N-2N TEMA E Shell and Tube
A shell and tube heat exchanger consists of an outer shell filled with a tube bank. The shell side fluid flows in the shell, around the tube, while the tube side fluid flows through the tubes. There are many shell and tube configurations characterized by, among other things, the shell type and the number and configuration of the shell and tube flows. An N-2N TEMA E shell and tube heat exchanger has an E type shell in which the shell side fluid enters at one end and leaves at the other. It consists of N shell passes and 2xN tube passes. The effectiveness-NTU and Log Mean Temperature Difference solutions are both available for 2-4 TEMA E shell and tube heat exchangers. Solution is from Nellis and Klein.
Example 1:
$UnitSystem SI Mass J K Pa
$VarInfo UA C_dot_1 C_dot_1 C_dot_min Units = 'W/K'
$VarInfo epsilon NTU Units = '-'
UA = 75 [W/K]
C_dot_1 = 50 [W/K]
C_dot_2 = 30 [W/K]
C_dot_min = Min(C_dot_1,C_dot_2)
NTU = UA/C_dot_min
epsilon=hx('shell&tube_6', Ntu, C_dot_1, C_dot_2, 'epsilon')
{Solution:
epsilon = 0.8070}
Example 2:
$UnitSystem SI Mass J K Pa
$VarInfo UA C_dot_1 C_dot_1 C_dot_min Units = 'W/K'
$VarInfo epsilon NTU Units = '-'
C_dot_1 = 50 [W/K]
C_dot_2 = 30 [W/K]
epsilon = 0.61
NTU=hx('shell&tube_8', epsilon, C_dot_1, C_dot_2, 'NTU')
C_dot_min = Min(C_dot_1,C_dot_2)
UA = NTU*C_dot_min
{Solution:
NTU = 1.218
UA = 36.53}