Effect of W-addition on low cycle fatigue behavior of high Cr ferritic steels

A study was done to investigate the effect of tungsten (W) addition on the microstructure, tensile properties and low cycle fatigue (LCF) properties of 9Cr-lMo steels at 298K and 873K. Four steels containing different amounts of W (0W, 1.2W, 1.8W and 2.7W) were normalized at 1323K for 1 hour and tempered at 1023K for 1 hour. Microstructural analysis revealed that no significant differences wete observed in their tempered martensitic microstructure of 0W, 1.2W and 1.8W alloys, but d-ferrite was observed to form at the prior austenite grain boundaries of the 2.7W alloy. With the increase in W content, yield and tensile strength increased at both temperatures. Low cycle fatigue life also increased with the W content up to 1.8%, but decreased in the 2.7W alloy, which was primarily due to the presence of soft d-ferrite acting as the crack initiation site. The fatigue life at 873K was reduced compared to that at 298K, due not only to the decrease in strength at high temperature but also to the formation of oxide layers along the slip bands, which increases slip irre-versibility during cyclic deformation. This article based on a presentation made in the symposium “The 1^st Korea—Japan Structural Dynamic Symposium”, held at Sunchon National University, Sunchon, Korea, August 5–8, 1999 under the auspices of The Korean Insitute of Metals and Materials and Research and Development Center for Automobile Parts and Materials.     

水冷螺杆机组热回收的设计与应用

以水冷螺杆机组的热回收机制为研究基础,对影响热回收效率的几个重要因素进行详细的比较分析,确定相关因素的影响规律,并提出改善热回收设计与应用的措施。     

苏14井区丛式井实施效果分析

通过2007年苏里格气田苏14井区8口丛式井现场实施效果跟踪。对钻井时效、防碰技术、单井设计基本参数及其计算、钻具组合、最佳造斜点、钻井液技术和实钻中地质复杂情况分析总结。为2008年苏里格气田大规模丛式井开发提供了可靠数据,也是节约土地、规避安全风险、控降成本的有效途径。因此,大力试验、认真总结、全面推广天然气丛式井开发会产生很大的经济和社会效益。     

Hydrogen production via water splitting process in a molten-salt fusion breeder

This study presents the hydrogen production and fissile breeding potentials of Force-Free Helical Reactor (FFHR) fueled with the molten-salt mixtures. The sulfur–iodine (S–I) thermochemical water-splitting and high-temperature electrolysis cycles, which are the most promising water-splitting cycles, are selected to produce large-scale and pure hydrogen. The XSDRNPM/SCALE4.4a neutron transport code is used for the neutronic calculations. The analyses have been performed individually for four different molten-salt mixtures, (pure FLiBe, mixture of FLiBe and ThF₄, mixture of FLiBe and UF₄, and mixture of FLiBe, ThF₄ and ²³³UF₄). The numerical results bring out that the considered molten-salt fusion breeder reactor has a high neutronic performance and can produce a considerable amount of the hydrogen production (up to 40 kg/s), as well as the fissile fuel (up to 2.5 tons/yr).     

清洁化生产的基本概念及其实施策略

将可持续发展，系统集成的思想以及产品寿命循环分析的方法结合起来，给出了清洁化生产的定义，并在此基础上详细分析了清洁化生产的特点和意义。结合我国的具体情况，对在我国实施清洁化生产战略提出了一些具体建议。     

R＆D and Application of Catalyst for Resid Hydrotreating in Upflow Reactor

In order to extend the operating cycle of the upflow reactor for resid hydrotreating, the Research Institute of Petroleum Processing taking into account the specifics of resid hydrotreating upflow reactor has developed the high-performance RUF series of catalysts suitable for operation in the upflow reactor. The results of commercial application of catalysts revealed that this RUF series of catalysts loaded after optimized grading could effectively remove metals, sulfur and carbon residue from the residuum to provide improved oil for the following fixed-bed reactor. In the meantime, the RUF series of catalysts have excellent stability to reach an operating cycle of 1.5 years, resulting in minimization of losses caused by refinery downtime.     

Design‐based life cycle assessment of hazardous air pollutant control options at pulp and paper mills: a comparison of thermal oxidation to photocatalytic oxidation and biofiltration

BACKGROUND: The forest products industry produces valuable industrial chemicals, wood products, and consumer goods, but is also responsible for the emission of significant quantities of hazardous air pollutants. Although many air pollution control options are available, little is known about the overall environmental impacts of implementing each option. Therefore, a life cycle assessment (LCA) was conducted to compare energy and raw material inputs, air emissions, and environmental impacts associated with construction and operation of two air pollution control systems: regenerative thermal oxidation (RTO) with wet scrubbing and photocatalytic oxidation (PCO) with biofiltration. RESULTS: LCA results indicated that environmental impacts to resource depletion, photochemical oxidant formation, and acidification were 20% higher for the use of a RTO‐scrubber than for the PCO‐biofilter. In addition, at least 25% of the RTO impacts were due to infrastructure requirements. However, the PCO‐biofilter system was responsible for more environmental impact in categories of global warming and human toxicity, because of the packing materials required and the electricity use for the PCO reactor. CONCLUSIONS: The PCO‐biofilter system could be a promising, environmentally‐friendly alternative to traditional RTO devices, provided that this system is modified to decrease resource and energy demands. Copyright © 2008 Society of Chemical Industry     

Efficiency of hydrogen internal combustion engine combined with open steam Rankine cycle recovering water and waste heat

A hydrogen internal combustion engine (HICE) wastes more heat, and producing nearly three times more water than a conventional engine. This paper describes the principle behind a novel waste heat recovery sub-system that exploits the water produced by an HICE as the working fluid for an open-cycle power generation system based on the Rankine cycle. Water from the HICE exhaust is superheated by the waste heat from the HICE and used to produce power in a steam expander. A fundamental thermodynamic model shows the contribution of the sub-system to the overall thermal efficiency of the HICE at various engine speeds, with and without a condenser. The results show that the condenser is not cost-effective and that the overall thermal efficiency with the proposed sub-system is 27.2% to 33.6%, representing improvements of 2.9% to 3.7%, at engine speeds of 1500 to 4500 rpm.     

“华中”与“FANUC”数控系统“G76”指令使用的异同

以编程示例的方式，对国产的武汉“华中”数控系统与日本“FANUC”数控系统的螺纹切削复合循环指令G76进行对比，明确二者之间的区别与联系，避免使用时出现错误。     

闭式循环柴油机性能的试验研究

在闭式循环柴油机开式运行和闭式运行时,通过改变超重力旋转床的水流量,对吸收器的吸收特性及其闭式循环柴油机性能的影响进行了分析.恒定柴油机负载,改变混合进气中氩气的含量,分析了进气混合气中氩气含量对闭式循环柴油机性能的影响.在闭式运行时进行负荷试验,并与开式对比,对开式运行和闭式运行的油耗、系统压力等参数及柴油机运行状况进行了对比分析.