High Heat Flux Testing of B_4C/Cu and SiC/Cu Functionally Graded Materials Simulated by Laser and Electron Beam

B4C, SiC and C, Cu functionally graded-materials (FGMs) have been developed by plasma spraying and hot pressing. Their high-heat flux properties have been investigated by high energy laser and electron beam for the simulation of plasma disruption process of the future fusion reactors, And a study on eroded products of B4C/Cu FGM under transient thermal load of electron beam was performed. In the experiment, SEM and EDS analysis indicated that B4C and SiC were decomposed, carbon was preferentially evaporated under high thermal load, and a part of Si and Cu were melted, in addition, the splash of melted metal and the particle emission of brittle destruction were also found. Different erosive behaviors of carbon-based materials (CBMs) caused by laser and electron beam were also discussed.

Heat transfer performance testing of a new type of phase change heat sink for high power light emitting diode

In view of the limitations of solid metal heat sink in the heat dissipation of high power light emitting diode （LED）, a kind of miniaturized phase change heat sink is developed for high power LED packaging. First, the fabrication process of miniaturized phase change heat sink is investigated, upon which all parts of the heat sink are fabricated including main-body and end-cover of the heat sink, the formation of three-dimensional boiling structures at the evaporation end, the sintering of the wick, and the encapsulation of high power LED phase change heat sink. Subsequently, with the assistance of the developed testing system, heat transfer performance of the heat sink is tested under the condition of natural convection, upon which the influence of thermal load and working medium on the heat transfer performance is investigated. Finally, the heat transfer performance of the developed miniaturized phase change heat sink is compared with that of metal solid heat sink. Results show that the developed miniaturized phase change heat sink presents much better heat transfer performance over traditional metal solid heat sink, and is suitable for the packaging of high power LED.

Manufacturing and High Heat Flux Testing of Brazed Flat-Type W/CuCrZr Plasma Facing Components

Water-cooled flat-type W/Cu Cr Zr plasma facing components with an interlayer of oxygen-free copper（OFC） have been developed by using vacuum brazing route.The OFC layer for the accommodation of thermal stresses was cast onto the surface of W at a temperature range of 1150oC-1200 oC in a vacuum furnace.The W/OFC cast tiles were vacuum brazed to a Cu Cr Zr heat sink at 940 oC using the silver-free filler material Cu Mn Si Cr.The microstructure,bonding strength,and high heat flux properties of the brazed W/Cu Cr Zr joint samples were investigated.The W/Cu joint exhibits an average tensile strength of 134 MPa,which is about the same strength as pure annealed copper.High heat flux tests were performed in the electron beam facility EMS-60.Experimental results indicated that the brazed W/Cu Cr Zr mock-up experienced screening tests of up to 15 MW/m^2 and cyclic tests of 9 MW/m^2 for 1000 cycles without visible damage.

RAPID NONDESTRUCTIVE TESTING OF HEAT-TREATMENT QUALITY OF 2014 ALUMINIUM ALLOY

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Heating pulse tests under constant volume on Boom clay

Boom clay formation is a potential natural host rock for geological disposal of high-level nuclear waste in Belgium.Heating pulse tests with controlled power supply（maximum temperature was limited to 85℃） and controlled hydraulic boundary conditions were performed under nearly constant volume conditions to study the impact of thermal loading on the clay formation.Selected test results of intact borehole samples retrieved in horizontal direction are presented and discussed.The study focuses on the time evolution of temperature and pore water pressure changes along heating and cooling paths,i.e.pore pressure build-up during quasi-undrained heating and later dissipation at constant temperature.

Preliminary High Heat Flux Tests of Small-Scale Be/Cu Mock-Ups

China, as one of the members of ITER （international thermonuclear experimental reactor） project, one of the most important construction tasks is the fabrication of the first wall panel and shield blankets, which is the key engineering technology of ITER construction and might be one of the crucial issues of the future reactor too. Since 2004, an associated research team including Southwestern Institute of Physics （ SWIP ）, Ninxia Non-ferrous Metal Co. Itd and Chinese Institute of Engineering Physics, as well as Nuclear Power Institute of China has been established. Up to now, several series of interlayer for hot isostatic press （ HIP ） connection of beryllium and CuCrZr alloy have been tested. They are titanium film or coating, Cu coating and Al or AISiMg alloy etc. The bonding strength （tensile or shear strength ） of HIPed Be/Cu joints is up to 100 MPa.

