Question 348Motor Plants - Assistant Engineer

70% to pass

What occurs within the tubes of the device labeled "23" shown in the illustration? Illustration MO-0111

Diagram for USCG Motor Plants Assistant: What occurs within the tubes of the device labeled "23" shown in the...
AThe feedwater flowing through the inside of the tubes is being heated by the jacket water on the outside of the tubes.
BThe heat from the jacket water passing within the tubes is being transferred to the feedwater on the outside of the tubes.
CThe heat of combustion from the engine is being transferred azeotropically, adding latent heat to the entering jacket water.
DThe heat being transferred is subliminal; therefore expansion is taking place within the tubes.
AI Explanation

The correct answer is A) The feedwater flowing through the inside of the tubes is being heated by the jacket water on the outside of the tubes. This is the correct answer because the device labeled "23" in the illustration is likely a heat exchanger, where the jacket water from the engine is used to heat the feedwater before it enters the boiler. The heat from the jacket water passing on the outside of the tubes is transferred to the feedwater flowing through the inside of the tubes, increasing the temperature of the feedwater before it enters the boiler. The other answer choices are incorrect because B) describes the opposite heat transfer, C) refers to an azeotropic process which is not relevant here, and D) mentions subliminal heat transfer, which is not a real physical phenomenon.

Want to practice with timed exams?

Download Coast Guard Exams for the full exam experience.

Get the App