A. out Heat Exchangers bin(shell side) Example: Shell and tube A,in(tube side) Cross-counter Flow B out Two basic methods discussed 1. LMTD Method q=UA AT UAAT △T LMTD n △T 2. 8-NTU Method 9=8 q max O max 8 c min h ic, where: g max min UA f(NTU, Cr) NTU overall HX mIn max Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 11 Heat Exchangers • Two basic methods discussed: 1. LMTD Method 2. -NTU Method TB,out (shell side) TB,in (tube side) TA,in TA,out Example: Shell and Tube: Cross-counter Flow LMTD i o out in UA T T T T T q UA =     −  = ln ( ) q C Th i Tc i or q q min , , max : = − =   ( ) where q C Th i Tc i q q max min , , max : = −  = min , NTU C UAoverall HX = ( ) NTU Cr  = f , C (C 1) r max min r =  C C