1、Water supply and Drainage Engineering给水排水工程给水排水工程Unit 9vlearning guidance：v1.Master：配水系统的组成部分及联合形式，配水系统的作用及设计v2.Teaching important point ：配水系统v3.Teaching difficult point：科技英语翻译技巧：否定的译法9.1 INTRODUCTION 给排水工程是城市基础设施的一个组成给排水工程是城市基础设施的一个组成部分。为了保障人民生活和工业生产，城市部分。为了保障人民生活和工业生产，城市必须具有完善的给水和排水系统。必须具有完善的给水和排水
2、系统。给排水分类给排水分类建筑给排水城市排水系统9.2 Part I Distribution SystemsvQuestions:v（1）For what purpose are distribution systems designed?v（2）What are the components consist of a distribution system?一、一、Words and Phrases v1.hydrant/haidrEnt/n.消防栓，消防龙头v2.cavitation/kQviteiSEn/n.气穴现象v3.hydropneumatic/haidrEunju:mQtik/
3、adj.液压气动的，水和空气协同作用的v4.stagnation/stQgneiSEn/n.停滞v5.booster pumps 增压泵v6.meters 水表v7.water hammer 水锤v8.pressure reducing valves 减压阀二、二、Distribution Systems(配水系统配水系统)vThe distribution system consists of booster pumps,meters,storage tanks,control valves,and hydrants.This part of the system is often negl
4、ected because much of it is underground and out of sight,but it needs and deserves almost as much operator attention as source and treatment facilities.v配水管网由增压泵，管道，水表，贮水箱，控制阀和消火栓组成。由于多数配件埋于地下，配水管网往往被忽略不受重视。但事实上配水管网值得像供水设施和水处理设施同样的关注。vAn adequate distribution system is able to provide a sufficient a
5、mount of safe water to all users at a pressure that will satisfy normal needs.It also provides water without undue(过度的)water loss.v优良的配水管网能为用户提供满足日常用水的安全水源，并减少水源流失。vDistribution systems may be generally classified as grid systems,branching systems,or a combination of these.The configuration of the s
6、ystem is dictated primarily by street patterns,topography,degree and type of development of the area,and location of treatment and storage works.v配水系统一般可分为环状管网、枝状管网或这两种的联合形式。给水管网的结构形式主要由街道形式、地形条件、该地区的发展程度、类型及水处理厂和水库的位置等决定。vA grid system is usually preferred to a branching system,since it can furnish
7、 a supply to any point from at least two directions.The branching system does not permit this type of circulation,since it has numerous terminals or dead ends.A grid or combination system can also incorporate loop feeders,which act to distribute the flow to an area from several directions.v一般情况下与枝状管
8、网相比首选环状管网，因为它可以至少从两个方向对任意一点供水。环状管网因为有很多的端点和死水点，所以不会有这样的循环供水方式。环状管网或联合形式还可以合并为环状供水，也就是从多个方向对一个区域分配流量。二、二、Piping MaterialsvA variety of pipe materials are available for use in a public water supply system to carry water under pressure.They include plastic,ductile iron,steel and concrete.Service pipest
9、hose running from the distribution system to a customermay be made of copper,plastic,iron,steel,or brass.v市政给水系统可用各种管道材料负压给水。管道材料包括，塑料，延性铁，钢以及混凝土。给水管由配水管网铺设至用户的管道，可以是铜，塑料，铁，钢或黄铜材质。三、三、ValvesvValves are a very important part of the distribution system because they regulate the flow of water,reduce pr
10、essure,provide air and vacuum relief,blow off or drain water from parts of the system and prevent backflow.v控制阀是配水管网的重要部分，它调控水流，减压，排气，真空保压,分流或溢流泄压和防止逆流。vValves of any size need to be operated slowly.Water hammer is caused by closing the valve too quickly.When water is suddenly stopped,shock waves ar
11、e generated,which cause large pressure increases throughout the system.These shock waves travel quickly and can cause extensive damage,sometimes splitting pipes or blowing fittings completely off the system.Frequently in the operation of valves,conditions cause a partial vacuum or void to occur on t
12、he downstream side of a valve.These voids will fill with low-pressure vapors from the water.v阀门应该轻开轻关。水锤现象由迅速关闭阀门所致。水流急速停止时会产生冲击波，进一步致使给水系统增压。冲击波流动迅速，可产生大面积危害，有时会震裂水管或将管件冲出给水系统。迅速操作阀门会使阀门水流侧形成真空，真空与低压下分离出的气泡相融合。vWhen these pockets implode or collapse,they create a mechanical shock causing pockets of
13、 metal to break away from the valve surface.A noisy or vibrating valve may be an indication that cavitation is occurring,which will eventually result in leaks and a valve unsuitable for service.v当气泡破碎时形成机械冲击，致使阀门内部金属构件脱离阀门。若有噪音或震动表示有气穴现象发生，进而导致系统渗漏和阀门性能减弱。四、四、Pressure Reducing ValvesvPressure reduci
