新版輪機(jī)英語(yǔ)操作級(jí)lesson5Fuel oil system.

1、1Lesson 5 FUEL OIL SYSTEMCHAO HAI PENGMARINE ENGINEER DEPARTMENT1. Marine engines must operate successfully on heavy fuel oils which may vary (變化） in quality（質(zhì)量） and analysis(成分，分析） depending upon the source（來(lái)源） of their crude oil （原油）and the refinery（冶煉） processes.2、Accurate（精確的）（精確的） and complete（

2、徹底（徹底的，全部的）的，全部的） analysis(成分）成分） are difficult to obtain（達(dá)到，獲得）（達(dá)到，獲得） but specifications （規(guī)范，說(shuō)明）（規(guī)范，說(shuō)明）should confirm（確認(rèn)，確確認(rèn)，確定）定） that certain parameters（參數(shù)）（參數(shù)） are not exceeded（超過(guò)）（超過(guò)）. Samples（樣品）（樣品）of the oil delivered （送）（送）should be kept for reference（參考，參照）（參考，參照）.3、Density（密度）（密度） of the

3、 oil must be given (usually measured at 15.c ), since the consignment（交付，運(yùn)送）（交付，運(yùn)送） will be measured by weight. It will be necessary to know this to adjust（調(diào)節(jié)）（調(diào)節(jié)） centrifuges to give efficient purification.由于交貨時(shí)是用重量來(lái)度量的，因此必須給出由于交貨時(shí)是用重量來(lái)度量的，因此必須給出油的密度（通常為攝氏油的密度（通常為攝氏15度下測(cè)量的）。這度下測(cè)量的）。這也是必須知道的參數(shù)當(dāng)調(diào)節(jié)分油機(jī)

4、分油效率也是必須知道的參數(shù)當(dāng)調(diào)節(jié)分油機(jī)分油效率時(shí)。時(shí)。Viscosity（黏度）（黏度） is required, to calculate（計(jì)算）（計(jì)算） temperatures at which the fuel is treated（處理）（處理） and injected（噴射）（噴射） into the engine. Flash point（閃點(diǎn)）（閃點(diǎn)） for the fuel must be below 60.c although the actual value （實(shí)際（實(shí)際值）值）need not be stated. This minimum（最?。ㄗ钚≈担┲担?is

5、 for safety reasons. Other factors（因素）（因素） should also be considered when selecting a fuel oil. 在選用燃油的時(shí)候，其他因素也應(yīng)該考慮。在選用燃油的時(shí)候，其他因素也應(yīng)該考慮。 Among those which affect combustion are the fuel oils viscosity（燃油黏度）（燃油黏度）, cetane number（十六烷值）（十六烷值） and calorific（卡路里（卡路里） value（發(fā)熱量）（發(fā)熱量）; the sulphur （硫）（硫）in i

6、t and its carbon（碳）（碳） residues（殘?jiān)堅(jiān)?and ash（灰）（灰） are factors that decide the formation of combustion products; 在這些因素中影響燃燒的因素有燃油黏度在這些因素中影響燃燒的因素有燃油黏度，十六烷值，和發(fā)熱量。含硫量，殘?zhí)恳?，十六烷值，和發(fā)熱量。含硫量，殘?zhí)恳约盎曳质菦Q定燃燒產(chǎn)物形成的決定因素及灰分是決定燃燒產(chǎn)物形成的決定因素 。 and the engines maintenance（保養(yǎng)）（保養(yǎng)） has a lot to do with its flash and sett

7、ing points（凝（凝點(diǎn)）點(diǎn)）, specific gravity（比重）（比重）, viscosity（黏（黏度）度）, water content（水分）（水分） and the mechanical impurities（機(jī)械雜質(zhì)）（機(jī)械雜質(zhì)） in it. 并且，主機(jī)的保養(yǎng)工作和燃油的閃點(diǎn)、凝并且，主機(jī)的保養(yǎng)工作和燃油的閃點(diǎn)、凝點(diǎn)、比重、黏度、含水量以及機(jī)械雜質(zhì)都點(diǎn)、比重、黏度、含水量以及機(jī)械雜質(zhì)都有很大關(guān)系有很大關(guān)系The fuel oil system（燃油系統(tǒng)）（燃油系統(tǒng)） for a diesel engine can be considered in two parts