Feasibility of Prototyping the Jominy Test Device: Corroborating for Studies and Preliminary Results of the Heating and Data Acquisition Subsystems

This work contributed to a detailed study on a better understanding of the Jominy test, adopted a proportion of study to create the Jominy test device, exhibited favorable conceptions for the development of a prototype of the device, covering the four aspects of the project, being they: test device, test body heating system, test automation and instrumentation using embedded electronics and financial analysis for the elaboration of this project in Brazil. It was possible to observe in the results that the system is efficient, simple and functional, it was possible to obtain the first test carried out in the controlled environment the temperature data in degrees centigrade, the recorded data were automatically launched in Microsoft Excel by the PLX DAQ software, making the acquisition of the data. In the matter of preparing the test device, the drawings are presented in the 3D modeling software, cost tables of the materials used for assembly in Brazil. In terms of the heating system, a heating system was adopted that uses electromagnetic induction, the cost of materials related to the heating system design was also presented. Another relevant factor that contributes to the research and improvement of the prototype is the municipality, located in the Paraiba Valley region, located in the state of São Paulo, consisting of a fertile and relevant scenario of regional, national, international and multinational statistics, thus concluding the effectiveness for the mainly metallurgical industries. The results obtained were satisfactory and consistent, when they were created for the Jominy test device with the ability to submit small pieces for testing and mainly essential in the didactic point of view for a higher education institution of engineering and technology.

Parallel Correlative Study of the Heat Balance Test Process for Testing the Efficiency of Turbo-Generators

In order to prolong the life span of a turbo-generator plant and sustain its performance at high efficiency, it is subjected periodically to regular test to monitor the operational profile and efficiency of power conversion from mechanical energy to electrical energy. Analysis of these test data serves as a measure to indicate deviation from normal operation profile and deterioration of plant performance. This present work implemented the heat balance tests process to three turb- generator units in order to assess the harmony, consistency, and accuracy of results to establish parallel correlation for the test process. The test process involves carrying out a heat balance for the turbo-generators at 50%, 75% and 100% load respectively through the determination of the heat losses through the hydrogen coolers, bearing oil, seal oil and radiation and convention to the atmosphere. Some important results were presented in the paper.

高温气冷堆热态功能试验中一回路加热动态特性研究

高温气冷堆反应堆压力容器堆内构件由石墨和碳化硼烧结陶瓷材料组成,热态功能试验过程中需对一回路堆内构件进行加热除湿。针对高温气冷堆一回路热试系统特点,采用COMSOL Multiphysics 5.4计算软件构建了压力容器、蒸汽发生器和主氦风机三维数值模型,并通过示范工程加热试验值验证了模型的可靠性,并获得了一回路加热过程中温度场动态特性。为了解决高温气冷堆示范工程一回路首次加热效率低的问题,提出了将辅助蒸汽通入到蒸汽发生器,并动态调整辅助蒸汽运行参数来加热一回路氦气的方法,结果表明:相较于主氦风机单独加热方式,外加辅助蒸汽热源可节省加热时间约31.3 h,同时可将堆芯最终平衡温度由250℃提高至265℃;在满足运行准则的前提下,更有利于碳砖和石墨堆内构件的除湿。该研究结果为高温气冷堆一回路热试提供了有力支持。

