热能与动力工程专业英语译文-第二章译文
热能与动力工程专业英语
Chapter 1 Introduction to Thermal Science第一章热科学基础Acoustic flow meter 声波流量计Corrugated fin 波状散热片Adiabatic[]绝热的Cross product 矢量积Aerodynamics 空气动力学Denominator 分母Affiliation 联系Developed flow 充分发展流Airfoil 机翼，螺旋桨Diffusion 扩散Alternative 替代燃料Doppler effect 多普勒效应Anemometer 风速计Double-pipe heat exchanger 套管式换热器Angular speed 角速度Dry saturated vapor 干饱和蒸汽Area density 表面密度Electrode 电极Baffle 挡板Electrolyte 电解，电解液Bifurcation 分形Electrostatic 静电的Blackbody 黑体Emissivity 发射率Blade 浆叶，叶片Equilibrium 平衡Boiler 锅炉Fluid mechanics 流体力学Boundary layer 边界层Forced convection 强制对流Carnot Cycle 卡诺循环Free convection 自然对流Cartesian coordinates 笛卡尔坐标系Friction loss 摩擦损失Celsius Degree 摄氏度Glass ceramic 微晶玻璃，玻璃陶瓷Compact heat exchanger 紧凑式换热器Heat engine 热机Composition 成分，合成物Heat pump 热泵Compressed liquid 压缩液体Hydrofoil 水翼Compressibility 可压缩性，压缩率Hypersonic speed 高超音速Condensation 凝结Infinitesimal 无穷小的Condenser 冷凝器Inflating/deflating 充气/压缩Conduction 导热Internal combustion engine 内燃机Control volume 控制体Isentropic 等熵的Convection 对流Isobaric 等压的Coriolis-accelaration flowmeter 科氏加速流量计Isolated system 孤立体系的Isometric 等容的Rough-wall tube 粗糙管Isothermal 等温的Saturation 饱和Kinematic viscosity 运动黏度Shear stress 剪切力、切应力Laminar 层流Shell-and-tube heat exchanger管壳式换热器Manuscript 手稿，原稿Specific volume 比容Moisture 湿度，水分Steady 稳态的，定常的Molecule (化学)分子Stifling engine 斯特林机Molten polymer 熔融聚合物Strain rate 变形速度，应变率Muti-disciplinary 多学科的Streamline 流线Newtonian Fluid 牛顿流体Strut 支撑，支柱Nominal temperature gradient 法向Subcooled liquid过冷液体温度梯度Numerator （数学）分子Superheated vapor 过热蒸汽Parallel flow 平行流动，并流Surrounding 环境，外界Pathline迹线Thermal conductivity 热传导率Phase change 相变Thermal efficiency 热效率Plane flow 平面流，二元流Thermodynamics 热力学Torsional 扭力的，扭转的Plate and flame heat exchanger板式换热器Polymer solution 胶浆Trailing edge 机翼后缘、尾缘Proof 校样Transmitter 传送装置、发送器Propeller 螺旋桨，推进器Turbine meter 涡轮流量计Pump泵Turbulent 湍流的Qulity 干度Ultrosonic 超声波的Qusi-equilibrium 准平衡、准静态Uniform flow 均匀刘Radiation 辐射Vacuum 真空Rankin Cycle 朗肯循环View factor 角系数Regenerative heat exchangerViscous 黏性的蓄热/再生式换热器Reservoir 水库，蓄水池Cortex shedding 漩涡脱落Reversible 可逆的Water faucet 水龙头，水嘴Rotameter 转子流量计Bi Biot number 比澳数NPSH 汽蚀余量CFD 计算流体力学NTU 传热单元数CHF 临界热流量Nu 努谢尔特数COP 制冷系数PE 势能Eu 欧拉数Pr 普朗特数Fo 富立叶数Ra 瑞利数Fr 弗劳德数Re 雷诺数Gr 格拉晓夫数Sc 施密特数KE 动能St 斯坦顿数，斯特劳哈数LMTD对数平均温差We 韦伯数1.1Fundamental of Engineering Thermodynamics1.1工程热力学基础Thermodynamics is a science in which the storage, transformation and transfer of energy are studied. Energy is stored as internal energy (associated with temperature), kinetic energy (du to motion), potential energy (due to elevation) and chemical energy (due to chemical composition); it is transformed from one of these forms to another; and it is transferred across a boundary as either heat or work.热力学是一门研究能量储存、转换及传递的科学。
热能与动力工程,内燃机,专业英语,翻译,课件
2. Four-stage-engine Operation四行程发动机工作过程The action taking place in the engine cylinder can be divided into four stages, or strokes. ―Stroke‖refers to piston movement; as stroke occurs when the piston moves from one limiting position to the other. The upper limit of piston movement is called TDC （top dead center）. The lower limit of piston movement is called BDC (bottom dead center). A stroke is piston movement from TDC to BDC or from BDC to TDC. In other words, the piston completes a stroke each time it change its direction of motion.发动机气缸内的工作过程，可以分为四个阶段，或行程。
行程涉及活塞的运动；活塞从某一限定位臵到另一限定位臵的运动称为一行程。
活塞运动的上限称为TDC（上止点），下限称为BDC（下止点）。
一个行程就是活塞从上止点到下止点，或从下止点到上止点的运动。
换句话说，活塞每完成一个行程，就改变一次其运动的方向。
Where the entire cycle of events in the cylinder requires four strokes (or two crankshaft revolutions), the engine is called a four-stroke-cycle engine, or a four-cycle engine. The four piston strokes are intake, compression, power, and exhaust.发动机气缸中的全部工作过程分为四个行程的（或者曲轴旋转两周的），叫做四行程循环发动机，或四循环发动机。
热能与动力工程专业英语
rear wall后壁
impingement碰撞
oil burner guns 燃油燃烧器油枪
the tip 出口简短
be imparted to给予
rim边缘impinge撞击 侵犯
chamber室 房间
viscosity粘性 粘度
virtue功效 优点
emerge through产生于
circumferential圆周的
the square of 平方
drool口水 流下
necessitate需要 迫使
spinning oil 拉丝油 旋转的油
discharge 排放卸货
atmospheric大气的 气压的
atmospheric corrosion[化工] 大气腐蚀atmospheric condenser[制冷] 大气冷凝器
usual practice惯例 通常办法
simultaneously同时的
subatmospheric低于大气的
combination burner 混合式燃烧器
flame-failure device 火焰故障检测设备
purge 吹扫
erosion 冲蚀 腐蚀
pulverized coal 煤粉
bypass damper旁路挡板
desuperheat使过热蒸汽减温
desuperheater 减温器
longitudinal 经度的 纵向的
cast iron 铸铁
extended surface 扩展表面
recuperative 再生的
supercritical 超临界
firetube boiler 火管锅炉
热能与动力工程专业英语全文翻译 整理版
第一章热科学基础工程热力学基础热力学是一门研究能量储存、转换及传递的科学。
能量以内能（与温度有关）、动能（由物体运动引起）、势能（由高度引起）和化学能（与化学组成相关）的形式储存。
不同形式的能量可以相互转化，而且能量在边界上可以以热和功的形式进行传递。
在热力学中，我们将推导有关能量转化和传递与物性参数，如温度、压强及密度等关系间的方程。
因此，在热力学中，物质及其性质变得非常重要。
许多热力学方程都是建立在实验观察的基础之上，而且这些实验观察的结果已被整理成数学表达式或定律的形式。
其中，热力学第一定律和第二定律应用最为广泛。
热力系统和控制体热力系统是一包围在某一封闭边界内的具有固定质量的物质。
系统边界通常是比较明显的（如气缸内气体的固定边界）。
然而，系统边界也可以是假想的（如一定质量的流体流经泵时不断变形的边界）。
系统之外的所有物质和空间统称外界或环境。
热力学主要研究系统与外界或系统与系统之间的相互作用。
系统通过在边界上进行能量传递，从而与外界进行相互作用，但在边界上没有质量交换。
当系统与外界间没有能量交换时，这样的系统称为孤立系统。
在许多情况下，当我们只关心空间中有物质流进或流出的某个特定体积时，分析可以得到简化。
这样的特定体积称为控制体。
例如泵、透平、充气或放气的气球都是控制体的例子。
包含控制体的表面称为控制表面。
因此，对于具体的问题，我们必须确定是选取系统作为研究对象有利还是选取控制体作为研究对象有利。
如果边界上有质量交换，则选取控制体有利；反之，则应选取系统作为研究对象。
平衡、过程和循环对于某一参考系统，假设系统内各点温度完全相同。
当物质内部各点的特性参数均相同且不随时间变化时，则称系统处于热力学平衡状态。
当系统边界某部分的温度突然上升时，则系统内的温度将自发地重新分布，直至处处相同。
当系统从一个平衡状态转变为另一个平衡状态时，系统所经历的一系列由中间状态组成的变化历程称为过程。
若从一个状态到达另一个状态的过程中，始终无限小地偏离平衡态，则称该过程为准静态过程，可以把其中任一个中间状态看作为平衡状态。
热能与动力工程专业英语翻译