8、- the fuel supply（供油）（供油） and the fuel injection（燃油噴射）（燃油噴射） systems. Fuel supply deals with the provision of the fuel oil suitable for use by the injection system。主機(jī)的燃油系統(tǒng)可分為兩部分主機(jī)的燃油系統(tǒng)可分為兩部分供油系統(tǒng)和供油系統(tǒng)和燃油噴射系統(tǒng)燃油噴射系統(tǒng).燃油供應(yīng)提供適合于噴射系統(tǒng)燃油供應(yīng)提供適合于噴射系統(tǒng)的燃油。的燃油。 Fuel oil supply（供油）（供油） Fuel to be used is first tra

9、nsferred from storage tanks （儲(chǔ)存柜）（儲(chǔ)存柜）to a settling tank（沉淀柜）沉淀柜） in which it is heated to allow some water and sludge to settle out by gravity and be drained off. 燃油首先從日用柜駁運(yùn)到沉淀柜，加熱使燃油首先從日用柜駁運(yùn)到沉淀柜，加熱使部分水分和雜質(zhì)靠重力沉淀析出，并通過(guò)部分水分和雜質(zhì)靠重力沉淀析出，并通過(guò)放殘放掉。放殘放掉。 The fuel is then passed through(通過(guò)）通過(guò)） the purificati

10、on（分油，分離）（分油，分離） system and discharged（駁運(yùn)，排放）（駁運(yùn)，排放） to a daily tank （日用柜）日用柜）. Settling and service tanks are lagged （加保溫套，防護(hù)套）（加保溫套，防護(hù)套）to conserve（保護(hù)，保存）保護(hù)，保存） heat. 燃油通過(guò)分油系統(tǒng)駁到日用柜。燃油通過(guò)分油系統(tǒng)駁到日用柜。 為了保溫為了保溫，沉淀柜和日用柜都加了保溫防護(hù)層。，沉淀柜和日用柜都加了保溫防護(hù)層。 From the service tanks（日用柜）（日用柜） the treated（處理過(guò)） oil is pu

11、mped through a pressurized fuel system（壓力燃油系統(tǒng)） to the engine. With the oil temperatures necessary for high viscosity fuel（高粘度燃油）（高粘度燃油）, and the possibility that a trace(痕跡、蹤跡）痕跡、蹤跡） of water may still be present, it is necessary to maintain the engine pump suction and circulating connections under

12、pressure to inhibit（避免，禁止）（避免，禁止） boiling（沸騰）（沸騰）, gasification（氣化）（氣化） and cavitation（氣穴）（氣穴）. 由于高粘度燃油需要保持油溫，并且有種水分的殘留依然由于高粘度燃油需要保持油溫，并且有種水分的殘留依然可能存在，因此必須保持泵的吸口和循環(huán)環(huán)節(jié)有一定壓力可能存在，因此必須保持泵的吸口和循環(huán)環(huán)節(jié)有一定壓力，從而避免沸騰，氣化、氣穴現(xiàn)象的發(fā)生，從而避免沸騰，氣化、氣穴現(xiàn)象的發(fā)生。 The oil first passes to the supply pump which raises its pressure

13、to about 4 bar; this pressure is maintained in the circulating returns. 燃油首先經(jīng)過(guò)供給泵加壓使其壓力達(dá)到約燃油首先經(jīng)過(guò)供給泵加壓使其壓力達(dá)到約4bar, 這個(gè)壓力在循環(huán)回路里被維持。這個(gè)壓力在循環(huán)回路里被維持。The circulating（循環(huán)） or booster（增壓） pump draws oil from the primary （初級(jí)的）discharge, raising its pressure to 10-12 bar and delivering it through the heater, vis