太阳能耦合充填体热泵跨季节蓄热系统影响因素

为明确太阳能耦合充填体热泵跨季节蓄热系统参数,选取对充填体温度场变化和蓄/释热效果的影响,通过正交试验法对集热器面积、蓄热水箱体积与集热器面积比、充填体导热系数、地埋管管间距、埋管管材导热系数进行多因素研究,通过建筑负荷对太阳能耦合充填体热泵跨季节蓄热系统进行设计并采用TRNSYS软件建模,开展五水平五因素正交试验,通过选择系统蓄热率以及蓄热耗电比2个指标得出最优参数方案并进行10 a运行模拟。结果表明:集热器面积和充填体导热系数变化对充填体蓄热率有显著影响,蓄热水箱体积与集热器面积比则对其基本无影响;集热器面积和充填体导热系数以及埋管管材导热系数对蓄热耗电比有显著影响,蓄热水箱体积与集热器面积比和地埋管管间距则对其影响程度很小;将优化后的方案与原方案进行对比,蓄热率提高了12.65%;蓄热耗电比降低了28.17%,集热器集热量和充填体蓄热量分别提高了30.73%和39.49%。优化后系统应用价值显著提升,为后期研究太阳能耦合充填体热泵系统提供理论支持。

即食脆肠中主要残留菌的鉴定及联合调控

[目的]探究脆肠中的主要残留细菌,并进行有效控制。[方法]利用16S rDNA技术鉴定脆肠中的主要残留菌,通过高温筛选出耐热性强的优势腐败菌进行复合抗菌试验。[结果]原辅料、脆肠成品、腐败样品等5组样品中共分离出47株残留菌,隶属8个属,分别为芽孢杆菌属(Bacillus)、链球菌属(Streptococcus)、莫拉菌属(Moraxella)、嗜盐碱芽孢杆菌属(Alkalihalobacillus)、库特氏菌属(Kurthia)、乳球菌属(Lactococcus)、肠球菌属(Enterococcus)及漫游球菌属(Vagococcus)。脆肠进行拌料时用的配料酱带有芽孢杆菌,易引入二次污染。经高温灭菌仍残留部分优势腐败菌,与腐败脆肠的主要残留菌同为芽孢杆菌属,其中芽孢杆菌属C7-1和C8-3的耐热性最强;通过添加0.2 g/kgε-聚赖氨酸和0.5 g/kg的柠檬酸能有效抑制两种芽孢杆菌的生长。[结论]即食脆肠产品添加0.2 g/kgε-聚赖氨酸和0.5 g/kg的柠檬酸并结合110℃高温杀菌10 min,(36±2)℃保藏30 d未出现腐败胀袋现象。

基于恒热流法和恒温法的岩土热物性试验分析研究

目前岩土热物性测试仪采用的方法包括两种:恒热流法和恒温法,通过介绍两种测试方法的区别及模型算法,以北京市某公建项目岩土热物性测试结果为基准,利用TRNSYS软件分别模拟了恒热流法和恒温法的测试工况,针对模拟结果展开分析研究。经对比,试验时间至48 h时,两种测试方法利用软件模拟出的延米换热量与现场测试结果的误差在10%以内,表明若已知项目周边的地层热物性参数如地层的导热系数、热扩散率等,可将软件模拟结果作为前期地埋管系统设计的依据,并作为后续热物性勘察结果验证的参考数据。此外,根据模拟结果,由于夏季地埋管流体在设计工况下与土壤的温差值较大,为了使流体尽快达到设计工况点,恒温法测试时应选用较大的功率,否则48 h内的测试值结果与实际值偏差较大。

风力发电机叶片防除冰涂层(二):温升数值计算及防除冰性能

针对电热超疏水涂层覆冰过程中表现出的三类不同冰层形貌,该文建立了电加热融冰数值计算模型,并对仿真计算结果进行了相应的试验验证,验证结果与仿真结果基本一致,该模型能有效模拟融冰过程和温度分布。临界融冰功率的计算结果表明,电热超疏水涂层融冰所需功率大于非超疏水电热涂层,尤其在乳突状冰层出现后,融冰功率将大幅增加。电热超疏水涂层防冰试验结果表明,在雨凇覆冰环境中,超疏水性能单独作用时,叶片在覆冰前期能延缓覆冰;电热性能与超疏水性能共同作用时,叶片无覆冰形成。电热超疏水涂层用于风力发电机防覆冰具有较好的效果,但用于覆冰后的融冰时将需要更多的能量。

