USCG Exam PracticeThermodynamics and heat exchangers
In a shell-and-tube heat exchanger, what is the primary purpose of the baffles installed in the shell?
- A. To prevent the tube bundle from expanding and buckling under thermal stress
- B. To separate the two fluid streams and prevent them from mixing
- ✓ To direct the shell-side fluid back and forth across the tube bundle, raising velocity and turbulenceCorrect
- D. To allow one tube sheet to float and accommodate thermal expansion
Why C is correct
DOE-HDBK-1018 Vol.1 §2-1 states that baffles in the shell direct the shell-side fluid back and forth across the bundle to raise velocity and turbulence, thereby improving heat transfer. Thermal expansion accommodation is handled by the floating tube sheet or U-bent tubes, not the baffles.
Cited:DOE-HDBK-1018 Vol.1 §2-1