Through the application of thermodynamic principles, modern heat engines have been developed.We are facing the reality that fossil fuel reserves are diminishing and will be insufficient in the forseeable future.Consequently, to those who study thermodynamics, increasing efficiency in the use of fossil fuels and the development of alternate sources of thermal energy are the real challenges to technology for today and tomorrow.Thermodynamics is a branch of science which deals with energy, its conversion from one form to another, and the movement of energy from one location to another. Thermodynamics is involved with energy exchanges and the associated changes in the properties of the working fluid or substance.Although thermodynamics deals with systems in motion, it does not concern itself with the speed at which such processes or energy exchanges occur.Thermodynamics, like other physical sciences, is based on observation of nature. Engineering thermodynamics consists of several parts, such as basic laws, thermal properties of the working fluids, process and cycle and so on.Energy is a primitive (原始的）property. We postulate（假定）that it is something that all matter has.Kinetic energy and potential energy are two forms of mechanical energy.A change of the total energy is equal to the rate of work done on the system plus the heat transfer to the system.Enthalpy can be used either as an extensive property H or as an intensive property h.The two terms v2/2 and gz represents kinetic energy and potential energy respectively. Although the net heat supplied to a thermodynamic system is equal to the net work done by the system, the gross energy supplied to the system must be greater than the net work done by the system.Not all of the input heat is available for producing output work because some heat must always be rejected by the system.Related to the second law statements are the concepts of availability of energy, entropy, process reversibility and thermal efficiency.In all reversible processes there is no change in the availability of the energy evolved in the process.Due to this concept of availability of energy, the following statements can be made: Only a portion of heat energy may be converted into work.Entropy S is an abstract thermodynamic property of a substance that can be evaluated only by calculation.From the above expression one can find that the value of entropy of the system will increase when the heat is transferred into the system.Processes that return to their initial state are called cyclic processes.The Carnot cycle is most efficient cycle possible operating between two given temperature levels.In the ideal Rankine cycle the efficiency may be increased by the use of a reheater section. The process of reheating in general raises the average temperature at which heat is supplied to the cycle, thus raising the theoretical efficiency.After partial expansion the steam is withdrawn from the turbine and reheated at constant pressure. Then it is returned to the turbine for further expansion to the exhaust pressure. For the portion of the heat-addition process from the subcooled liquid to saturated liquid, the average temperature is much below the temperature of the vaporization and superheating process.From the viewpoint of the second law, the cycle efficiency is greatly reduced.If this relatively low-temperature heat-addition process could be raised, the efficiency of the cycle would more nearly approach that of the Carnot cycle.The refrigeration cycle is used to transfer energy (heat) from a cold chamber, which is at a temperature lower than its surroundings.The basic refrigeration cycle consists of a sequence of processes utilizing a working fluid, called the refrigerant, usually in continuous circulation within a closed system.The refrigerant receives energy in the evaporator (cold chamber) at a temperature below that of the surroundings, and then rejects this energy in the condenser (hot chamber) prior to returning to its initial state.In the absence of friction these mechanical energies are completely interchangeable; that is, one unit of potential energy can be ideally converted into one unit of kinetic energy, and vice versa.It represents energy modes on the microscopic level, such as energy associated with nuclear spin, molecular binding, magnetic-dipole moment, molecular translation, molecular rotation, molecular vibration, and so on.In a static fluid, there is no motion of one layer of fluid relative to an adjacent layer, so there are no viscous shear forces.A knowledge of fluid statics is necessary for the solution of many familiar problems, such as the determination of total water force on a dam, the calculation of pressure variation throughout the atmosphere.With no relative motion between fluid particles, there are no shear forces acting on the element, only normal forces (due to pressure) and the gravity force.In order to solve problems in fluid flow, it is often necessary to determine the variation of pressure with velocity from point to point throughout the flow field.As one knows, a streamline is a continuous line drawn in the direction of the velocity vector at each point in the flow.For one-dimensional flow, the flow properties of which do not vary in the direction normal to the streamline, the constant in the Bernoulli equation is the same for all streamlines. The term pv is called flow work (energy/mass), the term v2/2 is the kinetic energy per unit mass; and gz is the potential energy per unit mass.There are two basic types of flow, each possessing fundamentally different characteristics. The first type is called laminar flow, the second turbulent flow.The transverse movement of a particle of fluid from a faster-moving layer to aslower-moving layer will have the effect of increasing the velocity in the slower-moving layer.The inlet length required to attain fully developed flow is dependent on the type of flow.In an analysis of flow through a pipe, we are interested in the type of flow, whether laminar or turbulent, since the shear stress and resultant frictional forces acting on the fluid vary greatly for the two types.Another