基于热模型相关性验证的火面环境热平衡试验

针对热平衡试验中难以综合模拟火面复杂多变服役热环境的困难,建立一种基于热模型相关性验证的热平衡试验方法。采用真空、低压变温自然对流和低压定温强迫对流验证相结合的方式,验证高低温条件下热分析模型的对流、导热、辐射网络系数和热容等参数,并由相关性检验后的热分析模型验证设计的正确性。结果表明,板温度高于气温11~86℃条件下(气温-91℃)的自然对流传热系数为0.19~0.57 W/(m^(2)·K),4~15 m/s风速下的强迫对流换热系数为1.24~2.4 W/(m^(2)·K)修正后的热分析模型与试验结果偏差在±3.5℃以内。该方法在不完全模拟服役热环境条件下实现航天器热设计验证,提供有效的热分析模型,已成功应用于祝融号火星车热平衡试验。

基于正交试验法的太阳能复合热水系统优化

为降低生活热水能耗,实现空气源热泵辅助太阳能供热水系统的高效节能运行,选取济南市某高校学生宿舍空气源热泵辅助太阳能供热水系统作为研究对象,利用瞬时系统模拟软件搭建了系统仿真模型,并采用无交互作用的正交试验法,分别以全年系统性能系数和太阳能保证率为优化目标,优化了太阳能集热器面积、集热器倾角、热泵制热功率及水箱容积,并分析其结果的经济性和节能性。结果表明:当以系统性能系数为优化目标时,最优组合中集热器面积为390 m^(2)、集热器倾角为42°、热泵制热功率为50 kW、水箱容积为23.94 m3,而动态费用年值为7.38万元,较天然气系统年节省标煤为17.12 tce;当以太阳能保证率为优化目标时,最优组合中集热器面积为342 m^(2)、集热器倾角为44°、热泵制热功率为35.5 kW、水箱容积为20.58 m3,而动态费用年值为6.56万元,较天然气系统年节省标煤为16.63 tce。

间歇式运行模式下黄土地基中能量桩热-力特性模型试验

能量桩是将传统桩基与地源热泵相结合的一种建筑节能新技术。为研究黄土地层中能量桩热交换效率及承载变形特性,了解黄土饱和状态对能量桩热交换效率、桩土温度、桩土沉降及桩身轴力、摩阻力的影响规律,开展间歇式运行模式下黄土处于天然湿密状态及饱和状态的能量桩模型试验。试验采用的黄土为人工配制黄土,模型桩为内置单U形换热管的现浇钢筋混凝土桩。试验结果表明:黄土中能量桩具有较高的热交换效率,黄土饱和时能量桩的热交换效率大于黄土处于天然湿密状态,随着无量纲直径D/L的增大,能量桩的热交换效率增加。不论黄土处于天然湿密状态还是饱和状态,桩顶沉降呈现出棘轮形式并随冷热循环次数增加逐渐增大。热循环、冷循环对能量桩的承载力影响不同,经过每一个完整的冷热循环后,桩的承载力均降低了。该文还建立了计算能量桩热交换效率的新公式,该公式考虑了桩身侧表面积及循环液与初始地温差的影响。

局部受热锈蚀预应力混凝土梁力学性能试验研究

随着我国基础建设的发展,大量混凝土桥梁在恶劣环境影响下发生腐蚀和老化,腐蚀桥梁结构的灾害破坏机理研究对桥梁结构的运营安全具有重要意义。为研究已经锈蚀受损的桥梁在局部受热状态下的高温力学性能,设计10根预应力混凝土梁试件。其中对照组的2根试件在常温下加载,试验变量为预应力筋初始应力,试验组的8根试件在高温下加载,试验变量分别为钢筋锈蚀、预应力筋初始应力、初始荷载。首先,基于电化学原理对4根预应力混凝土梁进行钢筋加速锈蚀处理,然后利用复合高温试验炉对8根预应力混凝土梁(4根锈蚀、4根未锈蚀)在跨中进行三面受火试验。最后,采用数值方法对局部受热预应力混凝土梁进行了仿真分析。研究结果表明:局部受热条件下,预应力混凝土梁的承载能力会发生明显降低,下降幅度约为11.3%~14.9%;钢筋锈蚀导致的混凝土开裂会对预应力混凝土梁的抗火性能产生不利影响,主要表现为2个方面,1)相同试验条件下,锈蚀后的试件预应力增量更大;2)锈蚀试件在局部受热条件下承载能力下降幅度更大,约为19.4%~21.9%;增大预应力筋的初始应力可以减小预应力混凝土梁在局部受热时的高温蠕变变形;局部高温作用下预应力混凝土梁对初始荷载较为敏感,当试件初始荷载值提升20%时,三分点位移量约增大60%。研究成果可以为实际锈蚀桥梁的防火设计和灾后应急提供理论依据。

