新版轮机英语操作级lesson 5Fuel oil system

1、1,Lesson 5,FUEL OIL SYSTEM,CHAO HAI PENG,MARINE ENGINEER DEPARTMENT,1. Marine engines must operate successfully on,heavy fuel oils which may,vary,变化,in,quality,质量,and,analysis,成分，分析,depending upon the source,来源,of their,crude oil,原油,and,the refinery,冶炼,processes,2,Accurate,精确的,and,complete,彻底,的，全部的,

2、analysis,成分,are difficult to,obtain,达到，获得,but,specifications,规范，说明,should confirm,确认，确定,that,certain parameters,参数,are not,exceeded,超过,Samples,样品,of the,oil delivered,送,should be kept for,reference,参考，参照,3,Density,密度,of the oil must be given,usually measured at 15.c ), since the,consignment,交付，运送,wi

3、ll be,measured by weight. It will be necessary to,know this to,adjust,调节,centrifuges to,give efficient purification,由于交货时是用重量来度量的，因此必须给出,油的密度（通常为摄氏,15,度下测量的）。这,也是必须知道的参数当调节分油机分油效率,时,Viscosity,黏度,is required, to,calculate,计算,temperatures at which the fuel is,treated,处理,and,injected,喷射,into the engine

4、,Flash point,闪点,for the fuel must be,below 60.c although the,actual value,实际,值,need not be stated. This,minimum,最小,值,is for safety reasons,Other,factors,因素,should also be,considered when selecting a fuel oil,在选用燃油的时候，其他因素也应该考虑,Among those which affect combustion are,the fuel,oils viscosity,燃油黏度,ceta

5、ne,number,十六烷值,and calorific,卡路里,value,发热量,the,sulphur,硫,in it,and its,carbon,碳,residues,残渣,and,ash,灰,are factors that decide the,formation of combustion products,在这些因素中影响燃烧的因素有燃油黏度,十六烷值，和发热量。含硫量，残炭以,及灰分是决定燃烧产物形成的决定因素,and the engines,maintenance,保养,has a,lot to do with its flash and,setting points,凝

6、,点,specific gravity,比重,viscosity,黏,度,water content,水分,and the,mechanical impurities,机械杂质,in it,并且，主机的保养工作和燃油的闪点、凝,点、比重、黏度、含水量以及机械杂质都,有很大关系,The fuel oil system,燃油系统,for a diesel,engine can be considered in two parts,the,fuel supply,供油,and the fuel injection,燃油喷射,systems,Fuel supply deals,with the pro

7、vision of the fuel oil suitable for,use by the injection system,主机的燃油系统可分为两部分,供油系统和,燃油喷射系统,燃油供应提供适合于喷射系统,的燃油,Fuel oil supply,供油,Fuel to be used is first transferred from,storage tanks,储存柜,to a,settling tank,沉淀柜,in which it is heated to allow some,water and sludge to settle out by gravity and,be drai

8、ned off,燃油首先从日用柜驳运到沉淀柜，加热使,部分水分和杂质靠重力沉淀析出，并通过,放残放掉,The fuel is then,passed through,通过,the,purification,分油，分离,system and,discharged,驳运，排放,to a daily tank,日用柜,Settling and service tanks are,lagged,加保温套，防护套,to,conserve,保护，保存,heat,燃油通过分油系统驳到日用柜,为了保温,沉淀柜和日用柜都加了保温防护层,From the,service tanks,日用柜,the,treated

9、,处理过,oil is pumped through a,pressurized fuel system,压力燃油系统,to,the engine,With the oil temperatures necessary for,high,viscosity fuel,高粘度燃油,and the possibility,that a,trace,痕迹、踪迹,of water may still be,present, it is necessary to maintain the engine pump,suction and circulating connections under pres

10、sure to,inhibit,避免，禁止,boiling,沸腾,gasification,气化,and cavitation,气穴,由于高粘度燃油需要保持油温，并且有种水分的残留依然,可能存在，因此必须保持泵的吸口和循环环节有一定压力,从而避免沸腾，气化、气穴现象的发生,The oil first passes to the supply pump which,raises its pressure to about 4 bar; this,pressure is maintained in the circulating,returns,燃油首先经过供给泵加压使其压力达到约,4bar,这个

11、压力在循环回路里被维持,The,circulating,循环,or,booster,增压,pump draws oil from the,primary,初级的,discharge, raising its pressure to 10-12 bar and,delivering it through the heater, viscosity,regulator and fine filter to the main engine fuel,pumps,循环泵或者增压泵从第一级出口吸入油，把,压力加至,10-12bar,通过加热器、黏度控制,器和细滤器最终传至主机燃油泵,The viscos