way of looking at the difference between laminar and turbulent flows is to consider what happens when a small disturbance is introduced into a flow.The thickness of the laminar sublayer depends on the degree of turbulence of the main stream—the more turbulent the flow, the thinner the sublayer.We know that when a fluid flows through a pipe, the layer of fluid at the wall has zero velocity; layers of fluid at progressively greater distances from the pipe surface have higher velocities, with the maximum velocity occurring at the pipe centerline.However, even though the velocity fluctuations are small, they have a great effect on the flow characteristics.Furthermore, with the large number of random particle fluctuations present in a turbulent flow, there is a tendency toward mixing of the fluid and a more uniform velocity profile. When smoke leaves a cigarette, it travels upward initially in a smooth, regular pattern; at a certain distance above the cigarette, however, the smoke breaks down into an irregular pattern.Even in turbulent pipe flow, with the great majority of the flow characterized by rough, irregular motions, there will always be a thin layer of smooth laminar flow near a wall, for the particle fluctuations die out near a boundary.When the central of core region of the flow disappears, the flow is termed fully developed viscous flow.The science of heat transfer is concerned with the analysis of the rate of heat transfer taking place in a system. Heat flow will take place whenever there is a temperature gradient.Heat conduction is the term applied to the mechanism of internal energy exchange from one body to another, or from one part of a body to another.Heat conduction is realized by the exchange of the kinetic energy of the molecules by direct contact or by the drift of free electrons in the case of heat conduction in metals.The Fourier law may be used to develop an equation describing the distribution of the temperature throughout a heat-conducting solid.The term “steady state conduction” was defined as the condition which prevails when the temperatures of fixed points within a heat-conducting body do not change with time.The term “one-dimensional” is applied to a heat conduction problem when only one space coordinate is required to describe the distribution of temperature within a heat-conducting body.The solution of heat conduction problems involves, in general, the writing of the general heat conduction equation in terms of the appropriate number of arbitrary constants and then the evaluating of these constants by use of the imposed boundary conditions.The electrical analogy may be used to solve more complex problems involving both series and parallel thermal resistances.When fluid flows over a solid body or inside a channel while temperatures of the fluid and the solid surface different, heat transfer between the fluid and the solid surface takes place as a consequence of the motion of fluid relative to the surface.The multiplicity of independent variables results from the fact that convection transfer is determined by the boundary layers that develops on the surface.The velocity boundary layer is defined as the thin layer near the wall in which one assumes that viscous effects are important.It should be emphasized that a thermal boundary layer can also be defined as the region between the surface and the point at which the fluid temperature has reached a certain percentage of the fluid temperature.The thermal boundary layer is generally not coincident with the velocity boundary layer, although it is certainly dependent on it.Numerous analytic expressions are available for the prediction of heat transfer coefficient in laminar tube flow.There are numerous important engineering applications in which heat transfer for flow over bodies such as a flat plate, a sphere, a circular tube, or a tube bundle are needed.The temperature variation within the fluid will generate a density gradient which, in a gravitational field, will give rise, in turn, to a convective motion as a result of buoyancy forces.The fluid motion set up as a result of the buoyancy force（浮力）is called free convection, or natural convection.The flow velocity in free convection is much smaller than that encountered in forced convection; therefore, heat transfer by free convection is much smaller than that by forced convection.According to the different condensing situation, condensation can be divided into filmwise condensation and dropwise condensation.The phenomenon of heat transfer in boiling is extremely complicated because of a large number of variables involved and very complex hydrodynamic developments occurring in the process.All bodies continuously emit energy because of their temperature, and the energy thus emitted is called thermal radiation.The radiation energy emitted by a body is transmitted in the space in the form of electromagnetic waves according to Maxwell’s classic electromagnetic wave theory or in the form of discrete photons according to Planck’s hypothesis(假说）.The emission or absorption of radiation energy by a body is a bulk process; that is, radiation originating from the interior of the body is emitted through the surface.Heat exchangers are devices that facilitate heat transfer between two or more fluids at different temperatures.The C.O.P. of a refrigerating machine is ratio of Refrigerating effect to Work input.The C.O.P. of a refrigerator, unlike the efficiency of a heat engine can be much larger than unity.The essential parts of a vapor compression system are Evaporator Compressorcondenser, and Expansion valve.There are three types of vapor compressor: reciprocating, rotary, centrifugal.A vapor absorption system uses heat (thermal) energy to