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
Distortion of the spray pattern of a nozzle or injector may be indicated by a/an（）
A
high firing pressure
B
overload of that particular cylinder
C
smoky exhaust
D
cooling water temperature rise
参考答案
参考解析
解析：
暂无解析
更多 “单选题Distortion of the spray pattern of a nozzle or injector may be indicated by a/an（）A high firing pressureB overload of that particular cylinderC smoky exhaustD cooling water temperature rise” 相关考题
考题
One advantage of the all-purpose nozzle is that it ______.A.can fit any size hoseB.converts a stream of water into a fogC.increases the amount of water reaching the fireD.can spray two streams of water at the same time
考题
Indirect cooling of fuel injector nozzle holders for diesel engines is accomplished primarily byA.heat conduction into the injected fuel oilB.heat conduction into the water jacket wallC.water circulation through passages in the holderD.fuel oil circulation through passages m the holder
考题
第一组Older 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 modern uniflow scavenged engines the fuel 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. The pressures at which the injectors operate vary depending on the engine, but can be as high as 540 bar. Some injectors have internal cooling passages in them extending into the nozzle through which cooling 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 combination of the intensive bore cooling in the cylinder head being close to the valve pockets and by the fuel which is re-circulated through the injector when the follower is on the base of the cam or when the engine is stopped. As well as cooling the injector, re-circulating the fuel when the engine is stopped keeps the fuel at the correct viscosity for injection by preventing it from cooling down. Fuel injectors must be kept in good condition to maintain optimum efficiency, and to prevent conditions arising which could lead to damage within the cylinder. Injectors should be changed in line with manufacturers recommendations, overhauled and tested. Springs can weaken with repeated operation leading to the injector opening at a lower pressure than designed. The needle valve and seat can wear which together with worn nozzle holes will lead to incorrect atomization and dribbling.Modern uniflow scavenged engines have______.A.a single injector mounted in the center of the cylinder headB.several injectors mounted around the external boundary of the cylinder headC.a single injector mounted at the external boundary of the cylinder headD.several injectors mounted in the center of the cylinder head
考题
Springs in fuel injectors will become not strong enough to work because______.A.the injector opens at a lower pressure than designedB.the needle valve and seat wear outC.the nozzle holes wear outD.long time in use
考题
_______can be a direct cause of faulty operation of diesel engine fuel injection nozzles.A.Excessive fuel nozzle holder coolingB.Sediment in the fuel supplyC.Distortion of the fuel spray patternD.Improper atomization of the fuel
考题
An increase in the fuel injection pump discharge pressure can be caused by a/an _______.A.leaking delivery valveB.excessive bearing end playC.plugged injector spray holeD.increased plunger stroke
考题
The difference in water spray pattern between the high-velocity tip and low-velocity applicator used with the all-purpose nozzle is due to ______.A.a difference in water pressureB.the method of breaking up the water streamC.the length of the applicatorD.All of the above
考题
If not attached to the nozzle, each low-velocity spray applicator on a vessel must be stowed__________.A.in a protected area on the main deckB.inside a machinery space near the entranceC.next to the fire hydrant to which the fire hose is attachedD.on a rack inside the quarters near the entrance
考题
单选题In a jerk pump, the amount of fuel that will be forced through the spray nozzle on each upward stroke of the plunger depends on （）A
the pump supply pressureB
the slope of the fuel camC
how the plunger is rotatedD
the number of sleeve segments engaged with the rack
考题
单选题As the plunger moves up, the ports are closed and the fuel （） and delivered to the injector nozzle at very high pressure.A
being compressedB
to be pumped upC
is pressurizedD
are built up
考题
单选题One advantage of the all-purpose nozzle is that it（）.A
can fit any size hoseB
converts a stream of water into a fogC
increases the amount of water reaching the fireD
can spray two streams of water at the same time
考题
单选题The all-purpose nozzle will produce a fog spray when you（）.A
pull the nozzle handle all the way back toward the operatorB
pull the nozzle handle back to a position where the handle is perpendicular to the plane of the nozzleC
push the nozzle handle forward as far as it will goD
insert a fog applicator between the fire hose and nozzle
考题
单选题In the common rail system, excessive pressure in the header may be caused by （）A
improper adjustment of the bypass valveB
a dribble in the fuel injection nozzleC
insufficient leak-off through injection nozzle packingD
a malfunctioning injection nozzle
考题
单选题Diesel engine exhaust temperatures may be used to indicate （）.A
leaking exhaust valvesB
an overloaded cylinderC
a clogged injector nozzleD
all of the above
考题
单选题In a unit injector the amount of fuel that will be forced through the spray nozzle on each stroke of the plunger depends on （）A
the pump supply pressureB
the slope of the fuel camC
how the plunger is rotatedD
the number of sleeve segments engaged with the rack
考题
单选题The difference in water spray pattern between the high-velocity tip and low-velocity applicator used with the all-purpose nozzle is due to（）.A
a difference in water pressureB
the method of breaking up the water streamC
the length of the applicatorD
All of the above
考题
单选题Which of the following problems may occur if the opening pressure of a fuel injection nozzle is greater than specified by the engine manufacturer?（）A
The amount of fuel injected will be increasedB
The start of injection will be retardedC
The nozzle will permit fuel to dribbleD
The spray pattern will be distorted
考题
单选题Indirect cooling of fuel injector nozzle holders for diesel engines is accomplished primarily by （）.A
heat conduction into the injected fuel oilB
heat conduction into the water jacket wallC
water circulation through passages in the holderD
fuel oil circulation through passages in the holder
考题
单选题A defective injector nozzle in a propulsion diesel engine can cause（）A
engine power lossesB
smoking due to unburned fuelC
high exhaust temperature readingsD
all of the above
考题
单选题A distorted spray pattern from a fuel injector can cause a diesel engine to have （）A
higher firing pressureB
more power outputC
lower fuel pressureD
less power output
考题
单选题Faulty operation of diesel engine fuel injection nozzles can be a direct cause of（）.A
excessive fuel nozzle holder coolingB
sediment in the fuel supplyC
distortion of the fuel spray patternD
improper atomization of the fuel
考题
单选题Faulty operation of diesel engine fuel injection nozzles can be directly caused by （）.A
water in the fuel oil supplyB
excessive fuel nozzle holder coolingC
a distorted fuel spray patternD
leakage past the plunger into the oil drain
考题
单选题An increase in the fuel injection pump discharge pressure can be caused by a/an （）A
leaking delivery valveB
excessive bearing end playC
plugged injector spray holeD
increased plunger stroke
考题
单选题If a few injector spray holes become plugged, the result could be （）A
excessive surging at governed speedB
combustion knock under loadC
poor fuel combustionD
all of the above
考题
单选题A fire main system must have enough fire hydrants so that each accessible space may be sprayed with（）.A
a low velocity spray applicatorB
a water spray or solid streamC
at least two spray patterns of waterD
at least 25 psi delivered pressure
考题
单选题If not attached to the nozzle,each low-velocity spray applicator on a vessel must be stowed（）.A
in a protected area on the main deckB
inside a machinery space near the entranceC
next to the fire hydrant to which the fire hose is attachedD
on a rack inside the quarters near the entrance
考题
单选题The 12-foot low-velocity fog applicator（）.A
has a spray pattern 12 feet in diameterB
can be used in conjunction with both 1-1/2 inch and 2-1/2 inch all-purpose nozzlesC
has a 90°bend at its discharge endD
has a screw thread end which connects to the all-purpose nozzle
热门标签
最新试卷
