Fe-Cr-Al电热合金气相反应原位生成绝缘膜的研究

利用气相反应在Fe-Cr-Al电热合金表面原位生成了耐高温的绝缘膜。绝缘膜主要由α-Al2O3相组成,膜的绝缘性良好,生长符合抛物线规律。另外研究了表面质量、氧压、反应时间及合金元素等因素对绝缘膜击穿性能的影响。     

NA123耐渗氮腐蚀的电热合金

本文介绍抗渗氮电热合金—NA123,与Ni80Cr20电热合金相比,其优点是具有高的电阻率、低的电阻温度系数、高的抗拉强度、延伸率和快速寿命值,尤其是它有高的抗渗氮能力。     

一种新型节能电热材料

<正> 1 引言各种电加热器是普遍使用的一类设备,尤其是500℃以下温区的加热器应用范围更广。加热器的关键元件是发热体。传统的加热器发热体几乎都是用金属电阻丝做成的。电阻丝因有明火,加热不均匀等缺点,在一些场合的应用受到限制。     

电阻炉电热元件使用寿命问题的热工方案的研究

以电阻炉中的电热元件和被加热元件为研究对象,经过简化提出简化模型,运用辐射换热理论对其进行了热工方面的理论计算和分析,在被加热元件热负荷一定的情况下,得出了影响电热元件温度的几大要点,提出了延长电热元件使用寿命的热工技术方案。     

一种从Al-Si活塞合金中除Ca的新方法

研究了一种从Al-Si活塞合金中除Ca的新方法.结果表明：向经P变质处理的合金熔体中加入Al-C中间合金能使Ca含量显著降低,并使P的变质效果得到恢复.     

改性材料电热元件应用于电热锅炉的研究

本文对用一种新型改性材料作为电热锅炉的加热元件进行了研究 ,并对影响该电热元件热力性能的各类因素作了较详尽的分析和探讨 ,提出了优化设计方案 ,旨在为电热锅炉电热元件的研究和设计提供理论依据。     

前途广阔的DZR电热材料

<正> 提起电热材料,人们自然会想到电炉丝,想到电炉、电熨斗、烘箱等电热设备和产品。的确,国计民生的各个方面都离不开它。然而,这些电热设备却都是耗电的"宠然大物",在能源供需矛盾突出的今天,人们自然希望能有一种新型低耗的电热材料取而代之。如果说电炉丝这种合金型的材料算是第一     

一种舒适的新型采暖方式——电热地暖系统

介绍了一种新型的电热地暖系统的组成、原理、优缺点及应用前景，并对其社会效益和经济性做了评价。     

电热锅炉用电热元件的设计制造

介绍了电热锅炉的主要元件──金属管状电热元件的设计制造。     

稀土铁铬铝合金的研究

电渣双联法生产稀土铁铬铝合金时,稀土在三相有衬电渣炉中的最佳加入量为0.5％。重熔后的残余含量在0.055％～0.075％时,合金的高温快速寿命比不加稀土的提高一倍左右,成材率、合格率有所提高,成本有所降低。     

提高滚丝模使用寿命的方法

在大批量生产的过程中,连杆螺钉的材料、硬度等要求的更改导致滚丝模使用寿命急剧缩短,从而导致生产成本过高。介绍从分析、试验到改进、完善,最终确定新的滚丝模制造工艺的过程。新滚丝模工艺大幅度地提高了滚丝模的使用寿命,保证了公司D114柴油机的生产进度。     

新型耐热钢T91的蠕变断裂寿命估算

T91 /P91钢是国外为提高火力发电机组的效率而研制的一种高合金耐热钢 ,它是完成超临界发电机组主蒸汽参数由 5 66℃向 5 93℃过渡的关键材料。采用受约束蠕变孔洞生长模型计算了不同试验条件下T91钢的蠕变断裂时间 ,计算值与实测值相差不到 2倍。在对模型修正后 ,计算得到的断裂时间与实际值更为接近 ,该模型可以用来估算T91钢高温服役条件下的蠕变断裂寿命     

Lifetime test of dropwise condensation on polymer-coated surfaces

In this paper, a special lifetime testing apparatus is installed for dropwise condensation heat transfer on polymer-coated surfaces. Film and dropwise condensations are simultaneously carried out in the same condensing chamber to get rid of any containments. The discontinuous experimental results demonstrate that one surface has sustained dropwise condensation for about 1000 hours. The condensation heat transfer characteristics tend toward stability. In addition, the experiments prove that a polymer film prepared by the dynamic ion-beam mixed implantation (DIMI) method has good adhesion with the metal substrate. © 1999 Scripta Technica, Heat Trans Asian Res, 28(7): 551–558, 1999     

Lifetime analysis of silicon solar cells by microwave reflection

Microwave photoconductive decay (μPCD) has become a standard technique for measuring the carrier lifetime of silicon used in solar cells. Here, we have used μPCD to examine the carrier lifetimes at common doping levels used in the base region of silicon photovoltaic devices. For the conductivity range used in the p-type base of n⁺–p structures, the microwave penetration depth is less than the wafer thickness. In this case, the reflectance–conductivity relationship is very nonlinear. We will show that quasi-steady-state photoconductivity (QSSPC) and resonance-coupled photoconductive decay (RCPCD) lifetime measurements track over a wide range of injection level, and generally agree at higher injection levels. Our μPCD data will be compared with the transient RCPCD data over the same range. The data from the latter agree at low-injection levels, but show serious disagreement at higher injection levels. The conclusion is that μPCD must be limited to low-injection levels in the doping range used for solar cells.     

基于寿命的电缆群载流能力优化研究

采用周期性条件计算得到的载流量能提高电缆的载流能力,在周期性载流量的基础上提出一种周期性寿命最大允许电流模型。鉴于电缆周期性寿命最大允许电流与电缆寿命之间互相影响,采用多目标粒子群算法,考虑电缆的互为热源效应,以电缆群的平均寿命和平均周期性寿命最大允许电流为目标函数,在改进周期性载流量设置方法的基础上提出周期性寿命最大允许电流设置方法,然后对电缆群中每条回路的周期性寿命最大允许电流和寿命进行优化,从而找到电缆群的优化运行方式,并深入研究了电热联合老化对两个目标函数的影响。     

Lifetime extension of in‐core self‐powered neutron detector using new emitter materials

In this paper, new in‐core self‐powered neutron detector emitter candidate materials, ie, vanadium, cobalt, and silver, have been examined in their lifetimes compared with the commonly used rhodium emitter. Using a new quantitative lifetime evaluation model, the lifetimes of vanadium and cobalt were determined to be longer than that of rhodium, but these materials were also shown to have the disadvantage of low signal intensities. Under normal operating conditions, we showed that rhodium emitter can be used for 2 cycles of pressurized water reactors (PWRs) with lifetime of 4.35 years, whereas silver can be used for 5 cycles of PWRs with lifetime of 8.04 years. Three sensitivity tests were performed for rhodium and silver about (1) the emitter size, (2) the fuel assembly burnup, and (3) the emitter temperature variations. From the test results, we observed that the lifetimes of rhodium and silver emitters remained 2 and 5 cycles long, respectively. We concluded that silver can significantly extend the in‐core detector's lifetime in PWR operation.     

Al-P中间合金的变质特性及变质机理探讨

通过在众多活塞厂家应用表明：A1-P中间合金无污染、无反应渣，变质效果好且稳定；节约能源，降低铝耗，综合成本低，克服了当前变质的缺点，有着广阔的应用前景。本文还探讨了A1-P中间合金的变质机理。