更多"The clearance volume for a single s"的相关试题:
[单项选择]Clearance volume scavenging in a turbocharged, four-stroke/cycle diesel engine is accomplished （）.
A. during the valve overlap period
B. with only the exhaust valve open
C. at a pressure below atmospheric
D. without cooling the cylinders or pistons
[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]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]Insufficient end clearance on newly fitted piston rings in a diesel enginewill cause the rings to（）
A. jam in the most worn part of the cylinder when the rings expand
B. break in the most worn part of the cylinder when the rings expand
C. wear eccentrically on the side opposite the end gap
D. overheat and jam at the top center on the combustion stroke
[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]Short cycling of a refrigeration compressor refers to （）.
A. frequently grounding out
B. frequently starting and stopping
C. running too fast
D. running too slow
[单项选择]If the refrigeration compressor crankcase is sweating, the cause may be due to （）.
A. a shortage of refrigerant
B. the compressor running continuously
C. liquid refrigerant returning to the compressor
D. the compressor short cycling on the high pressure cutout
[单项选择]The compressor suction line conveys the refrigerant vapor from （） to （）.
A. condenser；evaporator
B. evaporator；compressor
C. compressor；condenser
D. None of the above
[单项选择]If a refrigeration crankcase compressor were short cycling on the low pressure cutout switch, the cause might be that the （）.
A. system was overcharged with refrigerant
B. system was low on refrigerant
C. suction valves were leaking slightly
D. relief valve was leaking slightly
[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]Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）
A. Sub-cooled liquid
B. Sub-cooled vapor
C. Superheated vapor
D. Liquid
[单项选择]A reciprocating air compressor is running roughly and vibrating excessively, indicating that the （）.
A. compressor is overloaded
B. motor is overloaded
C. foundation bolts are loose
D. belts are too tight
[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]Clearance gauges at bridges indicate （）.
A. the height of the tide
B. depth of water under the bridge
C. charted vertical clearance at mean low water
D. distance from the water to low steel of the bridge
