单选题In a refrigeration system, if the cooling water to the condenser fails, the().Abox temperature solenoid valve will closeBexpansion valve will closeCcompressor will shutdownDking valve will open
单选题
In a refrigeration system, if the cooling water to the condenser fails, the().
A
box temperature solenoid valve will close
B
expansion valve will close
C
compressor will shutdown
D
king valve will open
参考解析
解析:
暂无解析
相关考题:
What is head tank in the closed cooling water system used for?A.for the release of air from the cooling waterB.providing expansion room for heated cooling waterC.a place for implementing water and water treatment agentD.all of the above
If a refrigeration compressor is short cycling on high head pressure, you shouldA.purge the condenser if the waterside is dirtyB.check for proper water flow through the condenserC.increase the high pressure cutout settingD.reduce the cooling water flow
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
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.
High diesel engine cooling water temperatures can be caused by ______.A.air in the cooling systemB.an overhauled water pumpC.correct amount of coolantD.no air in the cooling system
Why is it necessary to have routine testing of the cooling water?A.To ensure that the proper residuals of treatment chemicals, as specified, are maintained all timeB.To trace leakage in the cooling water systemC.It is not necessaryD.To detect the presence of contaminants in the water that may be injurious to the cooling system
单选题Low compressor head pressure in a refrigeration system can be caused by().Ainsufficient condenser cooling waterBexcessive condenser cooling waterCair in the refrigeration systemDexcessive refrigerant in the system
单选题In a closed cooling water system, which of the problems can cause the water pressure to fluctuate?()AAn open vent in the cooling systemBA fouled sea chestCA restricted water passage in the engineDAir entrained in the cooling water
单选题If a large difference exists between the compressor discharge pressure and the pressure corresponding to the existing condensing temperature in a refrigeration system, you should().Aincrease the flow of the cooling water through the condenserBadjust the high pressure cutout to maintain the desired pressureCopen the hot gas bypass temporarily to reduce capacityDpurge non-condensable gases to reduce the excess pressure
单选题The device allowing for the change in volume of the cooling water in a propulsion diesel engine closed cooling system is the ().Afresh water expansion tankBsea water expansion tankCthermostatic expansion valveDjacket water cooler accumulator
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If a refrigeration compressor is short cycling on high head pressure, you should ().Apurge the condenser if the waterside is dirtyBcheck for proper water flow through the condenserCincrease the high pressure cutout settingDreduce the cooling water flow
单选题Where is the cooling water from the compensating tank in the cooling water system of main engine lead to?()Adischarge side of the centrifugal pumpBsuction side of the centrifugal pumpCthe lowest point of the cooling water systemDinlet of the main engine
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High diesel engine cooling water temperatures can be caused by ().Aair in the cooling systemBan overhauled water pumpCcorrect amount of coolantDno air in the cooling system
单选题In a closed cooling system for a turbocharged, four-stroke/cycle diesel engine, fluctuating water pressure can be caused by ()Aimproper venting of the cooling systemBcarrying the expansion tank water level too highCa totally clogged impeller in the cooling water pumpDan incorrectly set cooling system temperature control
单选题The expansion tank for a diesel engine closed cooling system is designed to maintain a constant head on the system and ().Areduce water temperatureBreduce water turbulenceCprovide an air cushionDallow for an increase in water volume as the engine warms up
单选题Which cause of following will not lead to refrigeration plant short-cycle?()Alack of refrigerantBrefrigerant with much waterCset defectively low pressure relayDno cooling water
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If the water level dropped rapidly in the expansion tank of a closed diesel engine cooling water system, you should suspect a ().Aloss of suction in the circulating pumpBleak in the primary cooling systemCbroken raw water pump shaftDburned or cracked piston in one cylinder
单选题Which of the following problems can cause fluctuating pressures in the closed cooling system of a main propulsion diesel engine?()ADefective temperature controls in the systemBCavitation in the cooling water pumpCOpened vent in the cooling systemDRestricted water passages in the engine
单选题Temperature control valves installed in the jacket cooling water system of a diesel engine modulates the rate of water flow through the ().Acooling water pumpBnozzle cooling passagesCcylinder jacketsDheat exchanger
单选题When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should ().Aincrease the amount of cooling water to the condenserBdecrease the amount of cooling water to the condenserCadd more refrigerant to the systemDremove some refrigerant from the system
单选题Which of the following statements is correct for the design and installation of diesel engine cooling water systems?()AAn alarm device with audible and visible signals is required for all cooling water systemsBPropulsion engines with bores over 200 mm are to be fitted with cooling water jacketsCEach totally enclosed cooling system shall be provided with a suitable head tankDDrain cocks are to be provided at the lowest points of all cylinder water jackets
单选题Which of the following may cause that excessively warm water leaves the condenser in a refrigeration plant? () (1) too little cooling water (2) too much cooling water (3) too warm cooler waterA(1)onlyBanyof(1),(2)and(3)Canyof(1)and(3)Danyof(1)and(2)
单选题In the process of the stand-by, warm-up the engine usually through give preheat of which parts of the diesel engine?()Acooling water of the cooling systemBfuel of the FO systemCLO of the LO systemDcooling water of the cooling system and LO of the LO system
单选题If the compressor-discharge temperature is higher than the receiver temperature()Aincrease the amount of cooling water to the condenserBdecrease the amount of cooling water to the condenserCadd more refrigerant to the systemDremove some of the refrigerant from the system