1.2.2 船舶柴油机的工作原理和基本结构

中华人民共和国海船船员适任考试·同步辅导教材

轮机英语自学题库

D.continuously, together with the turbochargers to ensure enough air to the engine during full speed running

注 一个二冲程柴油机通常安装一个辅助鼓风机，在机动操车和机动速度（到达或离开）时使用。C

286.An increase in power output of a turbocharged diesel engine operating at a constant engine speed result in ______.

A.higher exhaust temperature B.increased turbocharger speed C.higher air box pressure D.any one of the other alternatives 注 在定速运行的增压柴油机增加输出功将导致高的排气温度、增压器速度增加、高的扫气箱压力。D

287.Continuous surging of turbocharger can be caused by _____.

Ⅰ.crash stop of engine;Ⅱ.increased back pressure after TCH(turbocharger); Ⅲ.fouled or damaged turbine nozzle ring

A.Ⅰ B.Ⅱand Ⅲ

C.Ⅰ,ⅡandⅢ D.none of the other alternatives 注 增压器连续的喘振是由增压器的背压增高或喷嘴环脏堵或坏掉了。B 288.A few spots of turbocharger surging can be caused by ______.

Ⅰ.crash stop of engine;Ⅱ.rapid increase of engine speed A.Ⅰonly B.Ⅱonly

C.both Ⅰand Ⅱ D.neither Ⅰnor Ⅱ 注 涡轮增压器间歇喘振可能由紧急刹车和快速提速引起的。C

289. The air required for combustion is taken from the engine room through a filter fitted on the turbocharger. This reduces the risk for too ____ and contamination of the combustion air.

A.high temperatures B.low temperatures C.wet D.dirty

注 燃烧所需的空气由机舱通过安装在增压器上的滤器吸取。这就降低了温度太低和空气被污染的危险。B

290.The difference between a supercharged engine and an un-supercharged engine is that ____ operates at an increased pressure.

A.the later B.the latter C.the former D.the farmer 注 增压柴油机与非增压柴油机之间的区别是前者在高压下运行。C

291.____ is the main reason that reduces the power advantage of a two-stroke engine over a same size four-stroke one to about ____.

A.Inefficient scavenging; twice B.Inefficient scavenging; 1.8 times

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English of marine engineering (Operational Level)

业轮注 主要原因是扫气不足，使二冲程机相对于同型的四冲程机的功率优势降低到机工1.8倍。B

程292.If the engine is naturally aspirated, or is a small high-speed type with a

centrifugal turbocharger, the period of valve overlap, i.e. when both values are 专____ ,will be ____ ,and the exhaust valve will close some 10 ____ top dead center.

A.open; short; after B.closed; short; after C.open; long; before D.closed; long; before

C.Fewer strokes in a circle; twice D.Fewer strokes in a circle; 1.8 times

注 如果主机是自然吸排气或是一个小型的高速机带离心增压器，气阀重叠角即两阀都打开时，将变小，并且排气阀将在上止点后10°关闭。A

293.Gas exchange, which is a basic part of the cycle of an internal combustion engine, is ____.

A.the supply of normal air and removal of compressed air B.the supply of fuel oil and combustion of the atomized oil C.the supply of fresh air and removal of exhaust gases D.the supply of fresh air and removal of extra heat

注 换气是内燃机循环的一个基本部分，是指新鲜空气的供入和废气的排出。C 294. “This increase in charge air density is accomplished on most modern diesel engine types by use of exhaust gas turbo-charging, in which a turbine wheel driven by exhaust from the engine is rigidly coupled to a centrifugal type air compressor.” According to this sentence, we can know that ____ increases charge air density, ____ drives the compressor directly.