12、ity regulator,粘度计,controls,the fuel oil temperature in order to provide oil,at correct viscosity for combustion,粘度控制器控制燃油的温度为了提供利于,燃烧的合适黏度的燃油,In large two-stroke engines the fuel oil,injectors will circulate fuel during the period,they are not actually injecting it to the,cylinder,大型二冲程柴油机，燃油喷射器在实际没

13、,有喷射燃油到气缸的时期，会使燃油在其,中循环,This ensures that the system remain fully primed,and at,uniform,统一的，相同的,temperature. The circulated oil is returned to a,buffer,缓冲柜,or,venting,放气,tank,from which it passes either back to the low,pressure part of the system before the,circulating pump suction, or into the,serv

14、ice tank,日用柜,Various,各种,safety devices,安全装置,must be included in the system with alarms to,detect,探查，侦查,loss in oil pressure,low tank level,低油位,etc,Quick closing valves,速闭阀,which can be,operated from outside the machinery space,must be fitted to all tanks and to the,main,inlet,主进口,to the engine. Fuel

15、 pumps,must have,remote switches,遥控装置,by,which they can be stopped in an emergency,Fuel Injection,燃油喷射,The function,功用,of the,fuel injection,system,燃油喷射系统,is to provide the,amount of fuel at the right moment and in a,suitable condition for the combustion,process,燃油喷射系统的功用就是在合适的时间和,合适的情况下给燃烧过程提供一定量的燃

16、,油,That means, the fuel injection system for,diesel engines must be able to supply,a,metered amount,of,一定量,fuel to each,cylinder for each power stroke according to,the,load,负荷,on the engine,这意味着，燃油喷射系统必须能够根据主,机的负荷向柴油机的每个缸在做功冲程提,供一定量的燃油,and must include a timing mechanism to,ensure that delivery of t

17、his fuel,commenced,开始,at the correct moment, and must,have a means to atomize the fuel,同时必须包含一个定时机构从而确保燃油,供应在正确的时刻开始，并且有一定的方,式雾化燃油,The type of the fuel injection system most,commonly used in modern diesel engines is,the jerk pump system,现代柴油机通常所用的燃油系统的形式,是,高压燃油喷射泵系统,In the system,a separate,单独的,inje

18、ction,pump,喷射泵,is provided for each,cylinder which operates once every cycle. The,barrel,套筒,and plunger,柱塞,together,with the cam,凸轮轴,are,dimensioned,定尺寸,to,displaced,置换,fuel at the,rate,速率,it is required in the,combustion,chamber,燃烧室,Ports,开口,in the,barrel in combination,with,结合,slots,槽,in the plung

19、er,determine,决定,the amount of fuel,delivered and the timing of its entry to the,cylinder. Each pump is connected to the,injector, or injectors, serving one cylinder,These,injectors,喷油器,have spring,loaded,弹簧负荷,needle valves,针阀,which are set to ensure that the fuel is raised,to a,sufficiently high,足够高

20、,pressure to,cause,atomization,雾化,when they,automatically open,自动打开,to admit,使,进入,it to the cylinder,The engine is also provided with a governor,调速器,which is designed to,regulate,调节,the engines speed by,adjusting the quantity of oil injected. When the engine runs at,a speed higher or lower than is s

21、et, the governor will act,automatically and reduce or increase the fuel oil supply so,that the engine speed can be adjusted,柴油机也安装有一个调速器，他通过调节燃油喷射量来控,制机器的速度。当机器在比一个比设定速度较高或者较低,的速度运转时，调速器将自动动作，减少或者增加燃油供,应，从而调控机器的速度,The,flyweight,飞重,type governor with a,adjustable spring,可调节的弹簧,is one of,those most co

22、mmonly used for large marine,engines. The,regulating movements,调节动,作,of the flyweights,are transmitted,传输,to the fuel pump,regulating rods,调节杆,by means of,built-in,组装,servomotor,伺服机构,The oil pressure necessary for operating this,governor is delivered by a gear-type oil pump,built into the governor,用

23、来操作调速器的油压是用一个装在调速,器里面的齿轮泵来建立,The general indications of good combustion,are similar in any operation diesel engine: a,clear exhaust, power produced and exhaust,temperatures normal for the,throttle,节流,setting. There should be on uneven,running, knocking from cylinders or the fuel,system,在所有运转的柴油机,其良好

24、燃烧状况的显示通常,是相同的：淡淡的尾气，产生的功率，废气温度,正常。没有不均匀运转，缸内和燃油系统没有敲,击声,Viscosity,黏度,or,resistance to flow,流,动阻力,in a fuel oil is important when,considering combustion. It must be low,enough to ensure,correct atomization,合适,的雾化,at the fuel injector,Since viscosity reduces as temperature is,increased, it will be necessary to heat heavy,fuel oil to reduce its viscosity to about 15cst at,50.C before atomization for combustion,既然黏度随着温度的升高而减小，因此在,燃烧雾化前需要把把重油