MATH 3A03 Lecture Notes - Lecture 11: Heat Transfer Coefficient, Fouling, Logarithmic Mean Temperature Difference
12 Oct 2016
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Document Summary
Heat exchangers are one of the most common unit operations used in industry and are used to transfer heat between two fluids for the purpose of: recovering thermal energy, transferring heat to a closed-loop process, maintaining reaction stability. Example: air conditioner: two horizontal, continuous finned heat exchangers (evaporator and condenser) one sits inside your house while the other sits outside the house. Heat exchangers are classified by: type of construction, cross-flow (single pass): bank of tubes. Fluid: outside baffles or fins may be present to increase heat transfer and control mixing. One tube inside an outer tube (annular tubes: cheapest but least effective, shell-and tube (multiple pipe): Multiple tubes inside an outer tube ( shell ) or multiple outer tubes (multishell: baffles often installed to increase turbulence (! increase h) and physically support tubes in the shell to prevent vibrations, multiple passes possible.
