轮机英语阅读理解108题.docx

1、轮机英语阅读理解108题 第四章 关 联 题108题Passage 1Valve drive mechanismThe valve drive mechanism commands the inlet and exhaust valves at the required timing.The valve drive mechanism consists of an inlet and exhaust cam follower (8) each suspended in a plunger of the tappet assembly (7), two tubular push rods (4)

2、 with ball joints, two nodular cast iron rocker arms (2) suspended in a rocker arm bearing bracket, two yokes (5) and a yoke guide pins. See Fig. 4-1.The tappet rollers follow the cam profiles and transfer the movements through push rods to the rocker arms. The rocker arms operate the inlet and exha

3、ust valves through yokes (5).Lubrication for the rocker arms comes from the engine s secondary oil supply manifold through drillings in the cylinder head and rocker arm bracket.The tappet assembly receives lubricating oil via channels in the engine block from the main supply manifold. For the roller

4、 and shaft, the oil is supplied through the guiding plunger. To compensate for heat expansion a clearance must exist between the rocker arm and yoke. All adjustments have to be done on a cold engine only.Fig-4-1 Valve drive mechanism1. According to the passage, the best time to adjust the valve clea

5、rance is_. A. before the engine is started B. when the engine is running C. after the engine has just been stopped D. when something has gone wrong with the engine2. The roller and the tappet assembly are lubricated by means of _. A. the main lube system B. the secondary oil system C. the special pu

6、mping system D. the turbine oil system 3. According to the passage, the valve drive mechanism does not include _ * A. tappet rollers B. push rods C. nodular cast iron D. yokes and guide pins4. To close valves tightly, which clearance should be inspected according to the maintenance schedule? A. The

7、one between the cam and the tappet roller. B. Tlie one between the push rods and the ball joints. C. The one between the rocker aims and the yoke D. The one between two tubular push rods. 5. Which statement about the passage is not true? A. All adjustments have to be made on a hot engine only. B. Fo

8、r the roller and shaft, the oil is supplied through the guiding plunger. C. The valve drive mechanism commands the inlet and exhaust valves at the required timing. D. The rocker arms operate the inlet and exhaust valves through yokes.Passage 3Charge air cooler The engine is equipped with a charge ai

9、r cooler. The insert type charge air cooler is mounted in a welded casing (air trunk) . Tlie trunk is bolted to the engine block. Standard is a two-stage cooler mounted. The first stage, through which the charge air flows, is cooled with water from the HT cooling system and cools the charge air till

10、 approx. 90 - 00癈. Tie second stage is supplied with water coming from the LT water system and cools the charge air mrther till the required temperature of approx. 50 X. By controlling the water flow through the LT cooler the charge air temperature can be kept constant at the required temperature. T

11、he circulating coolant water should always be under positive pressure and should be as clean as possible. The operating air temperature should be maintained by controlling the coolant inlet temperature. Whilst the engine is running the air and coolant temperatures and pressures at inlet and outlet s

12、hould be checked and logged periodically. Variations from normal indicate faults developing such as fouling of the film plates or obstruction of the water tubes. Check daily, during operation of the engine, the working of the telltale hole at the free end of the charge air receiver. The function of

13、this hole is to inform the operator the presence of water in the charge air receiver. Under normal condition only compressed air should escape from this hole. 1. According to the passage, the expression HT probably means _. A. HIGH TANK B. HIGH TEMPERATURE C. HEAT TRANSMISSION D. HEAT TRANSFER 2. In

14、 order to maintain the charge air temperature we should control _. A. the coolant inlet temperature coming from the first stage cooler B. the coolant flow coming from the second stage cooler C. the coolant outlet temperature coming from the second stage cooler D. the coolant flow coming from the fir

15、st stage cooler 3. The charge air temperature departing from normal may indicate that _ A. condensate can be formed B. only compressed air should escape from the telltale C. the film plates are becoming dirty or the water tubes are blocked by scale D. cooling water may have been carried into the cyl

