日本精车机床RL—1—NC故障的排除

前言我厂于 1 985年引进两台日本片冈公司带FANUC- 2 M+分离型 PLC数控系统的 RL- 1 -NC型车床 ,用于活塞环车锥、扭边、鼻形、切槽等异型环的加工。国内同行业企业引进的还有四台。在这里我们对该机床近期出现两次数控系统故障作一概述。2　故障一 :锂电池引起的数控故障2 .1　现象正常停机一个班次后 ,打开控制柜电源 ,操作NC- POWER ON按钮 ,CRT显示如下画面 :O0 0 0 1N0 0 10X 5 0 .0 0 0Y 0 0 .0 0 0Z 10 .0 0 0Not　 ready(闪烁 )not ready闪烁 ,即控制系统未准备好故障报警 ,油泵电机不启动。按键 ALARM转到报警画面 …     

Desulfurization in Reducing Atomosphere and Ammonia Injection Denitrification in a Coal—Fired Fluidized Bed COmbustor with FLy—Ash Recycle

INTR0DUCTIONWiththedevel0pmentofthesec0ndgenerati0nPFBC-CCandIGCCtechnologies,thedesulfuriza-tionunderthereducingatmosphereisputf0rward.Whencoalburnsunderthelowexcessaircoeffi-cient,H2Sisgeneratedandthenf0rmscalciumsulfide(CaS).Becausethem0larvolumeofCaSissmallerthanthatofCaCO3,thediffusionresistanceissmallandthep0re-blockingphen0menond0esn'tappear.Therefore,theutilizationrateofcalciumanddesulfu-rizationefficiencyisraisedremarkably[1,2l3].InChina,aPFBCpil0tpowerplantisbeingcon-st…     

Photographic Study of Obstacle—Induced Disturbations of Transonic Turbine Cascade Flow

INTRoDUCTIONTheturbineandtalalcompressorcascadeflowsarestronglyeduellcedbyb0ththeupstreamanddown-8treamunsteadybotmdaryconditions.Theunsteadi-ness0fthesllowsisduetotherelativemotionofthestatorandrotorblades.Thispr0blemhasbeeninVeSigatednumericallyandexperimelltallyforovertenyears.ThemajorityofthepapersconsideredtheeffectofuPstreamb0undaryconditions.Sharmaetal.(1992)estAnatedthatthewakesandtheshockwavesatthetrailinedgesofthestatorcascadecausethelossesofther0torcascadefiownearlytwiceaslarg…     

Al—P中间合金对Al—Si合金的“绿色”变质

用 Al- 3P中间合金对 ZL1 0 9合金进行了变质生产试验 ,研究了其在生产中的工艺参数及加入工艺。对共晶成分的 Al- Si合金 ,其加入量按 W原料 × ( 0 .4%～ 0 .45 % ) + W回炉料 × 0 .1 %=WAl-3 P中间合金 进行计算称量 ,在 760～ 770℃变质即可取得良好的变质效果 ,生产出品质优良的活塞铸件。使用 Al- P中间合金变质剂加入方便 ,无渣无污染 ,可以提高合金的实收率、降低生产综合成本 ,适于工业化生产应用 ,是磷盐变质剂良好的替代品。     

Close—COntact Melting Around a Hot Sphere

INTRODUCTIONClose-contactmeltingoccurswhenaphasechangematerial(PCM)solidispressedagainstahotsurfacethathasatemperatureabovethePCMmeltingpoint.Althoughthisphenomenoncanbefoundinmanydifferentareassuchasspacecraftandnucleartechnol-ogy,latentheatthermalstoragesystems,geophysics,materialsprocessing,etc.,t0studyitasaspecificim-portantheattransferregimeonlybeginsintheearlyeighties.BetweenthePCMandtheheatedsurfacetherealw8ysekistsaliquidfilminwhichthemeltedliquidiscontinuouslysqueezedout.Theco…     

波兰产TK—120型汽轮机的增效与安全改造

针对田家庵发电厂波兰产的 1号、2号 (TK - 12 0 )汽轮机的现运行情况 ,实施了对汽轮机中压缸、转子及轴封系统的改造工程。使中压缸的内效率由 85 .6 9%提高到 91.96 % ,整机热耗由 92 94.1kJ/ (kW·h)降低到 90 85 .18kJ/ (kW·h) ,汽轮机前端轴瓦振动由 0 .0 5mm降低到 0 .0 0 8mm ,汽轮机后端轴瓦振动由 0 .10mm降低到 0 .0 12mm ,汽轮机推力瓦温度由 98℃降低到 77℃ ,机组轴封系统达到设计标准。机组改造后综合安全性能得到了保证 ,热效率明显提高 ,获得了良好的经济和社会效益     