14、ng valves reduce the water pressure by restricting the flow.Pressure on the downstream side of the valve regulates the amount of flow permitted through it.v减压阀通过限制流量来减压。阀门水流侧压力控制通过这一端的水流量。vSmall water systems may have a small amount of storage in the form of a hydropneumatic tankeither a standard pr
15、essure tank with an air/water interface,or a captive air tank.Other systems might have ground level concrete or steel storage tanks or elevated steel tanks which serve the system by gravity.v小型给水系统所需贮水量少，因此用液压气动储箱带气/水界面的标准压力罐，或是自备燃气罐。其他系统用置于地面的混凝土或钢材储罐，或是架空钢材储罐重力给水。vSmall hydropneumatic pressure tan
16、ks,are used to maintain pressure within the distribution system and to prevent well pumps from cycling too frequently.Larger hydropneumatic tanks use on-site,permanent,air charging devices to maintain the needed air pressure within the vessel.v小型液压气动储存罐用来维持给水系统压力和避免井泵运作过快。大型储存罐用换气装置提供所需气压。五、五、Looped
17、 Systems and Dead End Mains Water lines should be installed to loop back into another part of the distribution system.This allows circulation of water to all users.Dead ends should be avoided.The lack of movement of the water in these lines will cause stagnation and result in the growth of slimes an
18、d bacteria,and development of taste and odor problems.v给水管道应被安装在系统间回环，以此为所有用户供水。应尽量避免死水端。不流动会导致水源停滞进而引起细菌滋长，水质变差产生异味。六、六、Leak Detection ProgramvLeak detection programs are an effective way to reduce operating and maintenance costs.If leaks can be detected when they are small,the system may save many
19、 dollars,hours of work and possible property damage.Leaks not only waste water but may create an environment around the pipe which increases corrosion.Once corrosion develops pinhole leaks in the pipe,contamination can be drawn into the system when the pressure in the pipe is reduced.v渗漏检测系统是降低系统安装和
20、维修费用的有效途径。若渗漏在初期就被检测到，可节省下物力财力及可能的财产危害。渗漏不只浪费水资源，它会引起渗漏管道区侵蚀，当腐蚀程度加重管道形成孔状渗漏，在管道内压力变小的条件下污染便会在给水系统内发生。vTo effect the hydraulic design of a water distribution system,information must be available on the anticipated local rates of water consumption,the manner in which these design flows are distribute
21、d geographically,and the required pressure gradients for the system.It should be reemphasized that the designer ought to investigate both the maximum day rate plus fire protection and the maximum hourly rate to determine which will govern the design.v为配水系统做水利设计，需清楚该配水区的预计用水量，不同地段的设计流量，及所要求的气压梯度。应该再次
22、强调的是设计人员要研究包括在内的日最大用水量和每小时最大用水量，以便确定用哪一个量控制设计。vThe spatial distribution of consumption can be estimated by studying population densities,and commercial and industrial use pattern,that are known or predicted for the region.v通过研究人口密度、商业与工业用水格局，能够估算出耗水量的空间分布；对于一个区域来说，人口密度、商业与工业用水格局也可以知道或预测出来。七、Exercise
23、s vI.Read the whole passage and answer the following questions.v1.For what purpose are distribution systems designed?v2.What are the three types distribution systems generally classified?v3.What are the components consist of a distribution system?v4.What is the function of a valve?v5.What is the rea
24、son that causes a water hammer?v6.What is the function of a pressure reducing valve and how does it work?v7.What are the functions of storage reservoirs?v8.What are the functions of loop feeders in a grid or combination system?v9.Should dead ends be avoided?What is the reason?v10.What information mu
25、st be available to effect the hydraulic design of a water distribution system?vII.Fill in the blanks with the information given in the text.v1.The _ consists of booster pumps,meters,storage tanks,control valves,and hydrants.v2.The _is dictated primarily by street patterns,topography,degree and type
