Heat transfer and pressure drop across tube bundles (ht.conv_tube_bank)¶

ht.conv_tube_bank.
dP_Kern
(m, rho, mu, DShell, LSpacing, pitch, Do, NBaffles, mu_w=None)[source]¶ Calculates pressure drop for crossflow across a tube bank according to the equivalentdiameter method developed by Kern [1], presented in [2].
\[ \begin{align}\begin{aligned}\Delta P = \frac{f (m/S_s)^2 D_s(N_B+1)}{2\rho D_e(\mu/\mu_w)^{0.14}}\\S_S = \frac{D_S (P_TD_o) L_B}{P_T}\\D_e = \frac{4(P_T^2  \pi D_o^2/4)}{\pi D_o}\end{aligned}\end{align} \]Parameters:  m : float
Mass flow rate, [kg/s]
 rho : float
Fluid density, [kg/m^3]
 mu : float
Fluid viscosity, [Pa*s]
 DShell : float
Diameter of exchanger shell, [m]
 LSpacing : float
Baffle spacing, [m]
 pitch : float
Tube pitch, [m]
 Do : float
Tube outer diameter, [m]
 NBaffles : float
Baffle count, []
 mu_w : float
Fluid viscosity at wall temperature, [Pa*s]
Returns:  dP : float
Pressure drop across bundle, [Pa]
Notes
Adjustment for viscosity left out of this function. Example is from [2]. Roughly 10% difference due to reading of graph. Graph scanned from [1], and interpolation is used to read it.
References
[1] (1, 2, 3) Kern, Donald Quentin. Process Heat Transfer. McGrawHill, 1950. [2] (1, 2, 3) Peters, Max, Klaus Timmerhaus, and Ronald West. Plant Design and Economics for Chemical Engineers. 5E. New York: McGrawHill, 2002. Examples
>>> dP_Kern(m=11., rho=995., mu=0.000803, mu_w=0.000657, DShell=0.584, ... LSpacing=0.1524, pitch=0.0254, Do=.019, NBaffles=22) 18980.58768759033

ht.conv_tube_bank.
dP_Zukauskas
(Re, n, ST, SL, D, rho, Vmax)[source]¶ Calculates pressure drop for crossflow across a tube bank of tube number n at a specified Re. Method presented in [1]. Also presented in [2].
\[\Delta P = N_L \chi \left(\frac{\rho V_{max}^2}{2}\right)f\]Parameters:  Re : float
Reynolds number, []
 n : float
Number of tube rows, []
 ST : float
Transverse pitch, used only by some conditions, [m]
 SL : float
Longitudal pitch, used only by some conditions, [m]
 D : float
Tube outer diameter, [m]
 rho : float
Fluid density, [kg/m^3]
 Vmax : float
Maximum velocity, [m/s]
Returns:  dP : float
Pressure drop, [Pa]
Notes
Does not account for effects in a heat exchanger. Example 2 is from [2]. Matches to 0.3%; figures are very approximate. Interpolation used with 4 graphs to obtain friction factor and a correction factor.
References
[1] (1, 2) Zukauskas, A. Heat transfer from tubes in crossflow. In T.F. Irvine, Jr. and J. P. Hartnett, editors, Advances in Heat Transfer, volume 8, pages 93160. Academic Press, Inc., New York, 1972. [2] (1, 2, 3) Bergman, Theodore L., Adrienne S. Lavine, Frank P. Incropera, and David P. DeWitt. Introduction to Heat Transfer. 6E. Hoboken, NJ: Wiley, 2011. Examples
>>> dP_Zukauskas(Re=13943., n=7, ST=0.0313, SL=0.0343, D=0.0164, rho=1.217, Vmax=12.6) 235.22916169118335 >>> dP_Zukauskas(Re=13943., n=7, ST=0.0313, SL=0.0313, D=0.0164, rho=1.217, Vmax=12.6) 217.0750033117563