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In an air conditioning system, moisture is removed from the air by ______.
A.filters
B.separators
C.ducted traps
D.dehumidifiers
参考答案
更多 “ In an air conditioning system, moisture is removed from the air by ______.A.filtersB.separatorsC.ducted trapsD.dehumidifiers ” 相关考题
考题
Which of the processes listed would be the most satisfactory method to use to lower the humidity of the air being circulated by an air conditioning system?A.Cooling the air to a temperature just above dew pointB.Heating the air to a point at which moisture will boil off ,then re-cooling itC.Cooling the air to a point below dew point, then reheating itD.Heating the air and then cooling it to a point below dew point
考题
Exhaust gases are generally removed from the cylinders of a two-stroke/cycle diesel engine byA.natural aspirationB.masked intake valvesC.air ceilsD.scavenging air
考题
Restrictions occurring in the small orifices(孔) of pneumatic control system components can be caused by ______.A.moisture in the compressed air supplyB.excessive dryness in the compressed air supplyC.pressure surging in the compressed air receiverD.insufficient lubrication of the system components
考题
The moisture equilibrium chart can be used to determine the ______．A.Absolute moisture content of the air surrounding a hygroscopic cargo when moisture equilibrium existsB.Dew point temperature that the air surrounding a hygroscopic commodity will have when in moisture equilibrium with that commodityC.Enthalpy of the air surrounding a hydroscopic cargo which is in moisture equilibrium with the cargoD.Temperature at which moisture equilibrium will occur in a cargo hold containing a hygroscopic cargo
考题
单选题Air blowing from the intake air filter of an operating air compressor indicates （）.A
broken inlet valvesB
broken discharge valvesC
pulsations in the air distribution systemD
overloading of the air distribution system
考题
单选题If plastic film insulation becomes damaged in air conditioning system, （） may form within the film.A
evaporationB
condensationC
liquefiesD
vaporization
考题
单选题When used in conjunction with a turbocharger, the main function of an after-cooler is to （）A
increase the density of the cylinder air chargeB
prevent turbocharger overheatingC
liminate the need for a pre-coolerD
remove moisture from air compressed by the turbocharger
考题
单选题In an air conditioning system, low head pressure associated with a reciprocating compressor can be the result of （）A
broken valve springsB
tight drive beltsC
high line voltageD
air in the system
考题
单选题In an air conditioning system, moisture is removed from the air by（）A
filersB
separatorsC
ducted trapsD
dehumidifiers
考题
单选题A re-heater in an air conditioning system functions to （）.A
control inlet air temperatureB
control inlet air volumeC
maintain relative humidity at 15%D
restore conditioned air temperature to a comfortable level
考题
单选题A re-heater, as used in an air conditioning system, is designed to control the （）A
chilled water temperatureB
dew point temperatureC
primary air temperatureD
dry bulb temperature
考题
单选题Air or noncondensable gas is removed from a refrigeration system by a （）A
separating chamberB
system of bafflesC
purge valveD
vacuum reducing valve
考题
单选题For the proper control of the air temperature in an air conditioning system using chilled water circulation, which of the listed conditions should remain constant regardless of load changes?（）A
Chilled water system supply temperatureB
Chilled water system return temperatureC
Compressor discharge temperatureD
Compressor suction pressure
考题
单选题请阅读 Passage 1，完成第 21~25小题。Passage 1These days，many large city buildings are equipped with their own air-conditioning systems.These systems help keep the buildings cool，but they can also damage the environment.Since they use a lot of electricity，for instance，they contribute indirectly to global warming.In addition，the water that flows through the systems is often cooled using chemicals called chlorofluorocarbons，or CFCs，that are believed to damage the Earth's ozone layer.Recently，though，a system has been built in the city of Toronto，Canada，that cools buildings with little damage to the environment. In the traditional air-conditioning systems found in most large buildings，water is pumped through the building in a continuous cycle.The water is first cooled to a temperature of 4℃ in machines called chillers.It is then sent to individual units that cool the air in each room.As the water flows through the building，it gradually becomes warmer.Finally，it reaches the roof ，where it is left to cool down naturally in a water tower.After that it is returned to the chillers，where the cycle begins again.Toronto lies on the shore of Lake Ontario，one of North America's Great Lakes，and the new system makes use of cold water taken from about 80 meters below the surface of the lake.At this depth，the water in the lake remains at 4℃ all year round.This is exactly the temperature to which the water in air-conditioning systems is cooled.However，the water from the lake is not pumped directly into the air-conditioning systems.Instead，it is used to cool the water that is already inside the air-conditioning systems.After that，the lake water is added to the city's ordinary water supply.Enwave，the company that developed this deep-lake cooling system，says that it uses 75 percent less energy than traditional air conditioning.And since no CFCs are used，no damage can be caused to the ozone layer.Not every city is located next to a large lake，but experts believe that systems like the one being used in Toronto could be built elsewhere by using other natural sources of cold water.What is the function of the chillers in a traditional air-conditioning system?A
They pump the air continuously to the units in each room.B
They lower the temperature of the water in the system.C
They help the water cool down naturally on the roof .D
They gradually clean the water as it flows through the building.
