专业英语题库1

选择题：1.If the system does not exchange energy with surroundings, it is an _________A open systemB closed systemC isolated systemD ontrol volume2. If the temperature of the liguid is lower than the saturation emperature for the existingpressure,it is called a_________liquid.A superheatedB subcooledC saturationD dry saturated3. If the efficiency of a real engine is significantly_______ the efficiency of a Carnotengine between the same limits, thenadditional improvements may be possible.A lower thanB more thanC equal toD greater than4. The velocity bector of a flow is expressed as V =ax2i+byztj, such a flow is a ____dimensional flow.A oneB twoC threeD four5. the critical Reynolds number of a rough-walled pipe is about_______.A 3x106B 3x105C 2000D 15006. If _______，the density variations influence the flow and compressibility effects shuldbe accounted for;such flows are compressinle flows.A M>0.3B M<0.3C M>0.2D M>0.17. Any _______effects that may exist are confined to a thin layer,called a boundarylayer,that is attached to the boundary ,the velocity in a boundary laryer is alwayszero at a fixed wall.A shearB gravitationalC inertialD viscous8. The ratio of the heat transfer surface area of a heat exchanger to its volume is calledthe area densityβ.A heat exchanger with_______is classifiedas being compact.A β<700m2/m3Bβ>700m2/m3Cβ>500m2/m3Dβ>1000m2/m39. The type of heat exchanger that involves the alternate passage of the hot and clodfluid streams through the same flow area is the _______heat exchanger.A regenerativeB compact Cplate and frame Dshell-and -tube10. Not all the radiation leaving one surface will reach the other surface sinceelectromagnetic radiation travels in straight lines and some will be lost to thesurroundings,we introduce _______in net radiant exchange.A reflectivityB emissivityC view factorD transmissivity11. _______use heat to conver water into steam for a variety of applications.A TurbinesB BoilersC GeneratorsD Condensers12. The modern 660MW coal-fired boilers has some _______tons of pressure parts.A 600B 2000C 6000D 2000013. ______is burned in coal boilers to ignite the coal burners,to warm up the boiler andraise pressure before coal is adimitted.A CoalB GasC WaterD Oil14. The radiant superheater outlet temperature ______with an increasing boiler out-put.A declinesB increasesC remains unchangedD decreases.15. The economizer is a ______heat exchanger for recovering enery from the fluegas.A parallelflowB upstreamC downstreamD counterflow.16. The ______utilises the heat in the boiler flue gases to heat the combustion air andprovide hot air for drying coal.A economizerB air heaterC reheaterD air preheater.17. There are no boiler tubes in the ______furnace of CFB because the rapidly movingsolids cause excessive erosion.A toppingB lowerC upperD middle18. The job of the pulverizers is to ______the feed coal down to a suitable size.A grindB heatC crushD warm19. The ball-and tube mill is a ______cylinder,partly filled with small diameter balls .A decliningB verticalC screwyD horizontal20. The Universal Pressure boiler is designed to maintain a ______flow inside thefurance circuits to prevent furace tube overheating during all operating conditionsA maximalB minimumC middleyD generic21. The steam after expending through the ______condenses in the condenser at a lowpress.A turbineB heaterC boilerD HP cylinder22. Machines in which there is no change of static or pressure head of the fluid in therotor are known as ______machine.A reactionB impulseC combined impulse and reactionD multi-stage23. The ______of a turbo-machine stage is defined as the ratio of the static orpressure head change occurring in the rotor to the total change across the stage.A degree of reactionB pressureC efficiencyD enthalpy24. For a turbine cylinder, substantial flanges and _____are required to withstand thepressure forces at the horizontal joints.A couplingB pipeC boltingD flange warming syetem25. With _____governing, the inlet belt is divided into sections each controlled by a sper–ate valve opening in sequence,resulting in a more complicated casting.A throttleB nozzleC slide pressureD constant pressure26. _____rotors required very careful attention to shrink fit and location geometries toavoid problems in running and with fatigue cracking.A integralB MonoblocC built-upD drum27. _____construction has the advantage of smaller forging components at the expenseof high integrity welding.A integralB shrink-on discC sub-criticalD Welded28. _____means that the weight is evenly disposed around the axis of theshaft. .A Static balanceB Dynamic balanceC balanceD Unbalance29. If critical speed is below running speed,the shaft is regarded as _____A rigidB flexibleC semi-flexibleD super-critical30 As a_____stage uses approximately the same heat drop as four impulse stage, it is usedto provide a shorter and cheaper turbine ,although with some sacrifice in efficiency.A impulseB reaction Cvelocity-compounded D single单词及词组aiabaticbafflebladeboilerboundary layerCarnot cyclecompositioncompressibilitycondensationconductionconvenctiondiffusiondry saturated vaporemissivityequilibriumfriction lossinternal combustion engineisentropicisobaricisolated systemisometricisothermallaminarmanuscriptmoisturemoleculepathlinepumpqualityradiationRankine