, the numerical model coupled with GIS is applied to simulate the debris flow occurred on Oct. 20th, 2010, in Amamioshima City, Japan. The simulation reproduces the movement, erosion and deposition. The results are shown to be consistent with the field investigation.

关键词： debris flow numerical simulation GIS movement erosion deposition

HTML PDF 收藏

Windborne debris damage prediction analysis

Fangfang SONG, Jinping OU,

《结构与土木工程前沿（英文）》 2010年第4卷第3期页码 326-330 doi: 10.1007/s11709-010-0067-5

摘要： Windborne debris is one of the most important causes of the envelop destruction according to the post-damage investigations. The problem of windborne debris damage could be summarized as three parts, including windborne debris risk analysis, debris flying trajectories, and impact resistance of envelope analysis. The method of debris distribution is developed. The flying trajectories of compact and plate-like debris are solved by using a numerical method according to the different aerodynamic characteristics. The impact resistance of the envelopes is also analyzed. Besides, the process of windborne debris damage analysis is described in detail. An example of industrial building is given to demonstrate the whole method by using the observed data of typhoon Chanchu (2006). The method developed in this paper could be applied to risk assessment of windborne debris for structures in wind hazard.

关键词： typhoon windborne debris structural envelopes damage estimation

HTML PDF 收藏

Combustion and emissions of RP-3 jet fuel and diesel fuel in a single-cylinder diesel engine

《能源前沿（英文）》 2023年第17卷第5期页码 664-677 doi: 10.1007/s11708-021-0787-3

摘要： The combustion characteristics and emission behaviors of RP-3 jet fuel were studied and compared to commercial diesel fuel in a single-cylinder compression ignition (CI) engine. Engine operational parameters, including engine load (0.6, 0.7, and 0.8 MPa indicating the mean effective pressure (IMEP)), the exhaust gas recirculation (EGR) rate (0%, 10%, 20%, and 30%), and the fuel injection timing (−20, −15, −10, and −5 ° crank angle (CA) after top dead center (ATDC)) were adjusted to evaluate the engine performances of RP-3 jet fuel under changed operation conditions. In comparison to diesel fuel, RP-3 jet fuel shows a retarded heat release and lagged combustion phase, which is more obvious under heavy EGR rate conditions. In addition, the higher premixed combustion fraction of RP-3 jet fuel leads to a higher first-stage heat release peak than diesel fuel under all testing conditions. As a result, RP-3 jet fuel features a longer ignition delay (ID) time, a shorter combustion duration (CD), and an earlier CA50 than diesel fuel. The experimental results manifest that RP-3 jet fuel has a slightly lower indicated thermal efficiency (ITE) compared to diesel fuel, but the ITE difference becomes less noticeable under large EGR rate conditions. Compared with diesel fuel, the nitrogen oxides (NO_x) emissions of RP-3 jet fuel are higher while its soot emissions are lower. The NO_x emissions of RP-3 can be effectively reduced with the increased EGR rate and delayed injection timing.

关键词： RP-3 jet fuel diesel engine combustion emissions

HTML PDF 收藏

Impacts of methanol fuel on vehicular emissions: A review

《环境科学与工程前沿（英文）》 2022年第16卷第9期 doi: 10.1007/s11783-022-1553-4

摘要：

● Methanol effectively reduces CO, HC, CO₂, PM, and PN emissions of gasoline vehicles.

关键词： Methanol fuel Vehicular emission Emission reduction Cleaner fuel Gasoline substitute

HTML PDF 收藏

Failure mode investigation of fuel cell for vehicle application

Zhongjun HOU, Renfang WANG, Keyong WANG, Weiyu SHI, Danming XING, Hongchun JIANG

《能源前沿（英文）》 2017年第11卷第3期页码 318-325 doi: 10.1007/s11708-017-0488-0

摘要： The durability of proton exchange membrane fuel cells (PEMFCs) has been posing a key technical challenge to commercial spread of fuel cell vehicles (FCVs). To improve the durability, it is necessary to optimize the fuel cell system (FCS) design against failure modes. The fuel cell durability research method at FCS scale was exhibited, and the failure modes of fuel cell were experimentally investigated in this paper. It is found that the fuel cell dry operation, start/stop cycle and gas diffusion layer (GDL) flooding are typical failure modes of fuel cells. After the modifications against the failure modes, the durability of FCSs is improved to over 3000 h step by step.