A.a modem diesel engine;a turbine wheel B.a modern diesel engine; exhaust gases C.a compressor; an exhaust gas turbocharger D.a compressor;a turbine wheel

注 “在现代柴油机中，使用废气增压器提高了空气密度。在增压器中，由废气驱动的透平机在另一端和离心压气机相连。”从上可知，压气机提高了空气密度，透平机带动压气机。D

295. When the air charge contacts with the cylinders and pistons and mixes with the residual gases, it will ____.

A.increase in temperature B.lose its energy partly

C.expand and do work D.begin to be compressed

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中华人民共和国海船船员适任考试·同步辅导教材

轮机英语自学题库

注 当增压过的空气接触了气缸和活塞，并与剩余的空气混合后，它的温度将升高。A

296.Usually we take the cooling effect of the air flown through the cylinder during the overlap period as ____.

A.inevitable B.harmful C.helpful D.unacceptable 注 通常我们认为在重叠角时间内，气体流过气缸的冷却作用对气缸是有益的。C

297.Why are the scavenging ports drilled in the liners at a certain angle?

A.Because in this way the scavenging air is given a rotary movement.

B.Because the scavenging air will flow into the cylinder at an angle of 20 degrees.

C.Because the scavenging air will flow straightly into the cylinder . D.Because the amount of the scavenging air will be controlled. 注 为什么扫气口在气缸套上开有一定角度？因为这种方式能使扫气气流旋转运动。A

298.Trunk type diesel engine pistons are effectively cooled when heat is ____.

A.radiated through the engine block

B.transferred to water cooled cylinder walls C.conducted through the piston crown D.transferred to escaping exhaust gases 注 筒形柴油机活塞的冷却是将热量传给缸壁冷却水而实现的。B

299. A distance piece, with ground faces, known as a compression plate, may be interposed between the rod and the bearing housing, its thickness being chosen to ensure the correct ____.

A.compression pressure B.compression test

C.compression ratio D.compression clearance 注 压缩片的厚度可以选择，以确保正确的压缩比。C

300.At least ____ cylinders in four-stroke engine will be configured to ensure that the engine can be started with the crankshaft at whatever position. A.6 B.2 C.12 D.8 注 四冲程柴油机要能正常工作至少需要6个气缸。A

扩：At least ____ cylinder in a two-stroke engine will be configured to ensure that the engine can be started with the crankshaft at whatever position. A.6 B.12 C.4 D. 8 注 二冲程柴油机要能正常工作至少需要4个气缸。C

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English of marine engineering (Operational Level)

301. *Crankshafts of medium speed engines are ____ from a single piece of steel. A.unusually solid welded B.never be solid forged

C.almost invariably solid forged D.almost invariably be welded

业轮机工注 中速柴油机的曲轴几乎都是由一块钢整体锻造而成。C

程302. Cross scavenging requires the fitting of ____ to prevent air or exhaust gas escape

when the piston is at the top of the stroke. 专 A.a exhaust valve B.a piston skirt C.a piston crown D.an air suction valve注 横流扫气方式中，需要活塞裙的结构配合，以防止当活塞处在上止点时空气和废气逃逸。B

303. Doors are generally formed in the ____ of the both in-line and Vee engines to give maintenance access to the crankshaft main and connecting rod large end bearing, A. bedplates B.columns(机架) C.cylinder blocks D.safety caps 注 直列式和V形发动机的机架上一般都有维修通道（导门）。B 304.Each cylinder liner on the marine medium speed engines ____. A.is usually cooled by sea water B.can be replaced when worn out

C.is in direct contact with the water in the bore of the cylinder D.cant expand when heated

注 船用柴油机的缸套磨损后可以更换。B

305.Four strokes consist of suction, compression, ____ and exhaust stroke. A.combustion B.condensation C.charging D.evaporation

注 四冲程分别是吸气、压缩、燃烧（膨胀）和排气(combustion=expansion power，firing=working=explosion)。A

306.In a ____ engine the charge of air in the cylinder before compression commences is above atmospheric pressure.

A.pressure charged B.naturally aspirated(白然吸气) C.contaminated D.high speed diesel

注 压缩冲程前，气缸内的空气压力高于大气压，这种发动机必然是增压式的。A

307. In a marine diesel engine the oil sump is ____.

A.just below the crankcase B.the oil cup for the exhaust valve C.the pan for collecting drain fuel oil D.oil circulating pump 注 船用柴油机的油底壳位于曲柄箱之下。A

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