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
Constant superheat is maintained at the evaporator outlet of a refrigeration coil by a()
A
solenoid valve
B
low pressure cutout switch
C
king valve
D
thermal expansion valve
参考答案
参考解析
解析:
暂无解析
更多 “单选题Constant superheat is maintained at the evaporator outlet of a refrigeration coil by a()A solenoid valveB low pressure cutout switchC king valveD thermal expansion valve” 相关考题
考题
The expansion valve used in a refrigeration system regulates theA.superheat of the gas leaving the compressorB.back pressure in the evaporatorC.temperature in the refrigerated spaceD.degree of superheat of the gas leaving the evaporator
考题
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
考题
______is a precaution which contributes to avoiding trouble under normal operating conditions.A.Constant inspectionB.Keeping constant loadC.Remaining constant temperatureD.Varying speed
考题
Modern marine diesel engines equipped with mechanical fuel injection operate on a combustion phase within the cycle which is ______.A.entirely constant pressureB.entirely constant temperatureC.a combination of constant volume and constant pressureD.a combination of constant temperature and constant pressure
考题
单选题()can be used to prevent hydraulic system overloaded or keep the pressure of oil outlet from pump constant.A
Overflow valveB
Reducing valveC
Balancing valveD
Reducing valve or balancing valve
考题
单选题When you adjust a thermostatic expansion valve, ().A
refrigerant must be bled off the sensing line before adjustments are madeB
all refrigerant must be pumped into the receiver before adjustments are madeC
time must be allowed for conditions to stabilize in the evaporator before further adjustments are madeD
all refrigerant must be routed through the dehydrator while changing the superheat setting
考题
单选题The vacuum maintained in the salt water feed heater shell of a flash-type evaporator is generally accomplished by ().A
a separate air ejector unitB
a direct unimpeded connection between second stage and salt water feed heaterC
either by vacuum drag or an external line from the first stage via a fixed orificeD
the fixed orifice provided in the steam supply line
考题
单选题In a vapor compression refrigeration the evaporating pressure is maintained constant by the action of the (), which removes vapor from the evaporator at the same rate at which it is formed.A
evaporatorB
compressorC
condenserD
none of the above
考题
单选题A flash-type evaporator discharges heated seawater into a chamber that is maintained at a pressure than the vapor pressure of the entering heated seawater, and subsequently the flashed water vapor thereby produced()A
lower condensingB
higher coolingC
lower coolingD
higher condensing
考题
单选题In order to maintain a constant outlet water temperature of 80-85℃ from the engine, a three-way valve is installed()A
at the jacket cooler outlet to control the flux through the engineB
at the jacket cooler outlet to control the flux through the coolerC
at the engine outlet to control the flux through the engineD
at the engine inlet to control the flux through the engine
考题
单选题The diameter of the gravity disc is too big It causes oil to flow through the water outlet We changed the disc and no () is found in the water outlet.A
waterB
oilC
scaleD
ridge
考题
单选题Which of the following conditions indicates the dilution of diesel engine lube oil by fuel oil?()A
Water discharging from the water outlet of the lube oil purifierB
Fuel oil discharging from the water outlet of the lube oil purifierC
Lube oil discharging from the water outlet of the lube oil purifierD
A change in the lube oil viscosity
考题
单选题The bulb for the thermal expansion valve is located()A
in the middle of evaporator coilsB
near the evaporator coil outletC
near the evaporator coil inletD
on the bottom row of evaporator coils
考题
单选题After received the “finished with engine” instruction, which of the following operations is false?()A
shut off the starting air receiver outlet valveB
stop the FO priming transfer pump and shut off the correspondence inlet and outlet valveC
stop the SW pump immediately and shut off the correspondence inlet and outlet valveD
stop the FW pump immediately and shut off the correspondence inlet and outlet valve
考题
单选题One cause of high head pressure occurring in a refrigeration system can be ().A
insufficient cooling water flow to the condenserB
a low refrigerant charge in the systemC
the liquid valve is open too muchD
high evaporator superheat
考题
单选题With a vacuum boiling evaporator, the remainder of sea water fed to the evaporator is pumped out by ().A
a brine pumpB
an air ejectorC
a feed pumpD
distillate pump
考题
单选题The thermal expansion valve reacts directly to the ()A
temperature in the space being cooledB
liquid refrigerant pressure at the solenoid valveC
pressure drop across the evaporator coilsD
refrigerant gas superheat at the coil outlet
考题
单选题A thermostatic expansion valve is properly controlling evaporator superheatAdjusting this valve to lower the superheat will result in a/an ().A
evaporator pressure decreaseB
evaporator coil over-feedC
evaporator capacity increaseD
expansion valve diaphragm rupture
考题
单选题In practice, the refrigerant flow after the evaporator is designed to ensure that the vapor leaving the evaporator is slightly ().A
saturatedB
super-cooledC
wetD
superheated
考题
单选题If the capacity of the refrigeration compressor is too small, the excess vapor will accumulate in the evaporator, causing the pressure to ().A
riseB
fallC
be maintained constantD
None of the above is true
考题
单选题If the speed of a turbocharged diesel engine is maintained constant the turbocharger speed will ()A
decrease until the engine speed increasesB
increase as the load increasesC
decrease as the loadD
increases remain unchanged
考题
单选题The thermal expansion valve responds to the()A
amount of superheat in the vapor leaving the coilB
amount of superheat in the liquidC
temperature in the evaporator coilsD
pressure in the evaporator coils
考题
单选题Modern marine diesel engines using mechanical fuel injection, operate on a combustion cycle which is()A
a combination of constant volume and constant pressureB
a combination of constant temperature and constant pressureC
entirely constant pressureD
entirely constant volume
考题
单选题Modern marine diesel engines equipped with mechanical fuel injection operate on a combustion phase within the cycle which is()A
entirely constant pressureB
entirely constant temperatureC
a combination of constant volume and constant pressureD
a combination of constant temperature and constant pressure
考题
单选题A constant output voltage from an AC generator is maintained by the ().A
prime mover governorB
exciter generatorC
voltage regulatorD
reverse power relay
考题
单选题The sensible heat of air is dependent upon the ().A
dry bulb temperatureB
wet bulb temperatureC
saturation temperatureD
water vapor superheat
热门标签
最新试卷