During sea trial, the main engine well be kept run at load.A.100%B.110%C.85%D.different
During sea trial, the main engine well be kept run at load.
A.100%
B.110%
C.85%
D.different
相关考题：
While sailing in ballast under normal weather and sea condition, the basic parameter which is used to restrict the fuel injection of main engine isA.the exhaust temperatureB.the speed of main engineC.the turbine rotation speedD.the power of main engine
During the dock repair,______should be measured firstly before tail shaft drawn out.A.the sinking of tail shaftB.the clearance of stern bearingC.the total flexure of shaftD.main engine crankshaft deflection
Before "stand by" is rung on the engine telegraph, it is usual to give the main diesel engine a brief trial ahead and astern.A.with powerB.on powerC.with airD.on air
Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?A.Baffle plates that have been bent during prior removalB.Leaks m the cooler tube nestC.Operating the engine while maintaining a high sea water outlet temperatureD.A punctured sea water strainer supplying cooling water to the heat exchanger
材料：Spark erosion is caused by a voltage discharge between the main bearing and journal surface. The cause of the potential is the development of a galvanic element between the ship’s hull, sea water, and the propeller shaft/crankshaft.The oil film acts as a dielectric. The puncture voltage in the bearing depends on the thickness of the oil film. With increasing engine ratings, the specific load in the main bearing is increased. his will reduce the oil film thickness, and enable the discharge to take place at a lower voltage level.Since the hydrodynamic oil film thickness varies through a rotation cycle, the discharge will take place at roughly the same instant during each rotation cycle, i.e. when the film thickness is at its minimum. The roughening will accordingly be concentrated in certain areas on the journal surface. In the early stages, the roughened areas can resemble pitting erosion. but later, as the roughness increases, the small craters will scrape off and pick up white metal-hence the silvery white appearance.Therefore, to ensure protection against spark erosion, the potential level must be kept at maximum 80 mV, which is feasible today with a high efficiency earthing device. If an earthing device is installed, its effectiveness must be checked regularly. Spark erosion is only observed in main bearings and main bearing journals.问题：According to the paragraph one, a voltage between the main bearing and journal surface is produced by______.A.propeller rotationB.leakage from M/E electric control unitC.a galvanic elementD.friction between the main bearing and journal surface______engine ratings increase, the hydrodynamic oil film between the main bearing and journal surface is______.A.The lower/thinnerB.The higher/the thickerC.The lower/thickerD.The higher/thinnerWhen will the spark erosion take place on the journal surface during each rotation cycle?A.when the film thickness is at its minimumB.when the film thickness is at its maximumC.when the engine is on its compression strokeD.when the engine is on its exhaust strokeDuring the engine room watch keeping, which equipment must be noted to ensure protection against spark erosion?A.the antifouling plantB.the earthing deviceC.the main engine electric heating coilsD.the shaft generator请帮忙给出每个问题的正确答案和分析，谢谢！
单选题The rate of cylinder lubricating oil metered to each cylinder of a large low-speed main propulsion diesel engine is （）Athe same, whether at sea, or during maneuveringBadjusted during each hour of operation while at constant RPMChigher at sea than while maneuveringDlower at sea than while maneuvering
单选题Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?（）ABaffle plates that have been bent during prior removalBLeaks in the cooler tube nestCOperating the engine while maintaining a high sea water outlet temperatureDA punctured sea water strainer supplying cooling water to the heat exchanger
单选题Under manoeuvring condition the main engine may run on （）.Agas oilBmarine diesel oilCresidue oilDcrude oil
单选题In modern installations, the main engine and the standby auxiliary engines（）Acan be started at low temperature and are free from preheatingBusually are preheated by steam before being startedCare kept at a constant temperature and free from preheatingDare kept at a low temperature to save energy
单选题The power developed by a large slow-speed main propulsion diesel engine is dependent upon the （）Aquantity of air it takes in and retains in the cylinders during a given time periodBproportion of trapped air that is utilized in the combustion processCthermodynamic efficiency of the engine cycleDall of the above
单选题Why a gearbox is needed in a ship driven by a medium-speed diesel engine?（）ATo reduce the main engine speedBTo increase the main engine speedCTo govern the main engine speedDTo fix the propeller shaft
单选题When ship navigating in rough sea, the first measure taken by the chief engineer to prevent the overload should be（）Acleaning fuel oil, lubricating oil and seawater filterBreducing fuel feeding of the main engine appropriately or reducing the pitch angle of propellerCusing low sea chestDclosing the skylight and the ventilation opening, which doesn’t affect the normal work of equipments
单选题Whether a ship is sailing before the wind or sailing in the rough sea, we must reduce the fuel injection of the main engine.For the former one, it aims to prevent the main engine being（）, while for the later one, it aims to prevent the main engine being（）.Aoverspeed；overloadBoverload；overspeedCover torque；overspeedDlow mechanical efficiency；overload
单选题The load limitation of governor should be reduced when ship navigating at sea, the main reason is to（）Aprevent the diesel engine surgingBprevent governor from being damaged because of swingCreduce the probability of the crank shaft being torsional vibrated and resonatedDprevent the main engine being overload or overspeed
单选题During maneuvering operations for a direct reversing large, low-speed, main propulsion diesel engine, which of the following actions is used to stop the shaft from turning prior to reversing the engine rotation?（）AFlywheel inertiaBAdmission of starting airCThe way of the vesselDsecuring of fuel to the cylinders
单选题During the diesel engine running, the water level of FW expansion tank should normally kept in the （） level of glass tube.Athe highestBabove 3/4C1/2-3/4Dthe lowest
单选题A large, low-speed, main propulsion diesel engine uses sea water to directly cool the （）.Acylinder headsBexhaust valvesCscavenging airDinjectors
单选题UMS are mainly unattended overnight and during this time （） should have control of the main engine.Athe chief engineerBthe engineer on cabin watchCthe bridge officer on watchDthe master
单选题During the watch at sea （） should be logged or recorded in the engine log book.Athe running hours of the cooling water pumpBchief engineer’s orderCthe main parameters of main and auxiliary equipmentDthe position of the vessel
单选题After finished the engine, which of valves cannot be shut off by the duty engineer?（）Afuel valveBthe starting air valveCthe sea chestDthe main sea pump inlet valve
单选题During the diesel engine running, the water level of F.W expansion tank should normally kept in the （） level of glass tube.Athe highestBabove 3/4C1/2 -3/4Dthe lowest
单选题Before "stand-by" is rung on the engine telegraph, it is usual to give the main engine （） ahead and astern.Aa brief trial with turning gearBa brief trial on powerCa long trial by steering gearDone minutes trial with windlass
单选题While sailing under normal weather and sea condition, the basic parameter which is used to restrict the fuel injection of main engine is （）Apower of main engineBturbine rotation speedCspeed of main engineDexhaust temperature
单选题During the watch keeping at sea, at appropriate intervals inspection should be made of （）, auxiliary machinery and steering gear spaces by the duty engineer.Athe main propulsion plantBlifesaving jacketsClifeboat engineDstate of emergency generator
单选题During the dock repair, each sea valve must be disassembled, cleaned and ground well.Before it reassemble the sealing surface between the valve and the valve seat should be checked by （）Achief engineerBsurveyorCthe engineerDthe technique personnel of the shipyard
单选题During sea trial, the main engine well be kept run at load（）A100%B110%C85%Ddifferent