produce refrigeration.In an absorption system, the commonly used working substance is a solution of refrigerant and solvent.The four important factors involved in a complete air conditioning installation are:(i) Temperature control, (ii) Humidity control , (iii) Air movement and circulation, (iv) Air filtering, cleaning and purification .Give some applications of refrigerationdomestic refrigerationcommercial refrigerationindustrial refrigerationManufacture and preservation of medicinesPreservation of blood and human tissuesProduction of rocket fuelsComputer functioningmarine and transportation refrigerationWhat is a vapor compression system?A typical Vapor Compression Refrigeration SystemComponentsEvaporator: Heat exchangers for refrigerant to absorb heat from refrigerated space Compressor: to raise the temperature and pressure of refrigerant by compression Condenser: Heat exchangers for refrigerant to reject heat to the environmentReceiver tank: a reservoir to store the liquid refrigerantExpansion valve: or Refrigerant flow control, to reduce refrigerant pressureCycle diagramsWhat is the working principle of a vapor absorption system?Absorption refrigeration cycleA vapor absorption system uses heat (thermal) energy to produce refrigeration.In an absorption system, the commonly used working substance is a solution of refrigerant and solvent, such as Ammonia/water and Water/lithium bromide.A absorption refrigeration system also contains an evaporator and condenser which operate in exactly same way as for vapor compressor cycle.There is a second circuit around which an absorbent or solvent fluid flows. The evaporated refrigerant vapor is absorbed into the solvent at low pressure, and there is a net surfeit of heat for this process.The solvent, now diluted by refrigerant is raised to the high pressure by a liquid pump. High pressure refrigerant vapor is then produced by the addition of heat to the mixture, in the generator.Nuclear energy results from changes in the nucleus of atoms.As a nucleus splits, it releases a tremendous amount of heat.The nucleus splitting process is completely fissioned, it will create as much heat as the burning of 1500 short tons of coal.In 1911 the physicist Ernest Rutherford first discovered the existence of a subatomic particle, later referred to as the nucleus.In 1938, two German chemists, Otto Hahn and Fritz Strassmann reported they had produced the element barium by bombarding(轰击) uranium with neutrons.This reaction had in fact split an uranium nucleus into two nearly equal fragments(碎片）, one of which was a barium（钡）nucleus and another was a krypton（氪）nucleus.Albert Einstein developed his famous relativity theory and related the matter to energy by the equation E=mc2.Cadmium（镉）rods were used to control the chain reaction.By 1960, nuclear power generating systems in the range of 150 to 200 MW were in commercial operation.Free neutron capture upsets the internal force, which holds together the tiny particles called protons and neutrons in the nucleus.Besides the heat energy produced, fission releases an average of two or three neutrons and such nuclear radiation as gamma rays.If one of the neutrons emitted is captured by another fissionable nucleus, a second fission takes place in the manner similar to the first.When the fission becomes self-sustaining, the process is called a chain reaction.Nuclear reactors used for electric power generation consist of four main parts.They are (1) the fuel core, (2) the moderator and coolant, (3) the control rods, and (4) the reactor vessel .The fuel core contains the nuclear fuel and is the part of the reactor in which the fission takes place.In fission process the fertile materials( for instance, the U-238 ) are converted to fissile. Fertile: 可变成裂变物质的The nuclear fuel is generally contained in cylindrical rods surrounded by cladding materials，such as aluminum(铝), magnesium(镁), zirconium(锌), stainless steel, and graphite(石墨). The moderator is the substance used in nuclear reactor to reduce the energy of fast neutrons to thermal neutrons.The reactor coolant is used to remove heat from the reactor fuel core, including light water, heavy water, air, carbon dioxide, helium, sodium(钠), potassium(钾), and some organic liquids.Control rods are long metal rods that contain such elements as boron硼, cadmium镉, or hafnium罕. These elements absorb fast neutrons and therefore help control a chain reaction.The reactor vessel is a tanklike structure that holds the reactor core and other internals.The two principal types are the PWR and BWR. Both reactors use enriched uranium and light water as coolant as well as moderator.The coolant first flows downward through the annular space between the shield wall and the core barrel into a plenum at the bottom of the vessel.Then the coolant reverses its direction and flows upward through the fuel core.The heated coolant is collected at the upper plenum and exits the vessel through outlet nozzles.A reactor coolant system is usually designed with two or more closed coolant loops connected to the PWR, each containing its own steam generator and coolant pump.The steam-water mixture from the tube bundle passes through a steam swirl旋转vane叶片assembly where steam is separated from the water.In addition to the steam generator, each coolant loop in the PWR has its own pump.An electrically heated pressurizer is connected to one of the coolant loops and is used to serve the whole coolant system.The pressurizer is used to maintain the coolant pressure during steady-state operation, and to limit the pressure changes, preventing the pressure from exceeding the design limit. Boiling water nuclear steam supply system mainly consists of reactor vessel and reactor coolant circuits.Unlike the