更多"In a vapor compression refrigeratio"的相关试题:
[单项选择]In a compression refrigeration plant the refrigerant flows from the expansion valve and through the () where it absorbs heat from the space being cooled and becomes a gas or vapor.
A. compressor
B. condenser
C. throttle valve
D. evaporator
[单项选择]In a compression refrigeration cycle, the temperature of the liquid refrigerant experiences its greatest decrease in the().
A. evaporator
B. compressor
C. expansion valve
D. condenser
[单项选择]In a compression refrigeration plant the hot, high pressure refrigerant gas is cooled by the sea water and becomes liquid in the ().
A. compressor
B. condenser
C. throttle valve
D. evaporator
[单项选择]The evaporating pressure in R22 vapor compression refrigeration plant should be () atmospheric.
A. below
B. above
C. equal to
D. much larger than
[单项选择]Refrigeration system compressor crankcase sweating is an indication of ().
A. insufficient lube oil circulating through the system
B. excessive circulation of lube oil through the system
C. insufficient refrigerant in the system
D. an overworked compressor
[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]Some refrigeration systems have chemical moisture indicators installed in conjunction with the sight glass in the liquid lineIf excess moisture is present in the system, the indicator will ()
A. activate the driers
B. change color
C. secure the compressor
D. add a predetermined amount of liquid drier
[单项选择]Badly leaking refrigeration compressor discharge valves will cause().
A. overfeeding of the expansion valve
B. damage to the condenser
C. constant running of the compressor
D. flooding of the receiver
[单项选择]A refrigeration system contaminated with moisture can be affected by ().
A. acid formation
B. sludge formation
C. ice in the expansion valve
D. All of the above
[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]The refrigeration system low pressure cutout switch is actuated by ().
A. an electric system manager
B. a sensing bulb at the tail coil of the evaporator
C. pressure changes in the suction line
D. failure of the king solenoid valve
[单项选择]Saltwater is typically provided to a refrigeration system to ().
A. cool the expansion valve
B. prevent refrigerant superheating
C. condense the refrigerant gas
D. prevent motor overheating
[单项选择]If a refrigeration compressor is running continuously without lowering the temperature in the refrigerated space, the trouble may be ().
A. a shortage of compressor oil
B. warm food in the refrigerator
C. excessive condenser cooling water
D. a shortage of refrigerant
[单项选择]In the refrigeration compressor the temperature of the vapor is () by compression.
A. raised
B. risen
C. reduced
D. maintained constant
[单项选择]If a refrigeration system compressor crankcase is sweating, you should ().
A. add refrigerant to the system
B. adjust the thermal expansion valve to the proper setting
C. adjust the float valve to the proper holding pressure
D. open the hand expansion valve
[单项选择]Sweating of the refrigeration system compressor crankcase is caused by ().
A. too much superheat
B. insufficient superheat
C. suction pressure too low
D. excessive refrigerant returning to the compressor
[单项选择]A refrigeration system compressor crankcase is sweating or unusually coldThis is an indication of().
A. a shortage of refrigerant in the system
B. air in the system
C. an accumulation of liquid refrigerant in the crankcase
D. a shortage of oil in the crankcase
[单项选择]Which of the listed refrigeration system components keeps the refrigerant circulating through the system?()
A. Expansion valve
B. Condenser
C. Evaporator
D. Compressor