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1、关联题(132)Passage 1Because there are many fuel oil tanks on a ship,usually a senior engineer will be at the engine room tooperate the filling valves.There will be another group of people on deck to take soundings of the tanks asthe oil fills up.The idea is to fill up the tanks in a systematic way so t
2、hat oil will not overflow and causepollution to the environment.In practice,this can sometimes be quite tricky and all the personnel involved in bunkering need to beextra vigilant.In wintertime,the oil becomes thick,and the level shown on the sounding tapes can be mistakenlyread.When bunkering is do
3、ne at the same time as cargo loading and unloading,the ship tends to heavefrom one side to another.This will cause error in reading of the oil levels.Miscalculation of tank levels,especially when using the ullage method may lead to wrong readings.Valves at the engine room could bewrongly operated,du
4、e to wrong information being relayed from the deck.Sometimes air bubbles trapped inthe sounding pipes can indicate a different oil level from the actual.The supplier may be pumping too fast.The list goes on.1.A senior engineer is an e n g i n e e r.A.who is older than others B.with a high rankC.in c
5、harge or the engine department D.whose sea service is longer than others2.The word“tricky“in the second paragraph means A.deceptive B.alert C.difficult D.clever3.The“wrong information in the last paragraph refers to.A.wrong values of oil thicknessB.wrong figures of cargo loaded or dischargedC.wrong
6、tanks to be soundedD.wrong readings of tank levels4.The last sentence,t4the list goes on.means t hat.A.there are other items on the safety checklist.B.A calibration list should be used for ullage readingsC.there are other difficulties claiming additional watchfulnessD.The supplier may be pumping so
7、fast that the ship is listing continuouslyBCDDPassage 2Circuit breakers must be capable of making an breaking under normal conditions and also abnormalconditions such as short circuit.As the circuit breaker must be able to withstand closing onto a faultconditions without sustaining damage,it is of h
8、eavy construction.Fitted with an over current release andoverloads with time lags,a circuit breaker can be used as follows:to control the output of a generator,as adirect on-line starter and control outgoing feeder circuits.On modern switchboards,“draw out”circuit breakers may be fitted.In the open
9、position the wholecircuit breaker can be wound clear of the bus bars,thus full inspection and maintenance can be achievedwithout the necessity of de-energizing the bus bars.The“plug in“contacts joining the circuit breaker to the bus bars are not capable of taking before anyattempt is made to withdra
10、w it.A mechanical interlock is fitted arranged to trip the circuit breaker beforethe winding handle can be inserted.The breaker also has a mid position.In this position the control circuits are still connected with the busbar connection isolated.The electrical operation of the breaker can then be te
11、sted.Circuit breakers are normally fitted with under voltage protection and tripping is accomplished byshorting,which releases the latching in mechanism.The no-volt coil may also be open circuited by areverse power relay and an overload trip fitted with a time delay.1.A circuit breaker can be used a
12、s follows exce pt.A.to control outgoing feeder circuits B.to act as a direct on line starterC.to take the breaking load on line D.to control the output of a generator2.A draw out circuit breaker refers to a circuit b r e a k e r.A.which can be made clear of the bus bars by using a winding handleB.wh
13、ich can be made clear of the bus bars by plugging in contactsC.whose test can be carried out with the control circuit still connectedD.whose test can be carried out with the bus bar connection isolated3.A mechanical interlock is fi t t ed.A.to take the breaking load when the circuit breaker is being
14、 withdrawnB.to put the circuit breaker,before being withdrawn,in the open positionC.to put the circuit breaker,before being withdrawn,in the mid positionD.to take the breaking load when the contacts join the circuit breaker to the bus bars4.According to this passage,the electrical operation of this
15、kind of circuit breaker can be tested whenA.the control circuits are connected B.the bus bar connection is isolatedC.either Aor B D.both A and BCABDPassage 3The operation of paralleling two alternators requires the voltages to be equal and also in phase.Thealternating current output of any machine i
16、s always changing,so for two machines to operate together theirvoltages must be changing at the same rate or frequency,and must be reaching their maximum(or anyother value)together.They are then said to be“in phase.Use is nowadays made of a synchroscope whenparalleling two a.c.machines.The synchrosc
17、ope has two windings which are connected one to each side ofthe paralleling switch.A pointer of free to rotate and is moved by the magnetic effect of the two windings.When the two voltage supplies are in phase the pointer is stationary in the 12 oclock potion.If the pointeris rotating then a frequen