16、inders 4. The function of the telltale hole is to _. A. detect whether compressed air has escaped from the hole B. control the coolant inlet temperature C. determine whether the coolant water is under positive pressure D. inform the operator the presence of water in the charge air receiver 5. Which

17、of the following statements is not true? A. The engine is equipped with a charge air cooler. B. A two-stage cooler mounted is standard. C. The first stage is cooled with water from the LH water system. D. The second stage cools the charge air further till about 50C.Passage 19Starting air system The

18、engine is started with compressed air of max 30 bar. Minimum pressure required is 15 bar. A pressure transmitter PT301 mounted on the starting air line before the main starting valve has an indicator in the instrument panel. The supply line from the starting air bottles is provided with a non return

19、 valve and a drain valve. The solenoid valve is electrical (remote control) or manual ( on the engine) operated and send after activation a pilot air signal to the main starting air valve. Interruption of the control air doses the main starting air valve. After the main starting air valve is activat

20、ed the air flows through the flame arrestere to the starting air valves in the cylinder heads. Part of the air Hows via the starting air distributor to each of the starting air valves in the cylinder heads. The starting air distributor controls the timing of opening and closing of the starting air v

21、alves. On the moment the main starting air valve is operated also the governor booster is energized. The main starting air line is provided of a safety valve. Interlock valve is a safety device to avoid an engine start with engagedtuming gear. 1. As the engine is started with compressed air, the cor

22、rect sequence of the following devices being activated is _. solenoid valve; starting air valve; starting air distributor; main starting air valve ; governor booster. A. , B. , C. , D. , 2. The sentence the governor booster is energized ( paragraphs) probably means _. A. the governor booster is supp

23、lied with electric power B. hydraulic oil is pumped into the governor booster C. the governor starts to work before starting the engine D. the governor booster is supplied with pressurized air before starting the engine 3. Which of the following components are attached to the air bottles? A. a press

24、ure transmitter FT 301 B. a non-return valve and a drain valve C. a solenoid valve D. a starting air distributor 4. When the engine is engaged with turning gear,_ can keep the engine from starting A. the control air B. the solenoid valve C. the main starting air valve D. the interlock valve 5. The p

25、hraseflame arresters (paragraph 3 ) probably means_. A. air filters B. fire extinguishers C. stop fire net D. hydrant connectionsPassage 20Starting air distributor The starting air distributor is of the piston type with precision machined inter changeable liners. The liners as well as the pilot pist

26、ons are of corrosion resistant materials. The pilot pistons are controlled by a cam connected to the camshaft end. When the main starting valve opens, the pilot pistons are pressed onto the cam, whereby the pilot piston for the engine cylinder which is in starting position admits control air to the

27、main piston of the starting valve . The starting air valve opens and admits compressed air into the engine cylinder forcing that piston down. Shortly before the exhaust valves are opened the pilot valve interrupts the control air to the starting air valve and starting air to that cylinder is stopped

28、. This procedure will be repeated as long as the main starting valve is activated or until the engine speed is so high that the engine fires. After the main starting air valve is closed, the main starting air system is deaerated, the pressure drops quickly and the springe will lift the pilot plunger

29、s off the cam. Tins means that the pilot plungers touch the cam only during the starting process and thus wear is insignificant. If a pilot liner is worn out, press it out. It may be necessary to heat the distributor up till about 200C as Ixtgtjtg is used for fixing and sealing. 1. According to the

30、passage, the liners of the starting air distributor _. A. can be replaced when worn out B. are made of heat resistant materials C. are welded precisely D. are worn out easily during the starting process 2. During the starting process, when _, the main starting air valve is closed. A. the exhaust val

31、ves in the starting cylinder are opened B. the pilot air to the starting air valve is stopped C. the engine speed reaches fire speed D. the pilot pistons are pressed onto the cam3. When some cylinder of the engine admits compressed air into it, the pilot piston of the starting air distributor should be _. A. separated from the cam B. pressed onto the cam C. lifted off the cam D. pressed onto the cam repeatedly 4. From the passage we know that Loctile is probably_. A. a type of gasket B. a kind of lubricant C. a glue bond D. an anti-corrosion additive 5. Which of the