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As the air passes through the charge air cooler, its temperature may be reduced and moisture condensed, with the condensate in danger of being carried into the engineSo a water separator should be mounted beneath the bottom part of the engine inlet manifoldA water separator is used in order to （）.A
keep the air from being carried into the engineB
keep the moisture from being condensedC
keep the danger from being carded into the engineD
take away the condensate from the air
考题
单选题Clouds form（）.A
as a mass of warm，humid air rises into the atmosphere and cools，condensing moisture into small dropletsB
as winds blow across bodies of water，the sun causes the moisture to be absorbed and move upward forming cloudsC
dry air compresses moisture from the atmosphere into cloudsD
when the relative humidity of the atmosphere is low
考题
单选题The process of removing moisture from air is known as（）.A
humidificationB
dehumidificationC
vaporizationD
evaporation
考题
单选题In reference to air conditioning, when air attains the maximum amount of moisture it can hold at a specific temperature, it is said to be （）.A
superheatedB
saturatedC
condensedD
convected
考题
单选题The moisture equilibrium chart can be used to determine the（）.A
Absolute moisture content of the air surrounding a hygroscopic cargo when moisture equilibrium existsB
Dew point temperature that the air surrounding a hygroscopic commodity will have when in moisture equilibrium with that commodityC
Enthalpy of the air surrounding a hydroscopic cargo which is in moisture equilibrium with the cargoD
Temperature at which moisture equilibrium will occur in a cargo hold containing a hygroscopic cargo
考题
单选题With ducted air conditioning systems, the modern tendency is to use（）A
central air conditioning systemB
high velocity systemC
low velocity systemD
single duct system
考题
单选题Which of the following methods is normally used to control the temperature of air distributed from individual cooling coils in an air conditioning system using a chilled water circulation system?（）A
A room thermostat activates an electric heater at each individual chilled air outlet when necessaryB
Varying the number of passes the air makes across the coilsC
Varying the temperature of the water through the coilsD
Varying the quantity of water flowing through the coils
考题
单选题To prevent the unnecessary loading of an air conditioning system while maintaining the designed dry bulb temperature and relative humidity in an air conditioning system, you should （）A
admit only enough fresh outside air to provide proper ventilationB
reduce the air reheating system loadC
lower the compressor head pressureD
operate the purge recovery unit continuously
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Which of the processes listed would be the most satisfactory method to use to lower the humidity of the air being circulated by an air conditioning system?（）A
Cooling the air to a temperature just above dew pointB
Heating the air to a point at which moisture will boil off ,then re-cooling itC
Cooling the air to a point below dew point, then reheating itD
Heating the air and then cooling it to a point below dew point
考题
单选题The main distribution duct in an air conditioning system which contains the cooling coils and filters is called the（）A
manifoldB
condenserC
chamberD
plenum
考题
单选题Hot air can hold（）.A
less moisture than cold airB
more moisture than cold airC
the same amount of moisture as cold airD
moisture independent of air temperature
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