PWR, BWR system does not have the intermediate heat exchanger, or steam generator, between the coolant loop and the feedwater and steam system.For a BWR plant, steam is generated within the nuclear reactor and transferred directly to the steam turbine.A disadvantage of the BWR system is that radioactive carry-over into the steam must be guarded against and special provisions made to reduce leakage at the shaft seals of the turbine.The plant, having a peak capacity of 12 kWe, has been intended as a demonstration and a pilot plant for electricity production from solar energy.The plant is composed of three main parts: a field of flat plate solar water collectors (primary circuit); a hot water storage tank (interface); and a turbo-generator group (secondary circuit).The operating mechanism of the plant is based on the principle of converting solar energy into thermal energy.The converted energy is then stored in the hot water storage tank until reaching a temperature level of 100°C (called the index temperature), which triggers the startup of the turbo-generator group operation.The primary circuit of the plant consists of 396 flat plate solar collectors covering a net aperture area of 760 m2.The converted solar energy into thermal energy is stored in a sensible heat form within a water storage tank.The geometry of the storage tank presents the advantage of favoring the forming of a thermal stratification within the storage.The turbo-generator group (TGG) consists of an evaporator, a turbine, a condenser and an alternator.The evaporator and the condenser are both heat exchangers made of copper tubes allowing the heat transfer between the fluid and both the hot and cold sources.The turbine is of a single stage type characterized by an axial flux having a rotation speed of 900 rpm.A parabolic concentrator unit is designed to increase the temperature at the bottom of the storage tank whenever the climatic conditions are favorable.。
热能与动力工程专业英语翻译 5.11(2)
热能与动力工程专业英语翻译2.5
2.5 Natural Convectionnatural or free convection.therefore important not to ignore radiation in calculating the total heat loss or gain.wall temperatures in a room can affect human comfort.（1）gravity coils used in high humidity cold storage rooms and in roof-mounted refrigerant condensers,(2)the evaporator and condenser of household refrigerators, (3) baseboard radiators and convectors for space heating and(4)cooling panels for airdifference in density of the adjacent fluid.diffusion.β, the kinematic viscosity ν (=μ/ρ) ,and the thermal diffusivity α=(κ/ρc p )., Nu, is a function of the product of the Prandtl number ，Pr ，and Grashof number ，Gr， which ，when combined ，depend on the fluid properties ，，Δt ，and the characteristic length of the surface ，L.divided into three regions: (1) turbulent natural convection for which n equals 0.33, (2) laminar natural convection, for which n equals 0.25 and (3) a region that has ( Gr·Pr) less than for laminar convection, for which the exponent n gradually diminishes from 0.25 to lower values.Pr) is likely to be very small, so that the exponent n is 0.1.Pr) to find whether the boundary layer is laminar or turbulent, then apply the appropriate equation.transfer coefficient is independent of the characteristic length., the heat transfer coefficient for vertical pipes islarger than for horizontal pipes.facing upward can be used.for natural convective heat transfer coefficients indicate that caution should be taken when applying coefficients for (isolated) vertical plates recommended by ASHRAE for situations with vertical surfaces in enclosed spaces (buildings).correlations for calculating natural convective heat transfer from vertical surfaces in rooms undercertain temperature boundary conditions have been developed.the forced convection effect, i.e. , the Reynolds number , increases, the“mixed convection”(superimposedcombined free and forced convection heat transfer .tubes.conditions influence the values of the convection coefficient in a mixed convection regime, but the references permit locating the pertinent regime and approximating the convection coefficient.。
大学热动专业英语1-2章翻译
Specialized English for Thermal Energy & Power EngineeringCOURSE OUTLINETextbook: 热能与动力工程专业英语（Specialized English for Thermal Energy & Power Engineering）(3th) 阎维平，中国电力出版社（第三版）COURSE OUTLINECourse Goals:1.To understand the basic characteristics of Specialized English.2.To recognize some technical words in thermal energy and power engineering.3.To know how to write the abstract for a paper or a thesis (P155).Grading:Exercises in the class 20%Final exam 80%ContentsChapter 1 Introduction to Thermal Sciences1.1 Fundamental of engineering thermodynamics1.2 Fundamental of fluid mechanics1.3 Fundamental of heat transferChapter 2 Boiler2.1 Introduction2.2 Development of utility boiler2.3 Fuel and combustion2.4 Pulverizing system2.5 System arrangement and key components2.6 On-load cleaning of boilers2.7 Energy balanceChapter 1 Introduction to Thermal Sciences1.1 Fundamental of engineering thermodynamics•Thermodynamics is a science in which the storage, transformation, and transfer of energy are studied. Energy is stored as internal energy( associated with temperature), kinetic energy( due to motion), potential energy (due to elevation) and chemical energy( due tochemical composition); it is transformed from one of these forms to another; and it is transferred across a boundary as either heat or work.第一章热科学介绍1.1 工程热力学基础热力学是一门研究能量储存、转换及传递的科学。
热能与动力工程专业英语全文翻译 最新整理版
第一章热科学基础工程热力学基础热力学是一门研究能量储存、转换及传递的科学。
能量以内能（与温度有关）、动能（由物体运动引起）、势能（由高度引起）和化学能（与化学组成相关）的形式储存。
不同形式的能量可以相互转化，而且能量在边界上可以以热和功的形式进行传递。
在热力学中，我们将推导有关能量转化和传递与物性参数，如温度、压强及密度等关系间的方程。
因此，在热力学中，物质及其性质变得非常重要。
许多热力学方程都是建立在实验观察的基础之上，而且这些实验观察的结果已被整理成数学表达式或定律的形式。