150BS抑制基础油热管氧化沉积物及其机理探究

为了降低活塞表面沉积物,提高发动机活塞清净性,采用热管氧化试验法对Ib150、150BS基础油开展氧化沉积物试验,利用傅里叶变换红外吸收光谱仪(FT-IR)、扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X射线光电子能谱(XPS)、磁共振氢谱(^(1)H NMR)对管壁沉积物进行表征。试验结果表明:0%150BS试样管壁氧化沉积物最多;9%150BS试样管壁氧化沉积物最少,且沉积物中的碳元素、硫元素含量最少,氧元素含量最多。机理分析结果表明:随着150BS基础油含量增加,提高了基础油组合物中自由基相互碰撞概率,抑制了Ib150基础油自由基产生,减少了管壁沉积物形成。同时,随着更多150BS基础油的加入,也促使Ib150基础油深度氧化,导致管壁沉积物中碳基官能团增加且酯类化合物发生重排,从而使沉积物中氧元素含量增加,但更多的硫元素以SO_(x)形式随空气溢出。

HSD类黏指剂热管氧化沉积物形成与表征

采用热管氧化试验法分别对单一基础油和1wt.%HSD类黏度指数改进剂[ω(氢化苯乙烯双烯共聚物):ω(基础油)=1∶99]在220℃、250℃、280℃、310℃温度下开展试验,并利用SEM、EDS、FT IR、1H-NMR对管壁沉积物进行表征。研究表明:在220℃、250℃试验温度下,单一基础油形成管壁沉积物含量高,在280℃、310℃试验温度下,1wt.%HSD黏度指数改进剂形成管壁沉积物含量明显高于单一基础油。与220℃、280℃试验温度下的管壁沉积物相比,1wt.%HSD黏度指数改进剂在280℃、310℃下的管壁沉积物平均粒径90~100μm,沉积物的O、S含量相近,C元素含量略有增加。另外,管壁沉积物化学位移0.85×10^(-6)峰面积明显增大,但化学位移1.26×10^(-6)、1.56×10^(-6)峰面积明显变小。由此说明,1wt.%HSD类黏度指数改进剂中烷烃链长变短,但异构化程度显著增加。这可能是因为HSD类黏度指数改进剂在280℃、310℃温度下发生深度氧化引起的。

井口除砂器抗冲蚀性能评价分析

含砂天然气对井口除砂器部件会造成严重的冲蚀进而降低开采效率,并且留下安全隐患。针对除砂器关键部件冲蚀严重的问题,从冲蚀角度和热处理2个方面研究其关键部件的耐冲蚀材料42CrMo、45钢、2Cr13、20CrMnTi和H13(4Cr5MoSiV1)的抗冲蚀性能。首先搭建冲蚀试验平台进行了冲蚀模拟试验,其次利用扫描电镜观察靶材冲蚀后的微观形貌,探讨冲蚀磨损机理。结果表明:当冲蚀角在30°~90°时,冲蚀率随冲蚀角的增加而减小;并非所有材料经热处理都能提高抗冲蚀性能;调质状态的2Cr13的抗冲蚀性能最优;调质状态的2Cr13、45钢和出厂状态的H13倾斜冲击时磨损形式以切削为主,垂直冲击时磨损形式为磨料冲击使靶材发生塑性变形而脱落为主。本试验为除砂器耐蚀件选材提供了参考。