14、cosity regulator and fine filter to the main engine fuel pumps. 循環(huán)泵或者增壓泵從第一級(jí)出口吸入油，把循環(huán)泵或者增壓泵從第一級(jí)出口吸入油，把壓力加至壓力加至10-12bar，通過(guò)加熱器、黏度控制，通過(guò)加熱器、黏度控制器和細(xì)濾器最終傳至主機(jī)燃油泵。器和細(xì)濾器最終傳至主機(jī)燃油泵。 The viscosity regulator（粘度計(jì)） controls the fuel oil temperature in order to provide oil at correct viscosity for combustion. 粘度控制器

15、控制燃油的溫度為了提供利于粘度控制器控制燃油的溫度為了提供利于燃燒的合適黏度的燃油。燃燒的合適黏度的燃油。 In large two-stroke engines the fuel oil injectors will circulate fuel during the period they are not actually injecting it to the cylinder. 大型二沖程柴油機(jī)，燃油噴射器在實(shí)際沒(méi)大型二沖程柴油機(jī)，燃油噴射器在實(shí)際沒(méi)有噴射燃油到氣缸的時(shí)期，會(huì)使燃油在其有噴射燃油到氣缸的時(shí)期，會(huì)使燃油在其中循環(huán)。中循環(huán)。 This ensures that the sy

16、stem remain fully primed and at uniform （統(tǒng)一的，相同的）temperature. The circulated oil is returned to a buffer （緩沖柜）or venting（放氣） tank from which it passes either back to the low pressure part of the system before the circulating pump suction, or into the service tank（日用柜）. Various（各種） safety devices（安全裝

17、置） must be included in the system with alarms to detect（探查，偵查） loss in oil pressure, low tank level（低油位）, etc. Quick closing valves（速閉閥） which can be operated from outside the machinery space must be fitted to all tanks and to the main inlet（主進(jìn)口） to the engine. Fuel pumps must have remote switches （

18、遙控裝置）by which they can be stopped in an emergency. Fuel Injection 燃油噴射燃油噴射 The function （功用）of the fuel injection system（燃油噴射系統(tǒng)） is to provide the amount of fuel at the right moment and in a suitable condition for the combustion process. 燃油噴射系統(tǒng)的功用就是在合適的時(shí)間和燃油噴射系統(tǒng)的功用就是在合適的時(shí)間和合適的情況下給燃燒過(guò)程提供一定量的燃合適的情況下給燃

19、燒過(guò)程提供一定量的燃油油 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（負(fù)荷） on the engine, 這意味著，燃油噴射系統(tǒng)必須能夠根據(jù)主這意味著，燃油噴射系統(tǒng)必須能夠根據(jù)主機(jī)的負(fù)荷向柴油機(jī)的每個(gè)缸在做功沖程提機(jī)的負(fù)荷向柴油機(jī)的每個(gè)缸在做功沖程提供一定量的燃油。供一定量的燃油。and must

20、 include a timing mechanism to ensure that delivery of this fuel commenced（開(kāi)始） at the correct moment, and must have a means to atomize the fuel。同時(shí)必須包含一個(gè)定時(shí)機(jī)構(gòu)從而確保燃油同時(shí)必須包含一個(gè)定時(shí)機(jī)構(gòu)從而確保燃油供應(yīng)在正確的時(shí)刻開(kāi)始，并且有一定的方供應(yīng)在正確的時(shí)刻開(kāi)始，并且有一定的方式霧化燃油。式霧化燃油。 The type of the fuel injection system most commonly used in modern dies

21、el engines is the jerk pump system. 現(xiàn)代柴油機(jī)通常所用的燃油系統(tǒng)的形式現(xiàn)代柴油機(jī)通常所用的燃油系統(tǒng)的形式 是是高壓燃油噴射泵系統(tǒng)高壓燃油噴射泵系統(tǒng)。 In the system, a separate（單獨(dú)的） injection pump（噴射泵） is provided for each cylinder which operates once every cycle. The barrel （套筒） and plunger (柱塞), together with the cam（凸輪軸）, are dimensioned（定尺寸） to displac