其中，热力学第一定律和第二定律应用最为广泛。
热力系统和控制体热力系统是一包围在某一封闭边界内的具有固定质量的物质。
系统边界通常是比较明显的（如气缸内气体的固定边界）。
然而，系统边界也可以是假想的（如一定质量的流体流经泵时不断变形的边界）。
系统之外的所有物质和空间统称外界或环境。
热力学主要研究系统与外界或系统与系统之间的相互作用。
系统通过在边界上进行能量传递，从而与外界进行相互作用，但在边界上没有质量交换。
当系统与外界间没有能量交换时，这样的系统称为孤立系统。
在许多情况下，当我们只关心空间中有物质流进或流出的某个特定体积时，分析可以得到简化。
这样的特定体积称为控制体。
例如泵、透平、充气或放气的气球都是控制体的例子。
包含控制体的表面称为控制表面。
因此，对于具体的问题，我们必须确定是选取系统作为研究对象有利还是选取控制体作为研究对象有利。
如果边界上有质量交换，则选取控制体有利；反之，则应选取系统作为研究对象。
平衡、过程和循环对于某一参考系统，假设系统内各点温度完全相同。
当物质内部各点的特性参数均相同且不随时间变化时，则称系统处于热力学平衡状态。
当系统边界某部分的温度突然上升时，则系统内的温度将自发地重新分布，直至处处相同。
当系统从一个平衡状态转变为另一个平衡状态时，系统所经历的一系列由中间状态组成的变化历程称为过程。
若从一个状态到达另一个状态的过程中，始终无限小地偏离平衡态，则称该过程为准静态过程，可以把其中任一个中间状态看作为平衡状态。
热能与动力工程专业英语
Chapter 1 Introduction to Thermal Science第一章热科学基础Acoustic flow meter 声波流量计Corrugated fin 波状散热片Adiabatic []绝热的Cross product 矢量积Aerodynamics 空气动力学Denominator 分母Affiliation 联系Developed flow 充分发展流Airfoil 机翼，螺旋桨Diffusion 扩散Alternative 替代燃料Doppler effect 多普勒效应Anemometer 风速计Double-pipe heat exchanger 套管式换热器Angular speed 角速度Dry saturated vapor 干饱和蒸汽Area density 表面密度Electrode 电极Baffle 挡板Electrolyte 电解，电解液Bifurcation 分形Electrostatic 静电的Blackbody 黑体Emissivity 发射率Blade 浆叶，叶片Equilibrium 平衡Boiler 锅炉Fluid mechanics 流体力学Boundary layer 边界层Forced convection 强制对流Carnot Cycle 卡诺循环Free convection 自然对流Cartesian coordinates 笛卡尔坐标系Friction loss 摩擦损失Celsius Degree 摄氏度Glass ceramic 微晶玻璃，玻璃陶瓷Heat engine 热机Compact heat exchanger 紧凑式换热器Composition 成分，合成物Heat pump 热泵Compressed liquid 压缩液体Hydrofoil 水翼Compressibility 可压缩性，压缩率Hypersonic speed 高超音速Condensation 凝结Infinitesimal 无穷小的Condenser 冷凝器Inflating/deflating 充气/压缩Conduction 导热Internal combustion engine 内燃机Control volume 控制体Isentropic 等熵的Convection 对流Isobaric 等压的Coriolis-accelaration flowmeter 科Isolated system 孤立体系的氏加速流量计Isometric 等容的Rough-wall tube 粗糙管Isothermal 等温的Saturation 饱和Kinematic viscosity 运动黏度Shear stress 剪切力、切应力Laminar 层流Shell-and-tube heat exchanger管壳式换热器Manuscript 手稿，原稿Specific volume 比容Moisture 湿度，水分Steady 稳态的，定常的Molecule (化学)分子Stifling engine 斯特林机Molten polymer 熔融聚合物Strain rate 变形速度，应变率Muti-disciplinary 多学科的Streamline 流线Newtonian Fluid 牛顿流体Strut 支撑，支柱Nominal temperature gradient 法向Subcooled liquid过冷液体温度梯度Numerator （数学）分子Superheated vapor 过热蒸汽Parallel flow 平行流动，并流Surrounding 环境，外界Pathline迹线Thermal conductivity 热传导率Phase change 相变Thermal efficiency 热效率Plane flow 平面流，二元流Thermodynamics 热力学Torsional 扭力的，扭转的Plate and flame heat exchanger板式换热器Polymer solution 胶浆Trailing edge 机翼后缘、尾缘Proof 校样Transmitter 传送装置、发送器Propeller 螺旋桨，推进器Turbine meter 涡轮流量计Pump泵Turbulent 湍流的Qulity 干度Ultrosonic 超声波的Qusi-equilibrium 准平衡、准静态Uniform flow 均匀刘Radiation 辐射Vacuum 真空Rankin Cycle 朗肯循环View factor 角系数Regenerative heat exchangerViscous 黏性的蓄热/再生式换热器Reservoir 水库，蓄水池Cortex shedding 漩涡脱落Reversible 可逆的Water faucet 水龙头，水嘴Rotameter 转子流量计Bi Biot number 比澳数NPSH 汽蚀余量CFD 计算流体力学NTU 传热单元数CHF 临界热流量Nu 努谢尔特数COP 制冷系数PE 势能Eu 欧拉数Pr 普朗特数Fo 富立叶数Ra 瑞利数Fr 弗劳德数Re 雷诺数Gr 格拉晓夫数Sc 施密特数KE 动能St 斯坦顿数，斯特劳哈数LMTD对数平均温差We 韦伯数1.1Fundamental of Engineering Thermodynamics1.1工程热力学基础Thermodynamics is a science in which the storage, transformation and transfer of energy are studied. Energy is stored as internal energy (associated with temperature), kinetic energy (du to motion), potential energy (due to elevation) and chemical energy (due to chemical composition); it is transformed from one of these forms to another; and it is transferred across a boundary as either heat or work.热力学是一门研究能量储存、转换及传递的科学。
热动专业英语翻译第2章
热能与动力工程教研室
Department of Thermal Energy & Power Engineering
Specialized English for Thermal Energy & Power Engineering
Utility boilers are used primarily to generate electricity in large central power stations. They are designed to optimise overall thermodynamic efficiency at the highest possible availability. A key characteristic of newer units is the use of a reheater section to increase overall cycle efficiency.
整体煤气化联合循环（IGCC）：在CC基础上增加煤气化 以降低燃料费用并将污染排放降到最低。 增压循环流化床燃烧（PFBC）：在更高压力下燃烧，包 括燃气净化，以及燃烧产物膨胀并通过燃气轮机做功。 高炉排烟热量回收：利用高炉余热产生蒸汽。 太阳能蒸汽发生器：利用集热器收集太阳辐射热产生蒸汽。
热能与动力工程教研室
热能与动力工程教研室
Department of Thermal Energy & Power Engineering
Specialized English for Thermal Energy & Power Engineering
现代蒸汽发生系统可根据不同的标准分类。这 些包括最终用途、燃烧方式、运行压力、燃料和循 环方式。大型中心电站的电站锅炉主要用来发电。 经过优化设计，使最大可能可用性时有最高的热效 率。新机组的关键特性是利用再热器提高整个循环 效率。
热能与动力工程专业英语全文翻译 最新整理版
第一章热科学基础工程热力学基础热力学是一门研究能量储存、转换及传递的科学。
能量以内能（与温度有关）、动能（由物体运动引起）、势能（由高度引起）和化学能（与化学组成相关）的形式储存。
不同形式的能量可以相互转化，而且能量在边界上可以以热和功的形式进行传递。
在热力学中，我们将推导有关能量转化和传递与物性参数，如温度、压强及密度等关系间的方程。
因此，在热力学中，物质及其性质变得非常重要。
许多热力学方程都是建立在实验观察的基础之上，而且这些实验观察的结果已被整理成数学表达式或定律的形式。
其中，热力学第一定律和第二定律应用最为广泛。
热力系统和控制体热力系统是一包围在某一封闭边界内的具有固定质量的物质。
系统边界通常是比较明显的（如气缸内气体的固定边界）。
然而，系统边界也可以是假想的（如一定质量的流体流经泵时不断变形的边界）。
系统之外的所有物质和空间统称外界或环境。
热力学主要研究系统与外界或系统与系统之间的相互作用。
系统通过在边界上进行能量传递，从而与外界进行相互作用，但在边界上没有质量交换。
当系统与外界间没有能量交换时，这样的系统称为孤立系统。
在许多情况下，当我们只关心空间中有物质流进或流出的某个特定体积时，分析可以得到简化。
这样的特定体积称为控制体。
例如泵、透平、充气或放气的气球都是控制体的例子。
包含控制体的表面称为控制表面。
因此，对于具体的问题，我们必须确定是选取系统作为研究对象有利还是选取控制体作为研究对象有利。
如果边界上有质量交换，则选取控制体有利；反之，则应选取系统作为研究对象。
平衡、过程和循环对于某一参考系统，假设系统内各点温度完全相同。
当物质内部各点的特性参数均相同且不随时间变化时，则称系统处于热力学平衡状态。
当系统边界某部分的温度突然上升时，则系统内的温度将自发地重新分布，直至处处相同。
当系统从一个平衡状态转变为另一个平衡状态时，系统所经历的一系列由中间状态组成的变化历程称为过程。
若从一个状态到达另一个状态的过程中，始终无限小地偏离平衡态，则称该过程为准静态过程，可以把其中任一个中间状态看作为平衡状态。
热能与动力工程专业英语
