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
Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor.
A
has continuously for a long period
B
suction pressure is below normal
C
oil level is below normal
D
starts after a long idle period
参考答案
参考解析
解析：
暂无解析
更多 “单选题Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor.A has continuously for a long periodB suction pressure is below normalC oil level is below normalD starts after a long idle period” 相关考题
考题
Crankcase explosions in propulsion diesel engines result from ____.A.the splashing of lubrication oil by the crankshaftB.the dilution of crankcase oil with particles of combustionC.broken fuel lines spraying oil on the crankcaseD.the ignition of unburned fuel and air in the crankcase
考题
Oil oxidation as a result of excessively high lube oil temperature, is harmful to a diesel engine BecauseA.oil foaming will always occurB.large quantities of oil are consumedC.lube oil viscosity is always decreasedD.corrosive by-products are usually formed
考题
Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur when the compressorA.has run continuously for a long periodB.suction pressure is below normalC.oil level is below normalD.starts after a long idle period
考题
Low compressor head pressure in a refrigeration system can be caused by ___.A.insufficient condenser cooling waterB.excessive condenser cooling waterC.air in the refrigeration systemD.excessive refrigerant in the system
考题
If a used lube oil analysis indicates excessive chromate content, this meansA.air filtration is inadequateB.engine coolant is leaking into the lube oilC.fuel oil is leaking into the lube oilD.the piston rings are excessive worn
考题
Sweating of the refrigeration system compressor crankcase is caused by_______ .A.too much superheatB.insufficient superheatC.suction pressure too lowD.excessive refrigerant returning to the compressor
考题
Excessive circulation of the lubricating oil with the refrigerant in a refrigeration system will cause______.A.carbon deposits on the compressor suction valvesB.the evaporator temperature to increaseC.rapid corrosion of the thermal expansion valveD.no operating problems
考题
单选题Excessive lube oil consumption by a reciprocating air compressor can be caused by （）.A
using a slightly dirty air filterB
using oil having an excessive viscosityC
intercooler or after-cooler leaksD
carrying the oil level higher than normal
考题
单选题A dirty intercooler on an air compressor will cause （）.A
damage to the un-loader operating diaphragmB
an increase in current flow to the motorC
high pressure in the receiver and filterD
an excessive consumption of crankcase oil
考题
单选题The sudden reduction of pressure occurring within the crankcase of a refrigeration compressor during starting causes the （）.A
sudden evaporation of wax crystals in the lubricantB
sudden evaporation of entrapped air in the lubricantC
release of refrigerant from the oil/refrigerant mixtureD
release of dissolved lubricant from the refrigerant
考题
单选题An increase in diesel engine crankcase pressure generally indicates excessive（）A
compression pressureB
lube oil header pressureC
scavenge air pressureD
piston ring blow-by
考题
单选题（） that everything in the engine crankcase is correct, start up the crankcase lubricating oil pump.A
To satisfyB
To be satisfiedC
After satisfyingD
After being satisfied
考题
单选题A refrigeration system compressor crankcase is sweating or unusually coldThis is an indication of（）.A
a shortage of refrigerant in the systemB
air in the systemC
an accumulation of liquid refrigerant in the crankcaseD
a shortage of oil in the crankcase
考题
单选题Refrigeration system compressor crankcase sweating is an indication of （）.A
insufficient lube oil circulating through the systemB
excessive circulation of lube oil through the systemC
insufficient refrigerant in the systemD
an overworked compressor
考题
单选题Excessive oil foaming in the crankcase of a refrigeration compressor can result in （）.A
overheated compressor bearingsB
excess lube oil viscosityC
carbon deposits on the compressor piston ringsD
wax crystals forming in the lubricant
考题
单选题In a refrigeration system, foaming of the crankcase oil may cause the （）.A
expansion valve to overfeedB
compressor to knockC
water regulating valve to failD
crankcase drains to plug
考题
单选题Diesel engine ‘blow-by’ into the crankcase is caused by excessive ring（）A
back clearanceB
side clearanceC
gap clearanceD
taper clearance
考题
单选题Foaming of the oil in a refrigeration compressor crankcase is caused by （）.A
refrigerant boiling out of solution from the lube oilB
liquid refrigerant flooding the compressor and systemC
lube oil viscosity being reduced by refrigerant dilutionD
compressor suction pressure suddenly increasing
考题
单选题An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.A
oil foaming in the compressorB
higher than normal suction and discharge pressures with a higher box temperatureC
higher than normal discharge pressure with a normal box temperatureD
the compressor to run continuously
考题
单选题Crankcase explosions in propulsion diesel result from（）A
the splashing of lubrication oil by the crankshaftB
the dilution of crankcase oil with particles of combustionC
broken fuel lines spraying oil on the crankcaseD
the ignition of unburned fuel and air in the crankcase
考题
单选题Excessive oil foaming in the crankcase of a refrigeration compressor at start up can cause（）.A
compressor damage from improper lubricationB
refrigerant absorption by the lubricantC
increased viscosity in the lubricantD
carbon deposit on the compressor suction valves
考题
单选题Crankcase sweating in a refrigeration system is caused by （）.A
a stuck solenoid valveB
a shortage of refrigerantC
too much oil in circulationD
too much superheat
考题
单选题The accumulation of air and other non-condensable gases in a refrigeration system will （）.A
cause a loss of the liquid sealB
create a vapor lock in the liquid receiverC
collect in the condenserD
cause foaming of the oil in the crankcase
考题
单选题A condition that can increase the foaming tendency of lube oil is （）A
excessively high oil temperaturesB
water or moisture contaminationC
fuel dilutionD
life its cylinder relief vales
考题
单选题If a used lube oil analysis indicates excessive fuel dilution, the lube oil should be （）A
changedB
centrifugedC
filteredD
settled
考题
单选题Oil oxidation, as a result of excessively high lube oil temperature, is harmful to a diesel engine because （）A
oil foaming will occurB
large quantities of oil are consumedC
lube oil viscosity is always decreasedD
corrosive by-products are usually formed
考题
单选题Excessive circulation of the lubricating oil with the refrigerant in a refrigeration system will cause （）.A
carbon deposits on the compressor suction valvesB
the evaporator temperature to increaseC
rapid corrosion of the thermal expansion valveD
no operating problems
热门标签
最新试卷
