单选题What is the function of thermostatic expansion valve in a compression refrigeration system?（）AnonexistentBfor controlling pressureCfor controlling superheatDfor controlling the solenoid valve
单选题
What is the function of thermostatic expansion valve in a compression refrigeration system?（）
A
nonexistent
B
for controlling pressure
C
for controlling superheat
D
for controlling the solenoid valve
参考解析
解析：
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相关考题：
When replacing a thermostatic expansion valve sensing bulb, it is necessary toA.apply a light film of oil to increase heat transferB.apply a light film of oil to prevent oxidationC.apply a heavy coating of grease to function as a heat sinkD.carefully coat the device with silicone sealant to reduce the effects of convective cooling
A thermostatic expansion valve is properly controlling evaporator superheat. Adjusting this valve to lower the superheat will result in a/anA.evaporator pressure decreaseB.evaporator coil over-feedC.evaporator capacity increaseD.expansion valve diaphragm rupture
单选题During working, thermostatic expansion valve should be （）.Aeither all the way open or all the way closedBnormally fully openCthrottled depending on loadDcontrolled by liquefied pressure
单选题The thermal expansion valve controls the amount of refrigerant that is allowed to flow to the （）.AcompressorBcooling coilsCcondenserDreceiver
单选题If a refrigeration system compressor crankcase is sweating, you should （）.Aadd refrigerant to the systemBadjust the thermal expansion valve to the proper settingCadjust the float valve to the proper holding pressureDopen the hand expansion valve
单选题When you adjust a thermostatic expansion valve, （）.Arefrigerant must be bled off the sensing line before adjustments are madeBall refrigerant must be pumped into the receiver before adjustments are madeCtime must be allowed for conditions to stabilize in the evaporator before further adjustments are madeDall refrigerant must be routed through the dehydrator while changing the superheat setting
单选题A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water （）.Aaround the engineBaround the coolerCto the expansion tankDoverboard
单选题If the operating element of a thermostatic valve installed in a diesel engine cooling system malfunctions, it may result in （）Aa low level in the engine expansion tankBexcessively high coolant pressureCimproper temperaturesDmalfunctioning of the jacket water heater
单选题A ruptured diaphragm in a thermostatic expansion valve will cause the valve to （）.AopenBcloseCremain in its positionDflood the evaporator with refrigerant
单选题The scale trap is located between the （）Aking valve and the expansion valveBsolenoid valve and expansion valveCevaporator and receiverDcompressor and evaporator
单选题Thermostatic expansion valve are （）.Aeither all the way open or all the way closedBnormally openCthrottled depending on loadDcontrolled by suction pressure
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What separate the high pressure side from the low pressure side in a refrigeration system?（）ACondenser and thermal expansion valveBKing and solenoid valvesCCompressor and thermal expansion valveDCondenser and solenoid valve
单选题A thermostatic expansion valve is properly controlling evaporator superheatAdjusting this valve to lower the superheat will result in a/an （）.Aevaporator pressure decreaseBevaporator coil over-feedCevaporator capacity increaseDexpansion valve diaphragm rupture
单选题When the heat load begins to increase, the needle valve of an expansion valve will（）Amove in an opening directionBmove in a closing directionCeither open or closeDnot move at all
单选题A solenoid valve used in a refrigeration system should be installed （）.Awith the axis of the solenoid horizontal, sensing temperature of the box, and upstream of the thermal expansion valveBupright, sensing temperature of the box, and upstream of the thermal expansion valveCupright, sensing temperature of the box, and downstream of the thermal expansion valveDupright, sensing heat of the tail coil, and upstream of the thermal expansion valve
单选题A cracked diaphragm in a thermostatic expansion valve will cause the valve to （）.Areturn to a neutral positionBflood the evaporatorCopenDclose
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The thermostatic valve has a throttling action, that is to say the valve can（）Astop the refrigerant from flowingBforce the refrigerant to flowCcause the refrigerant pressure to riseDcause the refrigerant pressure to fall
单选题Which of the listed statements is a characteristic of the liquid charged power element used with thermostatic expansion valves?（）AAt the designed operating temperature, the liquid refrigerant charge has changed to a vaporBThe liquid refrigerant tends to collect at the bellows or diaphragm and reduces the valve sensitivityCThe sensing bulb is empty of liquid refrigerant charge at the designed operating temperatureDThe sensing bulb is never emptied of liquid refrigerant under normal operating conditions
单选题When the refrigeration demand is small,（）Athe expansion valve will move toward the wide open positionBthe expansion valve will move toward the closing positionCthe feeler bulb will conveys the high temperatureDthe superheat degree will raise
单选题Thermostatic expansion valves can be adjusted for （）.Asuction pressure onlyBhead pressure onlyCsuperheat onlyDsuction pressure and box temperature
单选题To correct the condition of slugging and flooding back in a refrigeration system, it may be necessary to （）.Are-adjust the discharge pressureBclean the expansion valve screenCadd refrigerantDadjust the expansion valve
单选题The low pressure side of a refrigeration system is considered to exist from the （）.Aexpansion valve to the compressorBreceiver to the expansion coilCexpansion valve to the evaporatorDcondenser to the expansion valve
单选题Which of the listed components is considered to separate the high pressure side of a refrigeration cycle from the low pressure side of the cycle?（）AThe condenser and the expansion valveBThe king valve and the solenoid valveCThe compressor and the expansion valveDThe condenser and the solenoid valve
单选题One function of the thermal expansion valve is to（）Aact as a pilot from the solenoid valveBregulate the amount of refrigerant flow to the coilCregulate the water flowDturn the compressor off and on
单选题The jacket water temperature in a diesel engine closed freshwater cooling system is normally controlled by （）Aregulating the level of corrosion inhibitor in the primary cooling systemBthe level of the freshwater expansion tankCvarying the engine load to meet temperature requirementsDthe operation of the thermostatic valve