Chapter 1 Introduction to Thermal Science第一章热科学基础Acoustic flow meter 声波流量计Corrugated fin 波状散热片Adiabatic[]绝热的Cross product 矢量积Aerodynamics 空气动力学Denominator 分母Affiliation 联系Developed flow 充分发展流Airfoil 机翼，螺旋桨Diffusion 扩散Alternative 替代燃料Doppler effect 多普勒效应Anemometer 风速计Double-pipe heat exchanger 套管式换热器Angular speed 角速度Dry saturated vapor 干饱和蒸汽Area density 表面密度Electrode 电极Baffle 挡板Electrolyte 电解，电解液Bifurcation 分形Electrostatic 静电的Blackbody 黑体Emissivity 发射率Blade 浆叶，叶片Equilibrium 平衡Boiler 锅炉Fluid mechanics 流体力学Boundary layer 边界层Forced convection 强制对流Carnot Cycle 卡诺循环Free convection 自然对流Cartesian coordinates 笛卡尔坐标系Friction loss 摩擦损失Celsius Degree 摄氏度Glass ceramic 微晶玻璃，玻璃陶瓷Compact heat exchanger 紧凑式换热器Heat engine 热机Composition 成分，合成物Heat pump 热泵Compressed liquid 压缩液体Hydrofoil 水翼Compressibility 可压缩性，压缩率Hypersonic speed 高超音速Condensation 凝结Infinitesimal 无穷小的Condenser 冷凝器Inflating/deflating 充气/压缩Conduction 导热Internal combustion engine 内燃机Control volume 控制体Isentropic 等熵的Convection 对流Isobaric 等压的Coriolis-accelaration flowmeter 科Isolated system 孤立体系的氏加速流量计Isometric 等容的Rough-wall tube 粗糙管Isothermal 等温的Saturation 饱和Kinematic viscosity 运动黏度Shear stress 剪切力、切应力Laminar 层流Shell-and-tube heat exchanger管壳式换热器Manuscript 手稿，原稿Specific volume 比容Moisture 湿度，水分Steady 稳态的，定常的Molecule (化学)分子Stifling engine 斯特林机Molten polymer 熔融聚合物Strain rate 变形速度，应变率Muti-disciplinary 多学科的Streamline 流线Newtonian Fluid 牛顿流体Strut 支撑，支柱Nominal temperature gradient 法向Subcooled liquid过冷液体温度梯度Numerator （数学）分子Superheated vapor 过热蒸汽Parallel flow 平行流动，并流Surrounding 环境，外界Pathline迹线Thermal conductivity 热传导率Phase change 相变Thermal efficiency 热效率Plane flow 平面流，二元流Thermodynamics 热力学Torsional 扭力的，扭转的Plate and flame heat exchanger板式换热器Polymer solution 胶浆Trailing edge 机翼后缘、尾缘Proof 校样Transmitter 传送装置、发送器Propeller 螺旋桨，推进器Turbine meter 涡轮流量计Pump泵Turbulent 湍流的Qulity 干度Ultrosonic 超声波的Qusi-equilibrium 准平衡、准静态Uniform flow 均匀刘Radiation 辐射Vacuum 真空Rankin Cycle 朗肯循环View factor 角系数Viscous 黏性的Regenerative heat exchanger蓄热/再生式换热器Reservoir 水库，蓄水池Cortex shedding 漩涡脱落Reversible 可逆的Water faucet 水龙头，水嘴Rotameter 转子流量计Bi Biot number 比澳数NPSH 汽蚀余量CFD 计算流体力学NTU 传热单元数CHF 临界热流量Nu 努谢尔特数COP 制冷系数PE 势能Eu 欧拉数Pr 普朗特数Fo 富立叶数Ra 瑞利数Fr 弗劳德数Re 雷诺数Gr 格拉晓夫数Sc 施密特数KE 动能St 斯坦顿数，斯特劳哈数LMTD对数平均温差We 韦伯数1.1Fundamental of Engineering Thermodynamics1.1工程热力学基础Thermodynamics is a science in which the storage, transformation and transfer of energy are studied. Energy is stored as internal energy (associated with temperature), kinetic energy (du to motion), potential energy (due to elevation) and chemical energy (due to chemical composition); it is transformed from one of these forms to another; and it is transferred across a boundary as either heat or work.热力学是一门研究能量储存、转换及传递的科学。
热能与动力工程专业英语-翻译（李瑞扬）
热能与动力工程专业英语-翻译（李瑞扬）1.3 The Characteristics of Fluids 流体的特征constituent：组成的；tangential：切向的；restrain：限制、约束；equilibrium：平衡，均衡；interface：相互关系、分界面；molecule：微小颗粒、分子；continuum：连续体；vessel：容器；tar：焦油、柏油；pitch：树脂；imperceptibly：察觉不到的，细微的；restore：恢复；subside：下沉、沉淀、减退、衰减；hypothetically：假设地、假想地；sphere：球、球体；microvolume：微元体积；rarest：最稀罕的，虽珍贵的A fluid is a substance which may flow; that is, its constituent particles may continuously change their positions relative to one another. Moreover, it offers no lasting resistance to the displacement, however great, of one layer over another. This means that, if the fluid is at rest, no shear force (that is a force tangential to the surface on which it acts )can exist in it. A solid, on the other hand, can resist a shear force while at rest; the shear force may cause some displacement of one layer over another, but the material does not continue to move indefinitely. In a fluid, however, shear forces are possible only while relative movement between layers is actually taking place. A fluid is further distinguished from a solid in that a given amount of it owes its shape at any particular time to that of a vessel containing it, orto forces which in some way restrain its movement. 流体是可以流动的物质，也就是说，组成流体的质点可以连续的改变它们的相对位置。
热能与动力工程专业英语翻译Ch 02 教案
Chapter 2 Boiler第二章锅炉Air heater 空预器Commissioning 试运行Anchor 支座，固定Compressor 压缩机、压气机Anhydrous ammonia 无水氨Condenser 凝汽器Anthracite 无烟煤Containment 反应堆安全壳Atomized 雾化Convection 对流Austenitic 奥氏体钢Coolant 制冷剂Auxialiary 辅助机械Coordinated 坐标，定位Axis 轴Corten低合金耐腐蚀钢Bagasse 甘蔗渣Counterflow 逆流（换热器）Bare tube 光管Creep strength 蠕变强度Bark 树皮Criterion 标准Beam 梁，横梁Critical pressure 临界压力Bituminous coal 烟煤Culm 煤屑Blade 叶片Cyclone furnace 旋风炉Blast 鼓风Debris 残骸、有机残留物Blowdown 排污Decane 癸烷Boiler 锅炉Decay 分解Bulk 大块的Deposited 沉积，沉淀的Burner zone 燃烧器区域Deterioration 恶化Butane 丁烷Diesel oil 柴油Calcination 煅烧Differential 差动，微分Capacity 出力Distillate 馏出物Carbon steel 碳钢Distortion 变形Cerium 铈Division wall 分隔墙，双面水冷壁Chromium 铬Drainage 疏水Drum 汽包Circulating fluidized bed CFB 循环流化床锅炉Coal char 煤焦Dwell time 保留时间Cogenerator 热点联产机组Economizer 省煤器Combustion 燃烧Embrittlement 脆性，脆化Equalization 均衡，平衡Ingress进口，入口Erosive 侵蚀的，腐蚀的In-line 顺列Ethane 乙烷Inorganic 无机的Evaluate 评估，评价Ion 离子Evaporate 蒸发Jurisdiction 权限Excess air 过量空气Lignite 褐煤Extended surface 扩展受热面Lime 石灰Fatigue 疲劳Limestone 石灰石Feedwater 给谁Low alloy 低合金钢Ferrite 铁素体Low-volatile 低挥发分的Fin 鳍片，肋片Margin 裕量，安全系数Flange 法兰Matrix 矩阵Flue gas 烟气Membrane 膜Fouling 沾污Methane 甲烷Furnace 炉膛Mill 磨煤机Generator 发电机Molecule 分子Geological 地质的Molten 熔化Girth 环形Nitric oxide 氮氧化物Govern 控制、调节Nonpressure 非承压的Gravity 重力Nontoxic 无毒的Header 联箱，集箱Organisms 有机体Helical 螺旋状的Oxidation 氧化Helium 氦Peat 泥煤Heterogeneous 不均匀的Pendants superheat platen悬吊式屏式过热器Hopper 斗，料斗Pentane 戊烷Husk 壳，外壳Petrochemical 石油化工制品Hydraulic 水力的，液压的Petroleum 石油制品Ignite 点火Plasma spray coating 等离子喷涂Impurity 杂质Platen 屏Inert 惰性Polymer 聚合物Inferior 低级的，劣质的Pores 气孔，小孔Ingredients 成分Porosity多空的Potassium 钾Slurry 水煤浆Prandtl numbers 普朗特数Sodium 钠Prefabricated 预制的Solvents 溶剂Premium fuel 优质燃料Sootblower 吹灰器Pressure loss 压力损失Sour gas 含硫气体Primary air 一次风Specification 规格Propane 丙烷Stable ignition 稳定着火Proximate analysis 工业分析Stanton number 斯坦顿数Pulp 纸浆Saturated 饱和的Pyrites 黄铁矿Straw 稻草Radius 半径，范围Steam line blowing 蒸汽管路吹灰Rare earth element 稀土元素Steams 茎，杆Recuperator 间壁式换热器Stress corrosion 应力腐蚀Regenerator 回热器，蓄热器Structural formula 结构式Regulate 控制，调节Stud 双头螺栓Repercussions 反应Subbituminous 贫煤，次烟煤Reservoirs 储气罐Suction 真空，负压Residuale fuel oil 渣油Sulphur 硫Resonant 共振Superheater 过热器Retract缩回Swamp 沼泽Reynolds number 雷诺数Sweet gas 无硫气Rigid 刚性的，紧密地Switchgear 配电装置，开关装置Rollers 辊子Temperature-entropy 温熵图Scale 水垢，Tenacious 黏的Seal 密封Thermodynamics 热力学Sedimentary 沉积Tube bundles 