更多"The refrigerant flows through the e"的相关试题:
[单项选择]As the refrigerant passes through the valve orifice, its pressure is reduced and part of the refrigerant turns into （）.
A. liquid
B. oily mixture
C. emulsion
D. vapor
[单项选择]The refrigerant leaves the evaporator of a refrigeration system as a low pressure （）.
A. sub-cooled liquid
B. high temperature liquid
C. oil saturated liquid
D. superheated vapor
[单项选择]Refrigerant is circulated through a refrigeration system by the （）.
A. compressor
B. condenser
C. expansion valve
D. evaporator
[单项选择]When refrigerant leaves the receiver, it flows next on to the （）.
A. evaporator coils
B. liquid strainer
C. compressor
D. condenser
[单项选择]A pressure drop through the refrigerant liquid line may cause （）.
A. solenoid valve to seize
B. compressor to hunt
C. formation of flash gas in the liquid line
D. expansion valve to freeze open
[单项选择]A refrigerant gives up heat when it goes through （）.
A. condenser
B. regurgitate
C. evaporator
D. boil coil
[单项选择]In a （） boiler the water flows through the inside of the tubes while the hot gases pass around the outside.
A. water-tube
B. fire-tube
C. exhaust gas
D. none of the above
[单项选择]Anchor capstans are used in some installation where the cable lifter rotates about a （）.
A. horizontal axis
B. crankshaft
C. vertical axis
D. camshaft
[单项选择]Scale accumulation on evaporator heat exchange surfaces （）.
A. increases brine density
B. increases distillate salinity
C. reduces metal corrosion
D. reduces heat transfer
[单项选择]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
[单项选择]Which of the following chemicals will be used where protection against caustic cracking is required in boiler treatment?（）
A. Sodium hydroxide
B. Sodium carbonate
C. Sodium nitrate
D. Sodium polyphosphate
[单项选择]Less scale formation occurs in a flash evaporator than in a submerged tube evaporator because （）.
A. the distillate produced has greater purity
B. no boiling occurs on heat transfer surfaces
C. evaporation occurs at a higher rate
D. the incoming feed is at a higher temperature
[单项选择]Distilled water from an evaporator may be discharged into a potable water tank （）.
A. through a detachable hose connection
B. after passing through an activated charcoal filter
C. after chemical analysis shows it is fit for consumption
D. through a solenoid operated three-way valve
[单项选择]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 condensing
B. higher cooling
C. lower cooling
D. higher condensing
[单项选择]Insufficient refrigerant in a refrigeration plant may result in （）.
A. high discharge pressure
B. frosting of the crankcase
C. high temperature of the overboard water
D. low suction pressure of compressor
[单项选择]The steam coils in a high pressure evaporator used for saltwater service should be de-scaled with （）.
A. a needle gun
B. soap and water
C. a wire brush
D. a chipping hammer
[单项选择]When the water produced from most evaporator is supplied for drinking purpose, it must be treated to ensure it is biologically pure and （）.
A. slightly acidic
B. slightly alkaline
C. no salty
D. slightly bitter
[单项选择]The demisters installed in a flash-type evaporator serve to （）
A. deaerate the first effect distillate
B. filter the condensed flash vapors
C. deaerate the first and second effect distillate
D. remove small water droplets entrained in the flashed vapor
[单项选择]In the operation of a flash type evaporator equipped with air ejectors,the air and non- condensable gases are evacuated directly from the （）.
A. first stage flash chamber
B. second stage flash chamber
C. first stage after condenser
D. second stage distilling condenser