Laminar Natural Convective Heat Transfer in the Enclosed Evacuated Collector Tube with East—West Symmetric Heat Input

INTR0DUCTI0NNaturalconvectioninenclosureshasbeenfoundinavariety0fapplications,suchassolarcollectors,nu-cleartechn0logies,thecoolingofelectronicalcircuits,etc.Amongthemnaturalconvectioninsideanen-closedrectangularcavityisthemostclassicalproblem.Correspondinglyagreatdealofexperimentalandnumericalworkhasbeendoneinsuchafieldwiththe"clean"boundaryCPnditi0nsofuniformwalltem-perature(UWT)anduniformheatflch(UHF).Re-celltlymoreattelltionispaidontheconvectioninthecirculartube.HwangandLai[11inves…     

Experimental Investigations of the Three—Dimensional Flow in a Large Deflection Turbine Cascade with Tip Clearance

INTRoDUCTI0NThetipleakaeflowisnowrecognizedasanimpor-tantsourceoflossesinbothcompressorsandturbines,asasourceofcoolingprobleminturbinesandasourceofinstabilityincomPressorsandfans.Manyturbo-maChinimPellersarenotshroudedandtheleakaeflowthroughthetipgaPofthebladeisanunavoidablefaCtorwhichdeterioratestheperformance.Den-tonandCumpsty[1]melltionedabouttwodistinctandequallyimportantaspects.tothetipclearanceflows.First,thereisareducti0ninthebladeforce,there-fore,theworkdone.Thisoccursbecausethe…     

2001年1—12月份汽车生产销售情况表

20 0 1年 1～ 1 2月份汽车 (按车型分类 )生产企业生产销售情况表单位 :辆企业名称生产量销售量本月完成本期止累　计同期止累　计增长率(% )本月完成本期止累　计同期止累　计增长率(% )汽车企业总计 1937132 3344 4 0 2 0 6 94 2 312 .812 0 8930 2 36 36 6 5 2 0 86 34313.2     

二甲醚—空气—N2/CO2混合气燃烧特性研究

在定容燃烧弹中系统地研究了常温常压下,不同稀释气、不同稀释系数、不同燃空当量比时二甲醚-0空气-稀释气混合气的燃烧特性.基于容弹计算的准维双区模型和实测的燃烧压力数据,计算了燃烧温度及规范化质量燃烧速率.研究结果表明:随着稀释系数的增加,最大燃烧压力值、最高燃烧温度值以及规范化质量燃烧速率均降低,而火焰发展期和快速燃烧期随稀释系数的增加而增加.研究发现,CO2作为稀释气体时对燃烧温度降低的效果较N2作为稀释气体时更加明显.     

Effects of natural convection on the characteristics of a long laminar argon plasma jet issuing horizontally into ambient air

Three-dimensional modeling results show that the appearance of the long laminar plasma jet is less influenced by natural convection even as it is issuing into ambient air horizontally. However, plasma parameter distributions may deviate from axi-symmetry in the jet downstream region, especially for the cases with lower jet flow rates, and affect the applicability of Abel inversion employed in plasma diagnostics.     

Prediction of the entrainment of ambient air into a turbulent argon plasma jet using a turbulence-enhanced combined-diffusion-coefficient method

The entrainment of the ambient air into a turbulent argon plasma jet is studied numerically using a turbulence-enhanced combined-diffusion-coefficient method. Namely, the Navier-Stokes equations and two-equation turbulence model coupled with the turbulence-enhanced combined-diffusion-coefficient approach are employed to predict the turbulent plasma jet characteristics including the evolution of air mole fraction along the plasma jet in air surroundings. Although complicated gas species always exist in the plasma jet due to rather high gas temperatures being involved, it is shown that the entrainment of ambient air into the turbulent argon plasma jet can still be treated simply by the combined turbulent and molecular diffusion between only two different gases (argon and air). Good agreement between the predicted results with corresponding experimental data reported by Fincke et al. [Int. J. Heat Mass Transfer 46 (22) (2003) 4201] demonstrates the applicability of the present modeling approach.     

Effects of surrounding gas on the long laminar argon plasma jet characteristics

Comparative study is performed concerning the characteristics of long laminar argon plasma jets issuing into argon or into air surroundings. It is shown that when argon, instead of air, is used as the surrounding gas, besides pure argon atmosphere can be formed, the mass flow rate of surrounding gas entrained into the plasma jet and the length of jet high-temperature region increase but the gas specific enthalpy decreases in the downstream region of the plasma jet.     