26、of development of the area,and location of treatment and storage works.v3.The total amount of water delivered to the customers is usually measured in _(mgd),or in _(gpcd)which is the total number of gallons divided by the number of persons being served.v4.A noisy or vibrating valve may be an indicat
27、ion that _ is occurring,which will eventually result in leaks and a valve unsuitable for service.v5.Small water systems may have a small amount of storage in the form of a _.Other systems might have ground level concrete or steel storage tanks or elevated steel tanks which serve the system _.v6.If i
28、t is necessary to have a dead end line,a _ or a _ should be installed on the end of the line so stagnant water can be routinely discharged.vIII.Translate the following terms into English.v引入管 室内给水系统v 生活给水系统 消防给水系统v 配水器具 .卫生器具v 市政管道 .存水弯v 建筑给水系统 建筑排水系统vIV.Translate the following sentences into Chines
29、e.v1.The function of a drainage system in a building is to remove safely and quickly sanitary sewage,industrial wastes,and rainwater.v2.In locations where sharp changes in topography occur it is common practice to divide the distribution system into two or more service areas or zones.This precludes
30、the difficulty of extremely high pressure in low-lying areas in order to maintain reasonable pressures at higher elevations.v3.Usual practice is to interconnect the various systems,with the interconnections closed off by valves during normal operations.v4.A water supply engineering for a town usuall
31、y includes a storage reservoir at the source of the supply,a pipeline from the storage reservoir to the distribution reservoir near the town,and finally the distribution pipes buries in the street.v5.A pump is a mechanical device that adds energy to water or other liquids.In most water distribution
32、systems,pumps are needed to raise the water in elevation and to move it through the network of water mains under pressure.v6.Sometimes it is necessary to increase the pressure within the distribution system or to raise the water into an elevated storage tank,;booster pumps can be used for this purpo
33、se.v7.Plumbing is the practice,materials,and fixtures used in installing,maintaining,and altering of pipes,appliances,and appurtenances,utilized for potable water supply,sanitary or storm drainage and venting systems.v8.The individual pipes used to collect and transport wastewater are called sewers,
34、and the network of sewers used to collect wastewater from a community is known as a collection system.9.3 Part II Reading MaterialsvText A:House Water-Supply SystemsvText B:Distribution Reservoirs and PumpsvRequirements of reading materials:(it is arranged by teachers)v英语里表示否定意义的词汇、语法手段等和汉语不完全相同。因此，
35、在翻译科技英语资料时，对于否定句须特别注意。要正确翻译英语否定形式，必须对英语各种否定句型的意义正确理解，才能使汉语译文正确表达英语原文的意义。v英语中的否定句型大致上可划分为五类：v1）完全否定（full negative）。常见的否定词有：no,not,none,never,nothing,nobody,nowhere,neither,nor 等。v2）几乎否定（semi negative）。常见的否定词有：hardly，scarcely,seldom,barely,few,little 等。v3）部分否定（partial negative）。常见的否定表达有：not every,not
36、all,not both,not many,not much,not often,not always 等。8.4 Part III Translation of EST(8)-否定的译法否定的译法v4)双重否定（double negative）。常用的否定表达有：no.not,without.not,not.until,never.without,not.too 等。v5）意义上的否定（words with negative implication）。英语中有些单词或词组，虽然形式上是肯定的，但在意义上是否定的。常见的单词有动词、名词、形容词、副词、介词、连词。例如：fail,without
37、,beyond,until,unless,lest,ignorant,refrain,neglect,absence。常见的词组有：but for,free from,short of,far from,too.to(do),but that,rather than,instead of 等。v下面综合探讨一下各类否定句的译法。v1.全部否定的译法全部否定的译法 v英语中用来表示全部否定意义的词或短语很多，主要有以下这些：never,none,not,no,neither,nothing,nobody,nowhere,not at all 等。含有这些词的否定句通常均译成汉语的全部否定句，翻译
38、过程中无须考虑其所修饰的成分以及句子中所占的地位，只要注意译文符合汉语表达习惯即可。vNeither refractory materials nor magnetic materials can be used to make the part.v耐火材料和磁性材料都不适合生产这种零件。vHe can analyze neither of the circuits.v这两个电路他一个也不能分析。vHe knows none of the electronic meters.v这些电子仪表他全都不知道。v2.几乎否定的译法几乎否定的译法 v几乎否定词，通常是以下这些词：hardly,scarc
