Contents - Index


Finned circular tubes geometry

 

 

The procedure: 

 

CHX_geom_finned_circular_tube(TypeHX$: D_tube, D_fin, S_T, S_L, fin_pitch, fin_thk, D_h, sigma, alpha, A_fin\A)

 

Provides the geometric data associated with a finned circular tube compact heat exchanger surface.  These data are from Kays and London (1994).

 

Inputs:

The only input is the string identifying the geometry TypeHX$

CF-7.34 : 'fc_tubes_scf-734'  

CF-8.72 : 'fc_tubes_scf-872'  

CF-8.72(c) : 'fc_tubes_scf-872c'  

CF-7.0-5/8j : 'fc_tubes_scf-70-58j'  

CF-8.7-5/8j(a) : 'fc_tubes_scf-87-58ja'  

CF-8.7-5/8j(b) : 'fc_tubes_scf-87-58jb'  

CF-9.05-3/4j(a) : 'fc_tubes_scf-905-34ja'  

CF-9.05-3/4j(b) : 'fc_tubes_scf-905-34jb'  

CF-9.05-3/4j(c) : 'fc_tubes_scf-905-34jc'  

CF-9.05-3/4j(d) : 'fc_tubes_scf-905-34jd'  

CF-9.05-3/4j(e) : 'fc_tubes_scf-905-34je'  

CF-8.8-1.0j(a) : 'fc_tubes_scf-88-10ja'  

CF-8.8-1.0j(b) : 'fc_tubes_scf-88-10jb'  

 

Outputs:

D_tube = tube outer diameter (m or ft)

D_fin = fin outer diameter (m or ft)

S_T = transverse tube spacing (m or ft)

S_L = longitudinal tube spacing (m or ft)

fin_pitch = # fins per length (fins/m or fins/ft)

fin_thk = fin thickness (m or ft)

D_h = hydraulic diameter defined as 4 x minimum flow area x length/heat transfer area (m or ft)

sigma = minimum flow area/frontal area

alpha = heat transfer area/volume (m^2/m^3 or ft^2/ft^3)

A_fin\A = heat transfer area on fins/heat transfer area

 

Example

$UnitSystem SI Mass j K Pa

TypeHX$='fc_tubes_scf-88-10ja' 

Call chx_geom_finned_circular_tube(TypeHX$: D_tube, D_fin, S_T, S_L, fin_pitch, fin_thk, D_h, sigma, alpha, A_fin\A)

 

 

{Solution is:

D_tube = 0.026 [m]

D_fin = 0.0441 [m]

S_T = 0.0498 [m]

S_L = 0.0524 [m]

fin_pitch = 346.5 [1/m]

fin_thk = 0.00031 [m]

D_h = 0.00598 [m]

sigma = 0.439

alpha = 299 [m^2/m^3]

A_fin\A = 0.825}

 

Related procedures include:

Nondimensional Functions

Coefficient of Heat Transfer

Pressure Drop