Three-dimensional simulation of plasma spray: effects of carrier gas flow and particle injection on plasma jet and entrained particle behavior

As important phenomena in plasma spray, the plasma jet perturbation by the carrier gas flow and particles loading, and their effects on particle behavior are investigated. A three-dimensional computational model was developed to describe the plasma jet coupled with the orthogonal injection of carrier gas and particles. This model considered in-flight particle physical phenomena such as accelerating, heating, melting, and evaporation. The effects of carrier gas flow rates on the characteristics of plasma jet and particle spray pattern are simulated. The simulation results compare well with experimental data, for two common particle materials, NiCrAlY and ZrO₂.     

Fluid flow and heat transfer in plasma reactors—I. Calculation of velocities,temperature profiles and mixing

A mathematical representation has been developed to describe the velocity field and the associated temperature and concentration fields in a plasma jet system, which involves the injection of additional gas streams. In the statement of the problem, allowance was made for the swirl of the plasma jet, and one important objective of the work was to explore the effect of this swirl on the principal process variables. It was found that swirl plays an important role in providing mixing between the plasma jet and a reactant or diluent gas stream introduced through an annular port. It was shown, furthermore, that the model may be used for representing the quenching of the system by an axi-symmetrically introduced gas stream, having a direction perpendicular to the axis of the jet.     

3D modeling of evaporation of water injected into a plasma jet

3D effects of the radial injection of water jet into the swirl and non-swirl plasma jets are clarified numerically. The plasma-droplet two-way interactions are modeled by coupling Lagrangian approach for droplet behavior with an Eulerian approach for plasma flow under the dense loading. The effect of radial injection of the water jet on the temperature and flow fields of the swirl and non-swirl plasma jets is studied numerically. Mass concentration of the evaporated vapor is also predicted. The local deformation of the thermo-fluid fields of the plasma jet is stronger for higher droplet loading. Evaporation rate is decreased with increasing the droplet loading as well as swirl velocity. Mixing of vapor with plasma is stronger in the presence of swirl.     

直流双阳极等离子体特性的研究

利用高性能数字示波器、发射光谱法以及热力学方法,对直流双阳极等离子体发生器的伏安特性、射流的温度与射流的比焓特性进行了实验研究.结果表明,当等离子体的工作气体为纯氩气时,其弧压随电流的增加显著升高,且不随气体流量的增加而单调地变化;当工作气体为氩氮混合气体时,弧压随氮气的比例增加而急剧增大;氩等离子体射流的比焓随着电流的增大而增大,随着氩气流量的增加而减少;在相近的条件下氩氮等离子体射流的比焓远大于纯氩等离子体射流的比焓;氩等离子体射流在出口处的温度超过10000 K.     

Three-dimensional modeling of heat transfer and fluid flow in laminar-plasma material re-melting processing

Modeling study is performed concerning the heat transfer and fluid flow for a laminar argon plasma jet impinging normally upon a flat workpiece exposed to the ambient air. The diffusion of the air into the plasma jet is handled by using the combined-diffusion-coefficient approach. The heat flux density and jet shear stress distributions at the workpiece surface obtained from the plasma jet modeling are then used to study the re-melting process of a carbon steel workpiece. Besides the heat conduction within the workpiece, the effects of the plasma-jet inlet parameters (temperature and velocity), workpiece moving speed, Marangoni convection, natural convection etc. on the re-melting process are considered. The modeling results demonstrate that the shapes and sizes of the molten pool in the workpiece are influenced appreciably by the plasma-jet inlet parameters, workpiece moving speed and Marangoni convection. The jet shear stress manifests its effect at higher plasma-jet inlet velocities, while the natural convection effect can be ignored. The modeling results of the molten pool sizes agree reasonably with available experimental data.     

高热流密度量热探针的设计与实验

以热等离子体射流冲击平板传热的热流密度测量为背景,分析比较了文献中报道过的各种测量高热流密度的量热探针的结构及实验方法;结合特定实验条件,设计了新型量热探针并对其测量高热流密度的方法误差进行了分析,描述了实际测量采用的方法,给出若干初步实验结果。     

Melting of powder grains in a plasma flameFusion des grains spheriques dans un jet de plasmaSchmelzen von pulver-körnern in einer plasma-flammeПлa;влe;ниe; зio;p;e;н пo;p;o;шкa; в плa;змe;ннo;м фa;кe;лe;

A numerical method to determine the heat transfer and phase change processes of a spherical particle in a jet stream is deduced. The variations of the thermophysical properties of the particle and of the plasma with temperature are taken into account. An example of alumina particles heated in an argon-hydrogen plasma jet is given. The numerical results, compared with experimental measurements of surface temperature, particle velocity and diameter show good agreement.