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)
Excessive circulation of the lubricating oil with the refrigerant in a refrigeration system will cause______.
A.carbon deposits on the compressor suction valves
B.the evaporator temperature to increase
C.rapid corrosion of the thermal expansion valve
D.no operating problems
参考答案
更多 “ 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 ” 相关考题
考题
Which of the conditions listed will cause a refrigeration compressor to run constantly without simultaneously decreasing the temperature in the refrigerated space?( )A.Shortage of refrigerant oilB.Slight shortage of refrigerantC.Excessive condenser cooling water flowD.Faulty expansion valve
考题
Moisture is removed from a refrigeration system byA.bleeding refrigerant from the condenserB.opening a drain petcock on the oil separatorC.condensing the water in the heat exchangerD.using a dehydrator cartridge
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
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
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?A.A shortage of liquid refrigerant.B.Excessive frost on the evaporator.C.Excessive condenser cooling water.D.Insufficient condenser cooling water flow.
考题
Sludge may be formed in the oil in the crankcase of a reciprocating air conditioning compressor as a result of ______.A.refrigerant bubbles in the lube oilB.refrigerant reducing the lube oil viscosityC.oxidation(氧化) of the lube oil from overheatingD.reducing the floc or cloud point of the 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The primary purpose of oil control rings on a diesel piston is to()A
provide a reservoir for cylinder lubricationB
pump oil into the combustion space for cylinder coolingC
prevent excessive lubricating oil consumptionD
allow hydraulic oil film formation on the cylinder
考题
单选题An important consideration in selecting a lubricating oil for use in a refrigeration compressor is for the oil to ()A
have a high viscosity indexB
mix readily with refrigerantC
have a high freezing pointD
have a low pour point
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Excessive lubricating oil consumption in a running diesel engine can be caused by ()A
clogged lube oil pipingB
excessive valve-guide clearanceC
high lube oil viscosityD
low lube oil temperature
考题
单选题Moisture is removed from a refrigeration system by().A
bleeding refrigerant from the condenserB
opening a drain petcock on the oil separatorC
condensing the water in the heat exchangerD
using a dehydrator cartridge
考题
单选题If a refrigeration compressor will not start, the reason may be ().A
the pressure regulating valve is not closingB
an excessive lack of refrigerant in the systemC
badly leaking discharge valvesD
worn piston rings
考题
单选题Before charging a refrigeration unit, the refrigerant charging lines should be()A
flushed with clean refrigerant oilB
purged with the refrigerantC
washed with an ammonia and alcohol solutionD
grounded to compressor
考题
单选题If the head pressure of a reciprocating refrigeration compressor is excessive, ().A
the relief valve should open before the high pressure cutoutB
the relief valve should open and allow the excess refrigerant to flow to the receiverC
the high pressure cutout switch should operate before the relief valve opensD
you should close in on the suction valve
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Refrigerant is circulated through a refrigeration system by the ().A
compressorB
condenserC
expansion valveD
evaporator
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Saltwater is typically provided to a refrigeration system to ().A
cool the expansion valveB
prevent refrigerant superheatingC
condense the refrigerant gasD
prevent motor overheating
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A purge recovery system is used in a centrifugal air conditioning or refrigeration system to ()A
purge lube oil from the liquid refrigerantB
recover water purged from the systemC
separate foul gases from the receiverD
purge non-condensable gases without losing refrigerant
考题
单选题Lubricating oil systems for diesel engine journal bearings are usually lubricated by which of the following types of lubricating oil systems?()A
SplashB
GravityC
PressureD
Bypass
考题
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
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