关键词： proton exchange membrane fuel cell (PEMFC) fuel cell system (FCS) durability failure mode fuel cell vehicle (FCV) carbon corrosion water management

HTML PDF 收藏

Numerical investigation of the effects of fuel spray type on the interaction of fuel spray and hot porous

ZHAO Zhiguo, XIE Maozhao

《能源前沿（英文）》 2008年第2卷第1期页码 59-65 doi: 10.1007/s11708-008-0022-5

摘要： The interaction between two types of fuel spray and a hot porous medium is studied numerically by using an improved version of KIVA-3V code. The improved KIVA-3V code is incorporated with an impingement model, a heat transfer model and a linearized instability sheet atomization (LISA) model to model the hollow cone spray. An evaporating fuel spray impingement on a hot plane surface was simulated under conditions of experiments performed by Senda to validate the reasonability of the KIVA-3V code. The numerical results conform well with experimental data for spray radius in the liquid and the vapor phases. Computational results on the interaction of two types of the fuel spray and the hot porous medium show that the fuel spray can be split, which provides conditions for quick evaporation of fuel droplets and mixing of fuel vapor with air. The possibility of fuel droplets from hollow cone spray crossing the porous medium reduces compared with that from solid cone spray, with the same initial kinetic energy of fuel droplets in both injection types.

关键词： improved version impingement atomization hollow radius

HTML PDF 收藏

Recent advances in cathode electrocatalysts for PEM fuel cells

Junliang ZHANG

《能源前沿（英文）》 2011年第5卷第2期页码 137-148 doi: 10.1007/s11708-011-0153-y

摘要： Great progress has been made in the past two decades in the development of the electrocatalysts for proton exchange membrane fuel cells (PEMFCs). This review article is focused on recent advances made in the kinetic-activity improvement on platinum- (Pt-) based cathode electrocatalysts for the oxygen reduction reaction (ORR). The origin of the limited ORR activity of Pt catalysts is discussed, followed by a review on the development of Pt alloy catalysts, Pt monolayer catalysts, and shape- and facet-controlled Pt-alloy nanocrystal catalysts. Mechanistic understanding is reviewed as well on the factors contributing to the enhanced ORR activity of these catalysts. Finally, future directions for PEMFC catalyst research are proposed.

关键词： proton exchange membrane fuel cells (PEMFCs) cathode electrocatalysts platinum oxygen reduction reaction (ORR)

HTML PDF 收藏

TiO supported IrO for anode reversal tolerance in proton exchange membrane fuel cell

《能源前沿（英文）》 2022年第16卷第5期页码 852-861 doi: 10.1007/s11708-021-0811-7

摘要： Fuel starvation can occur and cause damage to the cell when proton exchange membrane fuel cells operate under complex working conditions. In this case, carbon corrosion occurs. Oxygen evolution reaction (OER) catalysts can alleviate carbon corrosion by introducing water electrolysis at a lower potential at the anode in fuel shortage. The mixture of hydrogen oxidation reaction (HOR) and unsupported OER catalyst not only reduces the electrolysis efficiency, but also influences the initial performance of the fuel cell. Herein, Ti₄O₇ supported IrO_x is synthesized by utilizing the surfactant-assistant method and serves as reversal tolerant components in the anode. When the cell reverse time is less than 100 min, the cell voltage of the MEA added with IrO_x/Ti₄O₇ has almost no attenuation. Besides, the MEA has a longer reversal time (530 min) than IrO_x (75 min), showing an excellent reversal tolerance. The results of electron microscopy spectroscopy show that IrO_x particles have a good dispersity on the surface of Ti₄O₇ and IrO_x/Ti₄O₇ particles are uniformly dispersed on the anode catalytic layer. After the stability test, the Ti₄O₇ support has little decay, demonstrating a high electrochemical stability. IrO_x/Ti₄O₇ with a high dispersity has a great potential to the application on the reversal tolerance anode of the fuel cell.

关键词： proton exchange membrane fuel cell (PEMFC) fuel starvation cell reverse reversal tolerance anode oxygen evolution reaction

HTML PDF 收藏

基于图像处理的超高速撞击碎片云的动态建模与损伤估计 Research Article

曾入,宋燕,吕伟臻

《信息与电子工程前沿（英文）》 2022年第23卷第4期页码 555-570 doi: 10.1631/FITEE.2100049

摘要：由于难以从实验中获得高质量碎片云图像，对薄板上超高速撞击产生的碎片云进行轨迹建模和有效损伤估计一直是一项具有挑战性的任务。为提高超高速撞击对典型双层板防护结构损伤的估计精度，本文结合传统数值分析结果，利用图像处理技术，研究了连续阴影图中碎片云的分布特征。本文的目标是从图像处理获取的阴影图中提取碎片云的目标运动参数，并构建轨迹模型用来估计损伤。在超高速撞击实验中，我们从超高速序列激光阴影成像设备中获得8个连续阴影图片帧，从中选择4个具有代表性的帧用于后续特征分析。然后，利用去噪和分割等图像处理技术，从连续图像帧中提取特殊碎片特征。在提取的信息基础上，进行碎片图像匹配，并根据匹配的碎片对碎片云的轨迹进行建模。本文方法获得的结果与传统数值推导结果的对比表明，从图像处理中获取超高速撞击实验数据的方法可以为改进数值模拟方法提供关键信息。最后，基于所构建的模型，提出一种改进的后壁损伤估计方法。估计的损坏与后墙实际损坏情况的对比证明了所提模型的有效性。