22、ed （置換）fuel at the rate （速率）it is required in the combustion chamber（燃燒室）. Ports（開(kāi)口） in the barrel in combination with（結(jié)合） slots （槽）in the plunger determine （決定）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

23、 cylinder. These injectors（噴油器） have spring-loaded （彈簧負(fù)荷）needle valves（針閥） which are set to ensure that the fuel is raised to a sufficiently high （足夠高）pressure to cause atomization（霧化） when they automatically open （自動(dòng)打開(kāi)）to admit（使進(jìn)入） it to the cylinder.The engine is also provided with a governor（調(diào)速器

24、）（調(diào)速器） which is designed to regulate（調(diào)節(jié)）（調(diào)節(jié)） the engines speed by adjusting the quantity of oil injected. When the engine runs at a speed higher or lower than is set, the governor will act automatically and reduce or increase the fuel oil supply so that the engine speed can be adjusted. 柴油機(jī)也安裝有一個(gè)調(diào)速器

25、，他通過(guò)調(diào)節(jié)燃油噴射量來(lái)控柴油機(jī)也安裝有一個(gè)調(diào)速器，他通過(guò)調(diào)節(jié)燃油噴射量來(lái)控制機(jī)器的速度。當(dāng)機(jī)器在比一個(gè)比設(shè)定速度較高或者較低制機(jī)器的速度。當(dāng)機(jī)器在比一個(gè)比設(shè)定速度較高或者較低的速度運(yùn)轉(zhuǎn)時(shí)，調(diào)速器將自動(dòng)動(dòng)作，減少或者增加燃油供的速度運(yùn)轉(zhuǎn)時(shí)，調(diào)速器將自動(dòng)動(dòng)作，減少或者增加燃油供應(yīng)，從而調(diào)控機(jī)器的速度。應(yīng)，從而調(diào)控機(jī)器的速度。 The flyweight（飛重） type governor with a adjustable spring （可調(diào)節(jié)的彈簧）is one of those most commonly used for large marine engines. The regulat

26、ing movements（調(diào)節(jié)動(dòng)（調(diào)節(jié)動(dòng)作）作） of the flyweights are transmitted（傳輸） to the fuel pump regulating rods（調(diào)節(jié)桿） by means of built-in （組裝）servomotor（伺服機(jī)構(gòu)）. The oil pressure necessary for operating this governor is delivered by a gear-type oil pump built into the governor。 用來(lái)操作調(diào)速器的油壓是用一個(gè)裝在調(diào)速器里面的齒輪泵來(lái)建立。 The gene

27、ral indications of good combustion are similar in any operation diesel engine: a clear exhaust, power produced and exhaust temperatures normal for the throttle （節(jié)流（節(jié)流）setting. There should be on uneven running, knocking from cylinders or the fuel system. 在所有運(yùn)轉(zhuǎn)的柴油機(jī)在所有運(yùn)轉(zhuǎn)的柴油機(jī), 其良好燃燒狀況的顯示通常其良好燃燒狀況的顯示通常是

28、相同的：淡淡的尾氣，產(chǎn)生的功率，廢氣溫度是相同的：淡淡的尾氣，產(chǎn)生的功率，廢氣溫度正常。沒(méi)有不均勻運(yùn)轉(zhuǎn)，缸內(nèi)和燃油系統(tǒng)沒(méi)有敲正常。沒(méi)有不均勻運(yùn)轉(zhuǎn)，缸內(nèi)和燃油系統(tǒng)沒(méi)有敲擊聲。擊聲。 Viscosity（黏度）, or resistance to flow（流動(dòng)阻力）, in a fuel oil is important when considering combustion. It must be low enough to ensure correct atomization（合適的霧化） 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. 既然黏度隨著溫度的升高而減小，因此在燃燒霧化前需要把