管束Serpentine tube 蛇形管Tubular 管状的Shale 页岩Turbine 汽轮机Silica 二氧化硅Velocity 速度Silt 淤泥Vertical spidle mill 中速磨，立轴磨Single-phase 单相Vessel 容器Skin casing 外护板Viscosity 黏度Slag 结渣V olumetric expansion 体膨胀Vulnerable 易损的，薄弱的DEH 数字电液系统Wear磨损DNB 偏离核态沸腾Welded 焊接FDF 送风机Wingwall屏式凝渣管FGD 烟气脱硫Yttrim 釔FSSS 炉膛安全检测保护系统Abbreviations HRB 回热锅炉AFBC 常压流化床燃烧IDF 引风机AFCO 燃料自动切断IGCC 整体煤气化联合循环AFWC 给水自动切断LMTD 对数平均温差ASME 美国机械工程师协会MFT 主燃料切断ATM 标准大气压MUF 锅炉补给水BFP 锅炉给水泵NWL 正常水位BUT 按钮OFA 火上风，燃尽风BWC锅炉水浓度PFBC 增压流化床燃烧BYP 旁路SSC 刮板除渣机CFBB 循环流化床锅炉TGA 热重分析仪MCR 最大连续蒸发量UBC 未燃烧DAS 数据采集系统WFGD 湿法烟气脱硫2.1 IntroductionBoilers use heat to convert water into steam for a variety of applications. Primary among these are electric power generation and industrial process heating. Steam has become a key resource because of its wide availability, advantageous properties and non toxic nature. The steam flow rates and operating conditions can vary dramatically; from 1000lb/h (0.1kg/s) in one process use to more than 10 million lb/h (1260kg/s) in large electric power plant; from about 14.7 psi (1 bar) and 212ºF in some heating applications to more than 4500 psi (310bar) and 1100ºF (593℃) in advanced cycle power plant.2.1 简介SSC锅炉利用热量使水转变成蒸汽以进行各种利用。
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第二章锅炉2.1 简介SSC锅炉利用热量使水转变成蒸汽以进行各种利用。
其中主要是发电和工业供热。
由于蒸汽具有有利的参数和无毒特性，因此蒸汽作为一种关键的工质（资源）被广泛地应用。
蒸汽流量和运行参数的变化很大：从某一过程里1000磅/小时（0.126kg/s）到大型电厂超过10×106磅/小时（1260kg/s），压力从一些加热应用的14.7磅/ in2（1.0135bar）212F（100℃）到先进循环电厂的4500磅/ in2（310bar）1100F（593℃）。
现代锅炉可根据不同的标准分类。
这些包括最终用途、燃烧方式、运行压力、燃料和循环方式。
大型中心电站的电站锅炉主要用来发电。
它们经过优化设计，可达到最高的热效率。
新机组的关键特性是利用再热器提高整个循环效率。
各种附加的系统也产生蒸汽用于发电及其他过程应用。
这些系统常常利用廉价或免费燃料，联合动力循环和过程，以及余热回收，以减少总费用。
这些例子包括：燃气轮机联合循环（CC）：先进的燃气轮机，将余热锅炉作为基本循环的一部分，以利用余热并提高热效率。
整体煤气化联合循环（IGCC）：在CC基础上增加煤气化炉，以降低燃料费用并将污染排放降到最低。
增压循环流化床燃烧（PFBC）：在更高压力下燃烧，包括燃气净化，以及燃烧产物膨胀并通过燃气轮机做功。
高炉排烟热量回收：利用高炉余热产生蒸汽。
太阳能蒸汽发生器：利用集热器收集太阳辐射热产生蒸汽。
2. 2 Development of Utility Boiler现代660MW燃煤锅炉有大约6000吨的压力部件，包括500千米的受热面管材，3.5千米连接管与联箱和30000个管接头焊口。
这是经过大约50年发展的结果，并形成了煤粉在具有蒸发管束的炉膛燃烧，烟气然后流经对流过热器和热回收表面的基本概念并保留至今。
蒸汽参数的提高，机组容量的增大及燃料燃烧特性的改进都要求在材料、制造技术和运行程序上相应发展。
二战后的一些年里，在电厂安装锅炉的数量多于汽轮机是很常见的，锅炉提供蒸汽到母管然后到汽机。
这种布置反应了锅炉的可用性低于汽轮机。
四十年代后期，随着锅炉可用性的提高，锅炉和汽机开始可以相互配套使用。
锅炉和汽机成套的变化使得再热成为可行，而且伴随着高温钢材的应用，经过蒸汽参数的不断提高，达到了当前的标准循环2400lbf/in2(165.5bar)，568℃和再热568℃。
为充分利用更高的蒸汽参数和获得经济容量，在接下来的15年，机组容量又增加了20倍。
2.3 燃料与燃烧大部分锅炉以煤、天然气和石油作为燃料。
然而，在过去的几十年里，至少在发电领域核能开始扮演一个主要角色。
同样，不断增加的各种生物质和过程副产品也成为蒸汽生产的热源。
这些包括泥煤、木材及木材废弃物、稻草、咖啡渣、稻谷壳、煤矿废弃物（煤屑）、炼钢炉废热甚至太阳能。
现代美国中心电站用燃料主要是煤，或是烟煤、次烟煤或是褐煤。
虽然天然气和燃油也许是未来化石燃料电厂的燃料选择，但煤仍然是今后新的，基本负荷电站锅炉的主要燃料。
2.3.1 煤的分类? 由于煤是一种不均匀的物质，且其组成和特性变动很大，所以建立煤的分类系统是很必要的。
中国煤的性质如表2-1所示。
以煤阶进行煤的分类是典型的做法。
这表现为煤化程度的大小：从褐煤到贫煤、烟煤以及无烟煤。
煤阶表明了煤的地质历史和主要特性。
现在美国应用的煤分类标准是由美国材料试验学会（ASTM）建立的。
其分类是通过煤的工业分析所确定的挥发分和固定碳的含量以及煤的发热量作为分类标准。
这套系统目的在于确定煤的商业使用价值，并提供关于煤燃烧特性的基本信息。
2.3.2 燃烧系统锅炉内化石燃料燃烧以产生蒸汽的技术已成熟多年。
然而，在过去的二十多年中，为了将大气排放和污染降到可行的最低程度，燃烧技术得到了很大程度的提高。
油燃烧系统所有的电站锅炉都燃用油，在燃煤锅炉中点燃煤粉，在煤进入炉膛之前加热炉膛并升压，而在燃油锅炉中则作为主要负荷燃料。
一般地，燃油都是粘度在3500 sec到6500sec的残渣燃料油。
为了有效的燃烧，这些油必须被加热到120~130℃并被良好地分散或雾化成很小的微滴? 燃用渣油，要比一般的馏分油（柴油，汽油等）便宜，但又带来一些问题：酸性污染物和粉尘的排放。
酸性污染问题是由石油中的硫产生的，硫分的含量有时可高达3%。
在20世纪60年代早期，人们对油燃烧器设计进行了深入研究和开发，目的在于解决燃油的排放问题。
由此诞生了一种油燃烧器——“标准燃烧器”，它可以在非常低的过量空气系数下减少碳排放。
为保证锅炉中每个燃烧器获得同样多的空气也做了大量的工作。
目前油燃烧过量空气系数运行水平为2%。
煤燃烧系统煤燃烧器的发展模式同油燃烧器类似，而且重点放在准确控制每只燃烧器煤和油的供给量。
实际中所有的燃煤锅炉都是燃烧煤粉（由磨煤机生产），这些煤粉经过很好的粉碎，然后由空气流（一次风）送入燃烧器。
同以前相比，在流动平衡上的设计成果现在已能使锅炉在较低的过量空气水平下运行，并在不增加飞灰含碳量水平的情况下提高了总的效率煤燃烧系统部件的布置必须根据经济因素和煤的性质来确定。
作为整个燃烧系统设计的性能参数，煤粉细度、磨煤机出口温度、空煤比等都必须达到要求。
低NOx燃烧系统影响NOx生成的因素包括燃料含氮量、火焰峰值温度、火焰中的可用氧量以及气流在锅炉系统中的停留时间。
当煤进入炉膛其化学结构被破坏时，一些煤中的化合氮就作为挥发分被释放出来。
由大气中的氮生成的一氧化氮即“热力型NOx”可以通过减少烟气在高温区域的停留时间而得到控制，这样就会控制燃烧阶段中可用氧量，最后生成的是无害氮而不是NOx。
因为煤在燃烧区的燃烧需要一定的过量氧气以便使所有的碳燃尽，且不含氮的煤是难以获得的，因此NOx的减少必须依靠锅炉和燃烧器的设计来完成。
天然气燃烧系统天然气曾经作为电厂主要燃料。
然而一些年来，没有太多的天然气可供电厂使用，并且人们没有正视这样的事实，即天然气作为一种优质燃料将会重新得到大量应用。
丙烷常常作为一种点火剂，广泛地应用于燃油锅炉和燃煤锅炉中的油燃烧器。
2.3.3 流化床燃烧? 流化床燃烧是煤粉燃烧方式的一种，采用这种燃烧方式时煤在空气中的燃烧发生在流化床中，典型的是循环流化床。
循环流化床最适合于燃烧低成本废弃燃料、低品质或低热量煤。
将煤粒和石灰石投入到床中，石灰石在床内煅烧成石灰。
流化床中主要是石灰和少量的煤，煤焦在其中循环。
运行中的床温很低，只有427℃(800℉)，在这个温度下的热力学环境有利于减少NOx的形成和捕集SO2，使之与CaO 反应生成CaSO4。
对于煤燃烧，蒸汽循环可以是亚临界，也可能是超临界，它们具有相近的发电效率。
循环流化床技术的最大的优点是它在床中捕捉SO2的能力和它对煤质的广泛适应性，其中包括低热量煤、高灰分煤和低挥发分煤，并且在运行中可以改变煤种。
循环流化床锅炉适合与生物质共燃，最近就新建了几台燃烧褐煤的循环流化床机组。
如图2-1所示，目前最常用的流化床技术是循环流化床燃烧技术。
煤和煤焦燃烧的同时，空气携带煤、煤焦、煤灰和脱硫剂通过炉膛。
固体材料通过旋风分离器从烟气中分离出来，然后通过对流烟道部分，烟气把热量传给炉管以产生高压蒸汽。
另一部分蒸汽是由流化床中的高温固体在返回炉膛前放出热量产生的。
炉膛内固体快速运动会引起过量的磨损，因此炉膛底部不安装炉管。
通过低燃烧温度和空气分级燃烧来控制NOx 的生成。
SOx排放通过床中石灰脱硫剂控制。
这些为烟气净化节省了大笔的投资，但是低的SOx排放需要燃烧低硫分煤，并且NOx的排放受燃烧反应的限制。
极低的排放需要额外的烟气净化设备，同时会增加相应的维护成本。
在中国最大的流化床锅炉是330MWe，设计最大的锅炉是600 MWe，但是还没有投建。
2.4 制粉系统煤粉制备与煤粉燃烧技术的发展是同步的。
为了使煤在炉膛中有效燃烧，煤在离开燃烧器时必须被粉碎到一定的大小，这样才能迅速燃烧，这就意味着煤必须被加工成小颗粒，才能被迅速加热到着火温度并和空气良好混合。
? 磨煤机的工作就是把煤磨碎到符合上述要求的合适的大小。
较早的系统使用筒式球磨机磨煤粉，并且在燃烧前利用储仓暂时储存煤粉。
如果对该技术进行改进，去掉中间储仓而将从磨煤机出来的煤粉直接送去燃烧，就会对磨煤机的可靠性有很高的要求。
正压制粉系统中，提供煤粉输送介质的一次风机位于磨煤机前，因而它运送的是清洁空气，不会像排粉风机一样受到侵蚀磨损。
这是正压磨煤系统的主要优点。
然而，磨煤机需要由单独风机提供高于磨煤机内部压力的密封空气。
正压磨煤机的一个缺点是它必须完全由空气密封以避免煤粉泄露到大气中。
相对来说，负压磨煤机的密封标准并不需要这样高，但也不允许漏入过多空气，因为冷空气难以干燥湿煤。
这种方式泄露的空气量也无法测量，如果达到高的空/煤比，遇到明火则可能发生爆炸。
2.4.1 中速磨磨辊在一层耐磨层上滚动，通过移动的磨盘把煤压碎。
磨辊的运动引起煤粒间的相互运动同时磨辊的压力在煤粒间形成压力负荷。
一定压力下在煤粒层上的运动引起摩擦（煤粒依靠摩擦力破碎），这就是磨煤机的工作原理。
耐磨层具有缓冲作用，虽然降低了磨的效率，但也大大降低了磨辊的磨损。
当磨煤区的工作面间距离很近时，比如到了一个颗粒大小，三个部件（磨辊，颗粒，磨盘）间的磨损就会大大增加，磨损速率会是正常磨煤机的100倍。
当带有石英的石头尺寸等于或大于磨层厚度时，也会在运行中发生三部件接触的磨损。
随着磨煤的进行，为了防止过度磨制和降低能耗及磨损，磨好的煤粉从磨煤机中排出。
图2-2是MPS型中速磨的示意图，显示了中速磨煤机的基本组成。
在磨煤机下部有一个转动的台面，称为辊胎的辊子在台面上滚动。
? 原煤由上部的磨煤机给入，然后在磨辊和转动的磨盘间经过，磨辊下的煤就被磨碎了。
离心力加上磨辊对煤层的沉降力共同作用，将部分磨好的煤粉挤出磨盘边缘，由上升的空气流流化并携带这些煤粉。
空气进入点一般称为进风环，喷嘴环或者喉部。
上升的空气流与煤粒混合在进风环上面产生流化的颗粒床。
空气的流速很低，以至于只能携带少部分的煤粒通过床层过滤。
空气和煤粒离开流化床形成了第一步的分离。
预热的空气同时干燥煤粉以保证煤粉的有效燃烧。
立式中速磨是有效的干燥装置。
即使煤中水分到40%也能在中速磨中很好地得到干燥，干燥水分再高些的煤粉也是可能的，但是需要的一次风温度则要求使用特殊材料，并且增加了磨煤机着火的可能。
实际运行的水分最大值是40%（质量），此时要求一次风温高达750℉。
? 空气煤粉向上流动时，由于流动面积增大使流动速度降低，大粒径的煤粒就会回落到磨盘上。
最后的煤粉分离采用磨煤机上部的粗粉分离器，粗粉分离器是利用离心力的分离装置。
风粉混合物以一定角度进入，从而发生旋转并产生离心力。