关键词：碎片云；超高速撞击；图像处理；损伤估计

HTML PDF 收藏

Current challenge and perspective of PGM-free cathode catalysts for PEM fuel cells

Gang WU

《能源前沿（英文）》 2017年第11卷第3期页码 286-298 doi: 10.1007/s11708-017-0477-3

摘要： To significantly reduce the cost of proton exchange membrane fuel cells, platinum-group metal (PGM)-free cathode catalysts are highly desirable. Current M-N-C (M: Fe, Co or Mn) catalysts are considered the most promising due to their encouraging performance. The challenge thus has been their stability under acidic conditions, which has hindered their use for any practical applications. In this review, based on the author’s research experience in the field for more than 10 years, current challenges and possible solutions to overcome these problems were discussed. The current Edisonian approach (i.e., trial and error) to developing PGM-free catalysts has been ineffective in achieving revolutionary breakthroughs. Novel synthesis techniques based on a more methodological approach will enable atomic control and allow us to achieve optimal electronic and geometric structures for active sites uniformly dispersed within the 3D architectures. Structural and chemical controlled precursors such as metal-organic frameworks are highly desirable for making catalysts with an increased density of active sites and strengthening local bonding structures among N, C and metals. Advanced electrochemical and physical characterization, such as electron microscopy and X-ray absorption spectroscopy should be combined with first principle density functional theory (DFT) calculations to fully elucidate the active site structures.

关键词： oxygen reduction fuel cells cathode nonprecious metal catalysts carbon nanocomposites

HTML PDF 收藏

Renewable synthetic fuel: turning carbon dioxide back into fuel

《能源前沿（英文）》 2022年第16卷第2期页码 145-149 doi: 10.1007/s11708-022-0828-6

HTML PDF 收藏

A comprehensive assessment on the durability of gas diffusion electrode materials in PEM fuel cell stack

Arunkumar JAYAKUMAR

《能源前沿（英文）》 2019年第13卷第2期页码 325-338 doi: 10.1007/s11708-019-0618-y

摘要： Polymer electrolyte membrane (PEM) fuel cell is the most promising among the various types of fuel cells. Though it has found its applications in numerous fields, the cost and durability are key barriers impeding the commercialization of PEM fuel cell stack. The crucial and expensive component involved in it is the gas diffusion electrode (GDE) and its degradation, which limits the performance and life of the fuel cell stack. A critical analysis and comprehensive understanding of the structural and functional properties of various materials involved in the GDE can help us to address the related durability and cost issues. This paper reviews the key GDE components, and in specific, the root causes influencing the durability. It also envisages the role of novel materials and provides a critical recommendation to improve the GDE durability.

关键词： PEM fuel cell gas diffusion electrode(GDE) gas diffusion layer(GDL) membrane electrode assembly durability fuel cell catalyst

HTML PDF 收藏

A methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection

《能源前沿（英文）》 2023年第17卷第5期页码 678-691 doi: 10.1007/s11708-022-0859-z

摘要： Gasoline compression ignition (GCI) combustion faces problems such as high maximum pressure rise rate (MPRR) and combustion deterioration at high loads. This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection (DMI) strategy. Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation (EGR) on combustion and emissions. High-load experiments were conducted using the DMI strategy and compared with the single main-injection (SMI) strategy and conventional diesel combustion. The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode. At a 10 bar indicated mean effective pressure, increasing the main-injection-2 ratio (R_m-2) shortens the injection duration and increases the mean mixing time. Optimized R_m-2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions. An appropriate EGR should be adopted considering combustion and emissions. The DMI strategy achieves a highly efficient and stable combustion at high loads, with an indicated thermal efficiency (ITE) greater than 48%, CO and THC emissions at low levels, and MPRR within a reasonable range. Compared with the SMI strategy, the maximum improvement of the ITE is 1.5%, and the maximum reduction of MPRR is 1.5 bar/°CA.

关键词： gasoline compression ignition injection strategy fuel stratification high efficiency high load