连续碳分CO2吸收率分析及探讨

本文简述了CO2 气体吸收率的测定原理 ,着重分析了影响连续碳分CO2 气体吸收率的因素 ,提出了提高连续碳分CO2 气体吸收率的途径     

钛合金带热沉钨极氩弧焊中热沉作用

采用数值模拟和实验相结合的方法研究了钛合金TC4薄板常规及带热沉的钨极氩弧焊焊接过程中温度及应力应变的分布,考察了热沉对温度场和应力应变场的影响规律,探讨了使用该技术实现应力和变形控制的机理.结果表明:带热沉的钨极氩弧焊焊接过程中,紧随热源之后热沉急冷作用使得试件形成马鞍形温度场,而热沉作用部位温度最低.热沉作用部位的急冷收缩对周围金属产生拉伸作用,使得焊缝及近缝区金属升温过程中产生的压缩塑性应变减小,冷却过程中产生的拉伸塑性应变增大,接头中不协调应变减小,残余应力降低.实验测量与有限元模拟结果吻合良好,证实了采用热沉控制应力与变形的有效性和有限元模型的正确性.     

蒸发法制备Ni－Ti纳米非晶合金粒子

采用气相蒸发法制备纳米量级的Ｎｉ－Ｔｉ非晶合金粒子，研究了各种因素对Ｎｉ－Ｔｉ纳米非晶合金粒子形成的影响，并用透射电子显微镜，高分辨电子显微镜，Ｘ射线衍射仪和能谱等多种手段对纳米非晶合金粒子进行了表征．结果表明，当粒子成分在共晶区Ｎｉ（４０）Ｔｉ（６０）附近时，容易形成非晶；较低惰性气体压力和较高蒸发温度有利于Ｎｉ－Ｔｉ纳米非晶粒子的形成．     

超声振动辅助气中放电加工实验分析

超声振动辅助气中放电加工技术避免了常用的煤油等工作液作为介质带来的环境污染问题，具有工作环境清洁、适用范围广、加工效率高、工具电极简单等优点。实验研究了电压、脉冲宽度、峰值电流、超声振幅及气体介质压力等参数对加工效率、工件表面粗糙度及电极损耗的影响．并对试验结果进行了分析。     

TBC experience in land- based gas turbines

This paper summarizes prior and on-going machine evaluations of thermal barrier coatings (TBC) for power generation, that is large industrial gas turbine applications. Rainbow testing of TBCs on turbine nozzles, shrouds, and buckets are described along with a test of combustor liners. General Electric Power Generation has conducted more than IS machine tests on TBC turbine nozzles with various coatings. TBC performance has been quite good, and additional testing, including TBCs on shrouds and buckets, is continuing. Included is a brief comparison of TBC requirements for power generation and aircraft turbines.     

低气压等离子喷涂TiO2涂层结构的研究

本研究分析了在低气压等离子喷涂条件下,TiO_2涂层的结构受等离子弧喷涂过程中氧分解量所影响。氧分解量很大程度上依赖于离子气中氢流量的大小,此外喷涂室压力也有一定影响。而等离子弧功率和喷涂距离对TiO_2涂层的氧分解量没有多大影响。在离子气中氢流量不变的条件下,涂层中Ti_3O_5量随喷涂室压力(从100×133.322Pa至400×133.322Pa)增加而增加。     

Numerical modeling of in-flight characteristics of inconel 625 particles during high-velocity oxy-fuel thermal spraying

A computational fluid dynamics (CFD) model is developed to predict particle dynamic behavior in a high-velocity oxyfuel (HVOF) thermal spray gun in which premixed oxygen and propylene are burnt in a combustion chamber linked to a long, parallel-sided nozzle. The particle transport equations are solved in a Lagrangian manner and coupled with the two-dimensional, axisymmetric, steady state, chemically reacting, turbulent gas flow. Within the particle transport model, the total flow of the particle phase is modeled by tracking a small number of particles through the continuum gas flow, and each of these individual particles is tracked independently through the continuous phase. Three different combustion chamber designs were modeled, and the in-flight particle characteristics of Inconel were 625 studied. Results are presented to show the effect of process parameters, such as particle injection speed and location, total gas flow rate, fuel-to-oxygen gas ratio, and particle size on the particle dynamic behavior for a parallel-sided, 12 mm long combustion chamber. The results indicate that the momentum and heat transfer to particles are primarily influenced by total gas flow. The 12 mm long chamber can achieve an optimum performance for Inconel 625 powder particles ranging in diameter from 20 to 40 μm. At a particular spraying distance, an optimal size of particles is observed with respect to particle temperature. The effect of different combustion chamber dimensions on particle dynamics was also investigated. The results obtained for both a 22 mm long chamber and also one with a conical, converging design are compared with the baseline data for the 12 mm chamber.     

Rapid and Continuous Deposition of Porous Nanocrystalline SnO2 Coating with Interpenetrating Pores for Gas Sensor Applications

In this article, we proposed a rapid and continuous process for the production of nanoporous coatings for functional applications. Experiments following two statistical designs were implemented to screen and investigate the spraying parameters’ effects on coating crystallinity and porosity in order to gain a better understanding. The spraying standoff distance, solution flow rate and power were identified as having significant effects on coating porosity and crystallinity. The result yielded a peculiar microstructure comprised of interpenetrating pores and layered structures with embedded pores. A deposition mechanism was postulated to explain this microstructure. Ethanol gas sensors that are constructed from the coatings had comparable sensitivities to those reported in the literature for thick-film coatings and had a maximum sensitivity near 200 °C. This article is an invited paper selected from presentations at the 2007 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Global Coating Solutions, Proceedings of the 2007 International Thermal Spray Conference, Beijing, China, May 14-16, 2007, Basil R. Marple, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2007.     

一起变压器油气在线监测装置报警故障的分析及处理

鉴于一起220 k V变压器油气在线监测装置的报警故障,对变压器油的色谱数据进行了分析,对2号主变压器进行吊罩检查,结果表明:故障因变压器梯级绝缘垫块结构设计存在缺陷,在运行中逐步造成垫块松动、脱落所致,并提出了处理措施。     

Method of calculating the collision integral and solution of the Boltzmann kinetic equation for simple gases,gas mixtures and gases with rotational degrees of freedom

The conservative method of calculating the Boltzmann collision integral for simple gases, gas mixtures and gases with rotational degrees of freedom of molecules is presented. In all cases the common approach based on the projection technique of summing up the contributions in the collision integral is used. The method is applied for solving the Boltzmann kinetic equation for two fundamental rarefied gas flow problems: the heat transfer problem and the problem of shock wave structure. A comparison with experimental and numerical data of other authors is reported. It is shown that the considered numerical method allows one to solve the Boltzmann equation for real gases with high accuracy.