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
A hot air start pipe indicates that there is （）.
A
inefficient cooling
B
a leaking air start valve
C
a clogged drain valve
D
a leaking air bottle
参考答案
参考解析
解析：
暂无解析
更多 “单选题A hot air start pipe indicates that there is （）.A inefficient coolingB a leaking air start valveC a clogged drain valveD a leaking air bottle” 相关考题
考题
Man has always wanted to fly.Even as long as eight hundred years ago, an Englishman had tried.He made a (1)of wings from chicken feathers and fixed them to his shoulders.Then he jumped om a tall building.As you can imagine, he did not fly very far.(2) he fell to the ground and broke several bones.The first real attempt at flying took place in France in 1783.The two Mongolian brothers knew that hot air rose.If they couldfill a large balloon(3)hot air, they thought it would rise into the air and fly.They were right.They made a very large hot air balloon of cloth and paper.It measured ten meters it diameter.They filled it with hot air and the balloon got two hundred meters into the air.It fell into earth about three kilometers away.At the next attempt, they (4) passengers use a bal loon to rise into the air and fly.We do not know what the passengers fell about the trip as they were a cock, a duck, and a sheep But we (5) know that the trip lasted eight minutes and the animals landed safely.(完型填空)A.InsteadB.PairC.DoD.ArrangedE.With
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
In an operating diesel engine, which of the following conditions is an indication of a leaking air starting valve?A.Noise coming from that air starting valveB.Continuous operation of the starting air compressorC.Zero air pressure in the air starting systemD.Overheated starting air pipe to the cylinder head
考题
The No.3 air cycle pack temperature indication is______hot.A.being read
B.to read
C.reading
D.read
考题
Which of the following is a reason why Bob, a technician, should install case fans in the front of acomputer case?（）A、It forces hot air out of the PCB、The fan is easier to remove and cleanC、It forces cooler air into the power supply quicklyD、It forces cooler air across the motherboard
考题
单选题Hot gas defrosting uses the hot gas from （） to defrost the evaporator.A
starting air bottlesB
diesel enginesC
boilersD
refrigeration compressors
考题
单选题Air blowing from the intake air filter of an operating air compressor indicates （）.A
broken inlet valvesB
broken discharge valvesC
pulsations in the air distribution systemD
overloading of the air distribution system
考题
单选题During working of an air compressor, （） should be drained.A
oil sumpB
oil separatorC
outlet pipeD
inlet pipe
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In the starting system, the automatic valve is controlled by（）, and the cylinder start valves are controlled by（）A
pilot air；pilot airB
handle；solenoidC
handle；pilot air coming through the distributorD
solenoid；pilot air coming through the distributor
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During working of an air compressor, （） should be drained.A
inter coolerB
cylinderC
outlet pipeD
inlet pipe
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 installed for bilge pumping or ballast duty, centrifugal pumps require a （） to remove air from the suction pipe.A
air chamberB
head lankC
primerD
prime mover
考题
单选题Which condition indicates the air side fouling of an after-cooler on a turbocharged diesel engine?（）A
An increased air temperature differential between the cooler inlet and outletB
A decrease in the air pressure differential across the coolerC
Excessive condensate forming in the air boxD
A decrease in the air temperature differential between the cooler inlet and outlet
考题
单选题（） supplies pilot air to control the cylinder air start valves.A
An air compressorB
An indicator cockC
An air distributorD
A safety valve
考题
单选题Directional intake ports in diesel engines are used to （）.A
reduce air charge turbulenceB
induce air swirlC
deflect hot combustion gas away from the valvesD
oppose the effects of piston induced squish
考题
单选题Which of the following is a reason why Bob, a technician, should install case fans in the front of acomputer case?（）A
It forces hot air out of the PCB
The fan is easier to remove and cleanC
It forces cooler air into the power supply quicklyD
It forces cooler air across the motherboard
考题
单选题In extreme weather conditions, either hot or cold, control of the air conditioning plant presents （） difficulties.A
fewB
littleC
a littleD
less
考题
单选题In an operating diesel engine, which of the following condition is an indication of a leaking air starting valve?（）A
noise coming from that air starting valveB
continuous operation of the starting air compressorC
zero air pressure in the air starting systemD
overheated starting air pipe to the cylinder head
考题
单选题The rising of the exhaust temperature in manifold pipe may NOT result from （）.A
too great a loadingB
fouled turbochargerC
bad combustionD
excessive air
考题
单选题Hot air can hold（）.A
less moisture than cold airB
more moisture than cold airC
the same amount of moisture as cold airD
moisture independent of air temperature
考题
单选题A dazzling white burner flame in the boiler furnace indicates （）.A
no combustionB
deposits in the fuelC
excessive air in the fuelD
cold fuel oil
热门标签
最新试卷