39、ely,rarely,barely,seldom,few,almost no,little 等。翻译成汉语时，一般可以译成“极少”、“几乎没有”、“几乎不”、“很少”等。如：vIt seldom makes such difference to the user which winding or windings are tapped.v哪个绕组或哪些绕组上有分接头，对使用者来说这没有多大区别。vThe installed capacity in this power plant hardly changes at all.v这个电厂的装机容量几乎没有什么变化。vThere was littl
40、e electric power supply in China before 1949.v在一九四九年之前中国几乎没有什么电力供应。vLittle information is given as to damage of the machine.v关于机器损坏情况的信息极少。vCuriously,Uranus has almost no such excess heat.v奇怪的是，天王星几乎没有这种多余的热量。vMuch of Britains liner fleet rarely sees a British port.v英国远洋货轮很少在本国港口停靠。v3.部分否定的译法部分否定的译法
41、v(1)如果句子中的主语带有不定代词或形容词all,both,each,some,many,every,everybody,everyone,everything 等，并与not 构成否定句，这种句子不表示完全否定，而只是部分否定句子的内容，在翻译时通常译为“不都是”、“并非都”、“不全是”。vAll metals do not conduct electricity equally well.v并非所有金属的导电性能同样好。vEvery electric motor here is not new.v这里的电机不全是新的。vEach transistor in the box is not
42、out of order.v盒子里的晶体管并非每一个都是坏的。vBoth of the instruments are not digital ones.v这两种仪表不全是数字的。vBoth the instruments are not precision ones.v这两件东西不都是精密仪器。v(2)如果否定句中带有副词always,entirely,completely,totally,altogether,often,quite,enough 等，句子也表示部分否定，一般应翻译成“不总是”、“不全是”、“不常”等。vDigital oscilloscopes cannot be oft
43、en used in our experiments.v数字示波器不常用在我们的实验中。vThe water is not hot enough.v水不够热。v4.双重否定的译法双重否定的译法v英语中的双重否定形式通常由否定词no,not,never等表示否定意义的词连用构成，如nowithout,withoutnot,neverwithout,not/nonethe less,not/neverunless,no lessthan,notuntil,notany the less,impossiblewithout等。v有一些双重否定词因其本身含义的确定性，在翻译成汉语时通常译成固定的意思，
44、比如toonot to,not tooto 一般译成“太肯定会”、“必然”、“不要不”等。vWithout electricity,there could be no todays civilization.v没有电也就没有现代文明。vThere is no rule that has no exception.v任何规则都有例外。vThere is no modern communication mean that has no disadvantage.v现代通信手段都有缺点。vNo flow of water occurs unless there is a difference in
45、pressure.v如果没有压差，水也就不会流动。vNow no spaceship cannot be loaded with man.v现在的宇宙飞船都能够载人了。vIt is impossible for electricity to be converted into certain energy without something lost.v电转换成某种能量时不可能不产生损耗。vThere is nothing unexpected in the simulation investigation.v仿真研究的一切都在预料之中。vAll these electric protecti
46、ve devices should not be unboxed or unwrapped until the moment for fitting has arrived.v不到安装这些电气保护装置是不应打开包装箱或包装纸。v5.意义否定的译法意义否定的译法v意义否定即内容否定，是指英语中某些形式上肯定，内容上否定的句子，也有人称其为含蓄否定句。句子中没有否定词，但意义上却是否定的，而且有时否定的语气还很强烈。原因是句中有带否定意义的词或词组，翻译是要把否定的意义明确译出。如：vThe performance of the machine is short of the requiremen
47、ts.v机器的性能没有达到要求。vShort of transformers,they make their own in their lab.v没有变压器，他们在实验室自己制作。vFree from harmonics,some filter appliances should be used in power network.v为了不受谐波的危害，应该在电网中使用一些滤波装置。vThe system of power supply in the city leaves much to be desired.v该市的供电系统非常不完善。vYou must do anything but ta
48、king away this voltmeter.v你绝对不能拿走这个电压表。vThe angularity of the parts is too great for proper assembly.v零件斜度太大，不宜装配。vThe ripple or harmonics in the direct voltage are objectionable in many cases.v在大多数情况下，直流电压中的纹波或谐波是不利的。vElectrons are too small to be seen by us.v电子小得我们看不见。v6.否定转移的译法否定转移的译法v英语中的否定词总是出现
49、在被否定部分的前面，而对其后的部分进行否定。但若是否定词所否定的并不是紧随其后的部分，而是后面的某部分，这就构成了否定转移。有些句子在英语中否定的是谓语，而汉译时则否定谓语；还有一些句子在英语中否定的是谓语，而译成汉语时却否定了状语，在翻译时必须注意到这种差异性才能使译文流畅通顺，符合汉语的表达习惯。v(1)一般的否定转移。vThe motor did not stop because the electricity was off.v电机停止运转，并非因为电源切断了。vThe engine didnt stop because the fuel was finished.v引擎停止运转并非因
50、为燃料耗尽。（否定谓语变为否定状语）vHydroelectric power generation uses no fuel.v水力发电不用燃料。vWe know of no effective way to store solar energy.v我们不知道储存太阳能的有效方法。vAs we know,electricity cannot be conducted by means of insulators.v正如我们所知，电不能靠绝缘体来传导。vWe dont consider that the phase shift is proportional to frequency.v我们认为
