Which of the following is FALSE?____.
A: The most common cause of a localized hotspot is due to friction.
B: When the concentration of oil mist reaches about 13% oil mist (oxygen ratio), it is at its lower explosive limit.
C: Tests have shown that it is necessary for a temperature of more than 800C to ignite oil mist in a crankcase under operating conditions.
D: Many
causes including external fire may result in crankcase explosion.
A: The most common cause of a localized hotspot is due to friction.
B: When the concentration of oil mist reaches about 13% oil mist (oxygen ratio), it is at its lower explosive limit.
C: Tests have shown that it is necessary for a temperature of more than 800C to ignite oil mist in a crankcase under operating conditions.
D: Many
causes including external fire may result in crankcase explosion.
举一反三
- Which of the following is TRUE?____. A: If there is oxygen and fuel in an enclosed tank, there must be an explosion. B: Crankcase explosion is least likely to occur, because there is no air in crankcase. C: The droplets of lubricating oil splashing around in the crankcase is usually too large to start burning. D: The oil/air concentration in crankcase is usually too rich.
- In a normally operating diesel engine， the main cause of lubricating oil contamination in the crankcase is a result of the （）.
- _____ is used to detect faults in the cylinder. A: The cylinder condition monitoring system B: The oil mist density monitoring system C: The oil viscosity monitoring system D: The oil temperature monitoring system
- When fuel enters the crankcase of a diesel engine, it （） A: dilutes the lube oil and reduces its viscosity B: forms sulfuric acid in the lube oil C: causes pitting and failure of the bearings D: causes sludge deposits on valve stem
- Oil pan (see Fig.3-5) is a container mounted at the bottom of the crankcase which serves as engine oil storage．