网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
If the engine does not start on air, it may be due to （）
A
low compression of the fuel pumps
B
incorrect timing of fuel pumps
C
the starting air valves stuck
D
air-locks in fuel oil pipeline
参考答案
参考解析
解析：
暂无解析
更多 “单选题If the engine does not start on air, it may be due to （）A low compression of the fuel pumpsB incorrect timing of fuel pumpsC the starting air valves stuckD air-locks in fuel oil pipeline” 相关考题
考题
According to the anti -railway group, all the followings are true but ______.A) tunnels are dangerous to public healthB) the noise and the glare of the engine fire may affect people' s nervesC) the rapid speed through the air does damage to people's lungsD) to those with high blood - pressure, the rapid speed of the train causes them to die
考题
If the engine does not start on air, it may be due toA.low compression of the fuel pumpsB.incorrect timing of fuel pumpsC.the starting air valves stuckD.air-locks in fuel oil pipeline
考题
第二组Under normal operation, some lubrication oil mist may be discharged from the air compressor to the air start system. This oil may be from excess compressor cylinder lubrication, from faulty oil scraper rings, or may even be suspended oil vapor contaminating the engine room atmosphere and drawn in at the compressor suction. Oil discharge is kept to a minimum by draining the after cooler, air receiver and starting system. If small quantities of lubrication oil do get passed into the starting air system, they will deposit as thin moist film over internal pipe surfaces but are not readily combustible. If a cylinder non-return valve leak while the engine is in operation, some hot gas, possibly with unburned fuel and cylinder lubrication oil, may be blown through the valve to the adjacent air manifold. With further heating from the leaky valve, this, together with the already deposited oil film, will carbonize and form. incandescent carbon. If starting air is applied to the system while still hot, the high pressure air coming into contact with the burning carbon may cause an explosion. Such an explosion will cause a flame to pass back through the air start pipe system, evaporating the deposited oil film and igniting it in the presence of air. Very high velocities and shockwaves are generated which may rupture pipes and fittings.Alternatively, if excessive oil has entered the air start system, a mixture of air and oil droplets may be discharged through the open cylinder non-return valve during starting. This spray may ignite due to high temperatures in the cylinder, causing a flame through the still open valve to the air manifold.To prevent an explosion, air start valves must be correctly maintained and lubricated to ensure correct timing and free movement with positive closing. Oil in the system must be kept to a minimum, pipe lines must be drained and cleaned internally when necessary and oil discharge from air compressors must be kept to a minimum by good maintenance.The passage is mainly aboutA.crankcase explosionB.scavenge box fireC.starting air pipeD.the danger of explosion in the starting air system
考题
If the engine does start on air, but combustion does not immediately begin, the cause may be _____.A.failure of the fuel pumpsB.starting air pressure too lowC.stop valve in air line closedD.the turning gear still engaged
考题
单选题If an electric motor driven air compressor fails to start, it may be due to a （）.A
leaking discharge valveB
jammed suction valveC
tripped overload relayD
broken discharge un-loader
考题
单选题Due to the large amount of heat picked up by the air in boiler and engine rooms, it would be （） to maintain ambient conditions within the comfort zone by air conditioning.A
possibleB
necessaryC
practicableD
impracticable
考题
单选题Diesel engine starting difficulties due to cold intake air temperatures, can be overcome by using a/an（）A
increase in starting air pressureB
increase in lube oil viscosityC
compression expansion deviceD
jacket water heater
考题
单选题Which of the following may lead to the engine NOT to start on air?（）A
starting air pressure too highB
correct timing of starting air valvesC
three of the six starting valves stuckD
the turning gear disengaged
考题
单选题Which cause of the following can lead to the engine not to start on air?（）A
starting air pressure too highB
correct timing of starting air valvesC
three of the starting valves stuckD
the turning gear disengaged
考题
单选题A diesel engine may fail to start due to （）A
low air charge temperatureB
high cranking speedC
excessive fuel dilution of lube oilD
high compression pressure
考题
单选题An auxiliary diesel engine may fail to start due to（）A
low exhaust back pressureB
high lube oil temperatureC
insufficient cranking speedD
excessive fuel atomization
考题
单选题A diesel engine fails to start due to excessive water in the fuelBefore the engine can be started, the water should be removed from the（）A
fuel linesB
lube oil filterC
crank case pumpD
rocker arm reservoir
考题
单选题The burning of the fuel adds more heat to the air charge, causing it to expand and force the engine piston to do work on the crankshaftWhat does “it” mean in this sentence?（）A
the burningB
the fuelC
the air chargeD
the engine piston
考题
单选题The engine will fail to start unless （）.A
the pressure of the starting air is high enoughB
there is enough air in the air reservoirsC
the air is supplied into the cylinders in the appropriate sequenceD
all of the above
考题
单选题Diesel engine air start valve timing is controlled by（）A
engine operating speedB
an air manifoldC
a hydraulic distributorD
individual cams and valve gear
考题
单选题When attempting to start a main propulsion diesel engine, the engine, the engine turns at the proper speed but will not startYou should check the（）A
starting air pressureB
scavenge air pressureC
over-speed tripD
banjo oiler line
考题
单选题Which of the following may cause that an engine doesnt run on starting air?（）A
too low starting air pressureB
main start valve closedC
neither A nor BD
A and B
考题
单选题If the engine does start on air, but combustion does not immediately begin, the cause may not be （）.A
low compressionB
failure of the fuel pump to discharge fuelC
incorrect timing of fuel pumpD
turning gear being still on
考题
单选题Diesel engine air start system check valves are opened by （）A
an air start camB
cylinder compression pressureC
starting air pressureD
valve springs
考题
单选题Cold weather starting of a diesel engine is more difficult than warm weather starting due to（）A
use of low viscosity oil in cold weatherB
increased moisture content of inlet air in cold weatherC
increased drag of pistons and bearings due to increased oil viscosityD
higher compression pressures reached due to smaller clearances existing in the engine during cold weather
考题
单选题（） in what position the engine stops there will always be at least one of the cylinders with its starting air valve open to admit compressed air to start the engine.A
BecauseB
Owing toC
ForD
No matter
考题
单选题（） is usually driven by the engine camshaft and supplies pilot air to the cylinder air start valve.A
An air receiverB
An operating valveC
An automatic valveD
An air distributor
考题
单选题As for a diesel engine, lack of combustion air may be due to （）.A
fouling turbineB
fuel pump faultsC
lubrication failureD
excessive cooling
考题
单选题If the engine does start on air, but combustion does not immediately begin, the cause may be （）.A
failure of the fuel pumpsB
starting air pressure too lowC
stop valve in air line closedD
the turning gear still engaged
考题
单选题When starting air is admitted, a diesel engine turns over very slowly without firingThe cause may be （）A
an obstruction in an cylinderB
water accumulation in some engine cylindersC
low starting air pressureD
low scavenge air pressure
考题
单选题If the engine of a survival craft does not start，check to see（）.A
that the fuel valve is openB
if the air supply system is openC
if the water sprinkler system is openD
if the limit switch is on
考题
单选题The timing of diesel engine air starting valves is controlled by（）A
the air start valve timing gears and rodsB
a cylinder check valveC
individual cams and valve gearD
an air manifold poppet valve
热门标签
最新试卷