18、cy difference exists and the dial is marked for clockwise rotation FAST andanti-clockwise rotation SLOW,the reference being to the incoming machine frequency.To parallel an incoming machine to a running machine therefore it is necessary to ensure firstly thatboth voltages are equal.Voltmeters are pr
19、ovided for this purpose.Secondly the frequencies must be broughtinto phase.In practice the synchroscope usually moves slowly in the FAST direction and the parallelingswitch is closed as the pointer reached the 11 oclock position.This results in the incoming machineimmediately accepting a small amoun
20、t of load.A set of three lamps may be provided to enable synchronizing.The sequence method of lampconnection has a key lamp connected across one phase with two other lamps cross connected over the otherphases.If the frequencies of the machines are different the lamps will brighten and darken in rota
21、tion,depending upon the incoming frequency being FAST or SLOW.The correct moment for synchronizing iswhen the key lamp is dark and the other two are equally bright.1.What device is used to parallel two alternators nowadays?A.A pointer.B.Two windingsC.A synchroscope D.Two synchronizing lamps2.When tw
22、o alternators are said to be“in pha s e ,.A.their current outputs are changingB.their voltages area changing at the same rateC.they are connected one to each side of the paralleling switchD.they have the same maximum voltage3.In practice,the paralleling switch is closed as the synchroscope pointer r
23、eaches the 11 oclock positionwhile it is mo v i n g.A.in the FAST section B.in the SLOW sectionC.towards the FAST direction D.towards the SLOW direction4.The correct moment for synchronizing is when.A.three lamps are equally brightB.three lamps darken in rotationC.the key lamp is bright and the othe
24、r two lamps are darkD.the key lamp is dark and the other two lamps are equally brightCBCDPassage 4Older loop scavenged engines may have a single injector mounted centrally in the cylinder head.Because the exhaust valve is in the center of the cylinder head on modem uni flow scavenged engines thefuel
25、 valves(2 or 3)are arranged around the periphery of the head.The pressure at which the injector operates can be adjusted by adjusting the loading on the spring.Thepressure at which the injectors operate vary depending on the engine,but can be as high as 540 bar.Some injectors have internal cooling p
26、assages in them extending into the nozzle through whichcooling water is circulated.This is to prevent overheating and burning of the nozzle tip.Injectors on modern engines do not have internal cooling passages.They are cooled by a combinationof the intensive bore cooling in the cylinder head being c
27、lose to the valve pockets and by the fuel which isre-circulated through the injector when the follower is on the base of the cam or when the engine isstopped.As well as cooling the injector,re-circulating the fuel when the engine is stopped keeps the fuel at thecorrect viscosity for injection by pre
28、venting it from cooling down.Fuel injectors must be kept in good condition to maintain optimum efficiency,and to preventconditions arising which could lead to damage within the cylinder.Injectors should be changed in line withmanufacturers recommendations,overhauled and tested.Springs can weaken wit
29、h repeated operationleading to the injector opening at a lower pressure than designed.The needle valve and seat can wear whichtogether with worn nozzle holes will lead to incorrect atomization and dribbling.1.Modern uniflow scavenged engines have.A.a single injector mounted in the center of the cyli
30、nder headB.several injectors mounted around the external boundary of the cylinder headC.a single injector mounted at the external boundary of cylinder headD.several injectors mounted in the center of the cylinder head2.Cooling water is circulated through in some injectors.A.the nozzle B.the nozzle t
31、ip C.the internal passages D.the fuel re-circulated3.Re-circulating the fuel when the engine is stopped can.A.keep the fuel at the correct viscosity B.cool the injectorC.both A and B D.neither A nor B4.Springs in fuel injectors will become not strong enough to work b e c a u s e.A.the iiijector open
32、s at a lower pressure than designedB.the needle valve and seat wear outC.the nozzle holes wear outD.the springs operate repeatedlyBCCDPassage 5The only attention that heat exchanger should require is to ensure that the heat transfer surfaces remainsubstantially clean and the flow passages generally
33、clear of obstruction.Indication that undue fouling isoccurring is given by a progressive increase in the temperature difference between the two fluids,over aperiod of time,usually accompanied by a noticeable rise m pressure loss at a given flow.Fouling on the sea-water side is the most usual cause o
34、f deterioration m performance.The method ofcleaning the sea-water side surfaces depends on the type of heat exchanger.With shell-and-tube heatexchangers,the removal of the header covers or,in the case of the smaller heat exchangers,the headersthemselves,will provide access to the tubes.Obstructions,
35、dirt,scale etc.,can then be removed,using thetools provided by the heat exchanger manufacturer.Flushing through with fresh water is recommendedbefore a heat exchanger is returned to service.In some applications,such as piston oil cooling,progressivefouling may take place on the outside of the tubes.
