单选题If a liquid sight flow indicator in a refrigeration system shows gas bubbles in motion passing inside of the glass, there is （）.Atoo much refrigerant in the systemBoil entrained in the refrigerantCless than a full charge of refrigerant in the systemDice crystals forming in the refrigerant
单选题
If a liquid sight flow indicator in a refrigeration system shows gas bubbles in motion passing inside of the glass, there is （）.
A
too much refrigerant in the system
B
oil entrained in the refrigerant
C
less than a full charge of refrigerant in the system
D
ice crystals forming in the refrigerant
参考解析
解析：
暂无解析
相关考题：
Some refrigeration systems have chemical moisture indicators installed in conjunction with the sight glass in the liquid line If excess moisture is present in the system, the indicator willA.activate the driersB.change colorC.secure the compressorD.add a predetermined amount of liquid drier
In the refrigeration system, a shortage of refrigerant is indicated byA.the compressor short cycling on high pressure cut out switchB.high suction pressureC.high head pressureD.bubbles in the sight glass
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.
The flash point of a liquid refers to the temperature ______.A.at which a liquid will give off inflammable（易燃的） vaporsB.at which a liquid will burn steadilyC.at which a liquid will explodeD.that a liquid must reach before it will flow readily
单选题Some refrigeration systems have chemical moisture indicators installed in conjunction with the sight glass in the liquid lineIf excess moisture is present in the system, the indicator will （）Aactivate the driersBchange colorCsecure the compressorDadd a predetermined amount of liquid drier
单选题A refrigeration system compressor crankcase is sweating or unusually coldThis is an indication of（）.Aa shortage of refrigerant in the systemBair in the systemCan accumulation of liquid refrigerant in the crankcaseDa shortage of oil in the crankcase
单选题When liquid reaches the compressor of a refrigeration system through the suction line, the condition is called （）.Aflooding backBsuperheatingCoverflowingDrecycling
单选题In an operating refrigeration system low on refrigerant, a liquid line sight glass will（）Abe clearBbe blueCbe light greenDshow bubbles
单选题An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.Arestriction in refrigerant pipingBair and non-condensable gases in the condenserCwater in the refrigerantDflooding back of liquid refrigerant from the evaporator
单选题Refrigerant is normally sub-cooled in a refrigeration or air conditioning system condenser to （）.Amaintain adequate coil back pressureBprohibit flashing in the liquid lineCreduce refrigerant volume in the systemDreduce compressor discharge line loading
单选题Before liquid can flow into a pump, the air in the suction line must be （） sufficiently to cause the liquid to flow into the suction chamber.AfilledBevacuatedCcompressedDcharged
单选题Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）AA shortage of liquid refrigerantBExcessive frost on the evaporatorCExcessive condenser cooling waterDInsufficient condenser cooling water flow
单选题Air entering an air-cooled refrigeration system is indicated by （）.Afrosting of the liquid lineBhigher than normal head pressureCa clear sight glassDabnormally cold reefer boxes
单选题In the refrigeration system, a shortage of refrigerant is indicated by （）.Athe compressor short cycling on high pressure cut out switchBhigh suction pressureChigh head pressureDbubbles in the sight glass
单选题A liquid indicator sight glass is useful in determining whether or not a refrigeration system is sufficiently chargedIt is generally located in the（）.Ahigh pressure liquid lineBlow pressure liquid lineChigh pressure vapor lineDlow pressure vapor line
单选题A liquid sight flow indicator in a refrigeration system is examined and gas bubbles are noted in motion with the fluid flowThis means （）.Athe system is fully chargedBthere is air leaking in from the condenserCice crystals are forming in the refrigerantDthe system contains less than a full charge of refrigerant
单选题Which of the following statements is correct concerning a typical shipboard multi-coil refrigeration system?（）AThe liquid receiver functions to collect and remove non-condensable gasesBA thermostatic expansion valve is used to control refrigerated space temperatureCRefrigerant temperature in an evaporator is directly related to refrigerant pressureDDehydrators must be used continuously in a refrigeration system
单选题The flash point of a liquid refers to the temperature （）Aat which a liquid will give off inflammable vaporsBat which a liquid will burn steadilyCat which a liquid will explodeDthat a liquid must reach before it will flow readily
单选题One cause of high head pressure occurring in a refrigeration system can be （）.Ainsufficient cooling water flow to the condenserBa low refrigerant charge in the systemCthe liquid valve is open too muchDhigh evaporator superheat
单选题The purpose of the refrigeration system low pressure cutout switch is to （）Aprotect the compressor from liquid flood backBprotect the compressor from low discharge pressureCstart and stop the compressor upon system demandDstart the compressor after a drop in the evaporator pressure
单选题The accumulation of air and other non-condensable gases in a refrigeration system will （）.Acause a loss of the liquid sealBcreate a vapor lock in the liquid receiverCcollect in the condenserDcause foaming of the oil in the crankcase
单选题Which of the listed statements is correct concerning refrigeration systems?（）ADehydrators must be used continuously in a refrigeration systemBA 25 ton refrigeration system has the same cooling effect as melting 25 tons of ice in 24 hoursCA thermostatic expansion valve is used to control refrigerated space temperatureDThe liquid receiver functions to collect and remove non- condensable gases
单选题While troubleshooting a refrigeration system for low head pressure, liquid refrigerant flooding back from the evaporator is determined to be the causeIt may be necessary to （）.Achange the expansion valve adjustmentBreadjust the water regulating valve to increase the flow of waterCpurge air from the condenserDclean the waterside of the condenser
单选题A purge recovery system is used in a centrifugal air conditioning or refrigeration system to （）Apurge lube oil from the liquid refrigerantBrecover water purged from the systemCseparate foul gases from the receiverDpurge non-condensable gases without losing refrigerant
单选题The receiver used in a refrigeration system（）Astores liquid refrigerantBcollects non-condensable gasesCallows refrigerant sub-coolingDprevents compressor surging
单选题A pressure drop in the liquid line of a refrigeration system may cause（）Athe solenoid valve to seizeBthe compressor to huntCflash gas to form in the liquid lineDthe expansion valve to freeze open
单选题The presence of bubbles in a refrigeration system liquid line may （）.Apromote refrigerant dehydrationBbe absorbed in the receiverCcause low condensing pressureDcarry moisture and lead to corrosion