cycleReversibleSaturationsteadystreamlinesubcooled liquidsuperheated vaporsurroundingturbulentultrasonicvacuumviscousAnchor 支座，固定Atomized 雾化Blast 鼓风Blowdown 排污Axis 轴Circulating fluidized bed CFB循环流化床锅炉Compressor 压缩机、压气机Coordinated 坐标，定位Counterflow 逆流（换热器）Creep strength 蠕变强度Critical pressure 临界压力Deterioration 恶化Distortion 变形Distillate 馏出物Drainage 疏水Drum 汽包Economizer 省煤器Erosive 侵蚀的，腐蚀的Embrittlement 脆性，脆化Evaluate 评估，评价Ferrite 铁素体Furnace 炉膛Generator 发电机Govern 控制、调节Hydraulic 水力的，液压的Ignite 点火Inert 惰性Ingredients 成分Inorganic 无机的Limestone 石灰石Margin 裕量，安全系数Mill 磨煤机Organisms 有机体Heterogeneous 不均匀的Hydraulic 水力的，液压的Ignite 点火Plasma spray coating 等离子喷涂Impurity 杂质Prefabricated 预制的Inert 惰性Inferior 低级的，劣质的Ingredients 成分Premium fuel 优质燃料Oxidation 氧化Polymer 聚合物Porosity多空的Radius 半径，范围Retract缩回Resonant 共振Reynolds number 雷诺数Rare earth element 稀土元素Regulate 控制，调节Rigid 刚性的，紧密地Rollers 辊子Regenerator 回热器，蓄热器Sootblower 吹灰器Saturated 饱和的Stress corrosion 应力腐蚀Superheater 过热器Temperature-entropy 温熵图Tenacious 黏的Thermodynamics 热力学Turbine 汽轮机Viscosity 黏度Velocity 速度Wear磨损Welded 焊接AccessAssemblyBack pressBalance pistonBearing boxBlowerBoundary layerBrittle fractureCarrier ringCasingCastChordConvergent-divergent type nozzle CouplingCoverbandCraneDouble-shell casingDuctilityDynamic balanceFabricationFatigue crackingFixed bladeFlexible rotorForgingFractureFull admissionHeadImpulseImpulse turbineInner casingKeyLacing wireMach numberMakeupMonobloc rotorMoving bladeNozzle boxNozzle governingOffsetPenetrationsPenultimate stageReaction machineResonanceRigid rotorRivetRobustRuptureStatic balanceThrottle governingToughnessWakeWheelTwisted三.翻译Thermodynamics is a science in which the storage,transfer of energy are studied.Energy is stored as internal energy,kinetic energy,potential energy and chemical energy; it is transformed from one of these forms to another;and it is transferred across a boundary as either heat or work.If a substance exists as vapor at the temperature,it is called saturated vapor.when the vapor is at a temperature greater than the saturation temperature,it is said to exist as superheated vapor.The pressure and temperature of superheated vapor are independent properties,since the temperature may increase while the pressure remainea constant.The first law of thermodynamics is commonly called the law of conservation of energy.In elementary physics course ,the study of conservation of energy emphasizes changes in kinetic and potentical energy and their relationship to work.A more general form of conservation of energy includes the effects of heat transfer and internal energy changes.Other forms of energy could also be included,such as electrostatic, magnetic,strain,and surface energy.Steam discharged from the turbine is directed into a condenser for two reasons.The condenser is operated at a high vacuum in order to create a low turbine exhaust pressure,rangingdown to 12mercury,abs.Turbines are ordinarily equipped with surface condensers that are indirect or nonmixing –type heat exchangers.In the abence of mixing,the second function of the condenser can be realized,that is ,the reture of the condenate to the boiler.beacause of the high steam flow,the condensate must be conserved,otherwise the operation of a large power boiler would be impracticable.A fluid flow may be broadly classified as either a viscous flow or an inviscid flow.An inviscid flow is one in which viscous effects of viscosity are important and cannot be ignored.To model an inviscid flow analytically,we can simply let the viscosity be zero;this will obviously make all viscous effects zero. It is more difficult to create an inviscid floe experimentally ,because all fluids of interest have viscosity.The questionthen becomes:Are there flows of interest in which the viscous effects are negligibly small? The answer is “Yes,if the shear stresses in the flow are small and act over such small areas that they do not significantly affect the flow field.”This statement is very general,of course, and it will take considerable analysis to justify the inviscid flow assumption.A viscous flow can be classified as either a laminar flow or a turbulent flow .In a laminar floe the fluid flows with no significant mixing of neighboring fluid particles. If dye were injected into the flow,it would not mix with the neighboring fluid exept by molecular activity; it would retain its identity for a relatively long period of time .Viscous shear stresses always influence alaminar flow . The floe may be highly time dependent or be steady.Incompressible gas flows include atmospheri flows, the aerodynamis of landing and takeoff of ommercial aircraft,heating and air-conditioning airflows, flow around automobiles and through radiators, and the flow of air around building, to name a few compressible flows include the aerodynamics of high-speed aircraft, airflow through jet engines, steam flow through the turbine in apower plant,airflow in a compressor, and the flow of the airgas mixture in an internal combustion engine.When a temperature gradient in a body,experience has shown that there is an energy transfer from the high-temperature region to the low –temperature region.We say that the energy is transferred by conduction and that the heat-transfer rate per unit area is proportional to the normal temperature gradient.热力学是一门科学,存储,传输的能量进行了研究。