36、Most manufacturers recommend a chemical flushingprocess to remove this in situ,without dismantling the heat exchanger.Plate heat exchangers may be cleaned by unclamping the stack of plates and mechanically cleaning thesurface of each plate as recommended by the manufacturers.The plate seals may requ
37、ire replacement fromtime to time and here the manufacturers instructions should be closely followed.1.By which of the following indication,can we conclude that the lube oil-sea water heat exchanger isunduly fouled?A.the heat exchanger lube oil inlet temperature loweringB.the heat exchanger sea-water
38、 outlet pressure riseC.the heat exchanger temperature difference between lube oil and sea water increasingD.the heat exchanger pressure difference between sea water inlet and outlet decreasing2.What is the most usual reason for the fresh water-sea water heat exchanger fouling in the sea water side?A
39、.lube oil sludge accumulating in itB.dirt and scale etc.,formed on the surfacesC.deformation of the tubes and the shell or the platesD.lube oil leakage into sea-water side3.According to the passage,it is recommended that the heat exchanger oil side be cleaned by.A.flushing with chemical solvent with
40、out being dismantledB.brushing mechanically after being disassembledC.flushing with fresh water onlyD.flushing with clean oil only4.According to the passage,which of the following statement is not true?A.the heat exchanging surfaces should be kept substantially cleanB.the heat exchanger flow passage
41、s should be clear of obstruction generallyC.seals for the plate heat exchanger needs to be renewed oftenD.the cleaning process of the plate heat exchanger should be done following our experiences onlyCBADPassage 6Ship recycling contributes to sustainable development and is the environmentally friend
42、ly way ofdisposing of ships with virtually every part of the hull,machinery,equipment,fittings and even furniturebeing re-used.However,while the principle of ship recycling is a sound one,the reported status of workingpractices and environmental standards in recycling facilities often leaves much to
43、 be desired.Such gio wingconcerns about environmental safety,health and welfare matters in the ship recycling industry have resultedin a growing belief that an international instrument to regulate the ship recycling process is urgentlyneeded.Having become aware of the need to reduce the environmenta
44、l,occupational health and safety risksrelated to ship recycling,as well as the need to secure the smooth withdrawal of ships that have reachedthe end of their operating lives,the International Maritime Organization(IMO)has taken action to developa realistic and effective solution to the problem of s
45、hip recycling,which will take into account theparticular characteristics of international maritime transport and the economic realities.1.Which statement of the following is true?A.Ship recycling is sustainable.B.Ship recycling is very friendly to our environment.C.Ship recycling is the best way to
46、dispose the machinery,equipment,fittings and even furniture onboard.D.Ship recycling brings many problems concerning environmental safety,health andoccupational safety.2.Which information is not given in the text?A.Ship recycling contributes to sustainable development.B.The IMO believes that making
47、all international instillment to regulate the ship recyclingprocess is urgently in need.C.An international convention on ship recycling has been adopted.D.The IMO has taken action to develop an effective solution to the problem of ship recycling.3.What is the best explanation to the underline phrase
48、“to secure the smooth withdrawal of ships”？A.To withdraw a ship and make it in a safe condition.B.To secure the life of a ship and recycle it.C.To break a wreck.D.To finish the service of a ship and break it without other problems.4.What is the main problem lied in the ship recycling industry?A.It l
49、ies in the sustainable development.B.It is about how to recycle the ship as they can as possible.C.It is a big problem concerning environment,safety and health.D.The big problem is that ship-recycling will violate the regulations made by IMO.DCACPassage 7Displacement pumps are those where the volume
50、 of the pump chamber is alternately increased to drawthe liquid in from the suction pipe and then decreased to force the liquid out into the delivery pipe.Centrifugal pumps are those wherein an impeller rotating at high speed throws the liquid by centrifugalforce from the center to the periphery of