Condensation (ht.condensation)¶
- ht.condensation.Akers_Deans_Crosser(m, rhog, rhol, kl, mul, Cpl, D, x)[source]¶
Calculates heat transfer coefficient for condensation of a pure chemical inside a vertical tube or tube bundle, as presented in [2] according to [1].
$Nu = \frac{hD_i}{k_l} = C Re_e^n Pr_l^{1/3}$$C = 0.0265, n=0.8 \text{ for } Re_e > 5\times10^4$$C = 5.03, n=\frac{1}{3} \text{ for } Re_e < 5\times10^4$$Re_e = \frac{D_i G_e}{\mu_l}$$G_e = G\left[(1-x)+x(\rho_l/\rho_g)^{0.5}\right]$- Parameters
- m
float
Mass flow rate [kg/s]
- rhog
float
Density of the gas [kg/m^3]
- rhol
float
Density of the liquid [kg/m^3]
- kl
float
Thermal conductivity of liquid [W/m/K]
- mul
float
Viscosity of liquid [Pa*s]
- Cpl
float
Constant-pressure heat capacity of liquid [J/kg/K]
- D
float
Diameter of the tubing [m]
- x
float
Quality at the specific interval [-]
- m
- Returns
- h
float
Heat transfer coefficient [W/m^2/K]
- h
References
- 1
Akers, W. W., H. A. Deans, and O. K. Crosser. “Condensing Heat Transfer Within Horizontal Tubes.” Chem. Eng. Progr. Vol: 55, Symposium Ser. No. 29 (January 1, 1959).
- 2
Kakaç, Sadik, ed. Boilers, Evaporators, and Condensers. 1st. Wiley-Interscience, 1991.
Examples
>>> Akers_Deans_Crosser(m=0.35, rhog=6.36, rhol=582.9, kl=0.098, ... mul=159E-6, Cpl=2520., D=0.03, x=0.85) 7117.24177265201
- ht.condensation.Boyko_Kruzhilin(m, rhog, rhol, kl, mul, Cpl, D, x)[source]¶
Calculates heat transfer coefficient for condensation of a pure chemical inside a vertical tube or tube bundle, as presented in [2] according to [1].
$h_f = h_{LO}\left[1 + x\left(\frac{\rho_L}{\rho_G} - 1\right)\right]^{0.5}$$h_{LO} = 0.021 \frac{k_L}{L} Re_{LO}^{0.8} Pr^{0.43}$- Parameters
- m
float
Mass flow rate [kg/s]
- rhog
float
Density of the gas [kg/m^3]
- rhol
float
Density of the liquid [kg/m^3]
- kl
float
Thermal conductivity of liquid [W/m/K]
- mul
float
Viscosity of liquid [Pa*s]
- Cpl
float
Constant-pressure heat capacity of liquid [J/kg/K]
- D
float
Diameter of the tubing [m]
- x
float
Quality at the specific interval [-]
- m
- Returns
- h
float
Heat transfer coefficient [W/m^2/K]
- h
Notes
To calculate overall heat transfer coefficient during condensation, simply average values at x = 1 and x = 0.
References
- 1
Boyko, L. D., and G. N. Kruzhilin. “Heat Transfer and Hydraulic Resistance during Condensation of Steam in a Horizontal Tube and in a Bundle of Tubes.” International Journal of Heat and Mass Transfer 10, no. 3 (March 1, 1967): 361-73. doi:10.1016/0017-9310(67)90152-4.
- 2(1,2)
Hewitt, G. L. Shires T. Reg Bott G. F., George L. Shires, and T. R. Bott. Process Heat Transfer. 1E. Boca Raton: CRC Press, 1994.
Examples
Page 589 in [2], matches exactly.
>>> Boyko_Kruzhilin(m=500*pi/4*.03**2, rhog=6.36, rhol=582.9, kl=0.098, ... mul=159E-6, Cpl=2520., D=0.03, x=0.85) 10598.657227479956
- ht.condensation.Cavallini_Smith_Zecchin(m, x, D, rhol, rhog, mul, mug, kl, Cpl)[source]¶
Calculates heat transfer coefficient for condensation of a fluid inside a tube, as presented in [1], also given in [2] and [3].
$Nu = \frac{hD_i}{k_l} = 0.05 Re_e^{0.8} Pr_l^{0.33}$$Re_{eq} = Re_g(\mu_g/\mu_l)(\rho_l/\rho_g)^{0.5} + Re_l$$v_{gs} = \frac{mx}{\rho_g \frac{\pi}{4}D^2}$$v_{ls} = \frac{m(1-x)}{\rho_l \frac{\pi}{4}D^2}$- Parameters
- m
float
Mass flow rate [kg/s]
- x
float
Quality at the specific interval [-]
- D
float
Diameter of the channel [m]
- rhol
float
Density of the liquid [kg/m^3]
- rhog
float
Density of the gas [kg/m^3]
- mul
float
Viscosity of liquid [Pa*s]
- mug
float
Viscosity of gas [Pa*s]
- kl
float
Thermal conductivity of liquid [W/m/K]
- Cpl
float
Constant-pressure heat capacity of liquid [J/kg/K]
- m
- Returns
- h
float
Heat transfer coefficient [W/m^2/K]
- h
References
- 1
A. Cavallini, J. R. Smith and R. Zecchin, A dimensionless correlation for heat transfer in forced convection condensation, 6th International Heat Transfer Conference., Tokyo, Japan (1974) 309-313.
- 2
Kakaç, Sadik, ed. Boilers, Evaporators, and Condensers. 1st. Wiley-Interscience, 1991.
- 3
Balcilar, Muhammet, Ahmet Selim Dalkiliç, Berna Bolat, and Somchai Wongwises. “Investigation of Empirical Correlations on the Determination of Condensation Heat Transfer Characteristics during Downward Annular Flow of R134a inside a Vertical Smooth Tube Using Artificial Intelligence Algorithms.” Journal of Mechanical Science and Technology 25, no. 10 (October 12, 2011): 2683-2701. doi:10.1007/s12206-011-0618-2.
Examples
>>> Cavallini_Smith_Zecchin(m=1, x=0.4, D=.3, rhol=800, rhog=2.5, mul=1E-5, mug=1E-3, kl=0.6, Cpl=2300) 5578.218369177804
- ht.condensation.Nusselt_laminar(Tsat, Tw, rhog, rhol, kl, mul, Hvap, L, angle=90.0)[source]¶
Calculates heat transfer coefficient for laminar film condensation of a pure chemical on a flat plate, as presented in [1] according to an analysis performed by Nusselt in 1916.
$h=0.943\left[\frac{g\sin(\theta)\rho_{liq}(\rho_l-\rho_v)k_{l}^3 \Delta H_{vap}}{\mu_l(T_{sat}-T_w)L}\right]^{0.25}$- Parameters
- Tsat
float
Saturation temperature at operating pressure [Pa]
- Tw
float
Wall temperature, [K]
- rhog
float
Density of the gas [kg/m^3]
- rhol
float
Density of the liquid [kg/m^3]
- kl
float
Thermal conductivity of liquid [W/m/K]
- mul
float
Viscosity of liquid [Pa*s]
- Hvap
float
Heat of vaporization of the fluid at P, [J/kg]
- L
float
Length of the plate [m]
- angle
float
,optional
Angle of inclination of the plate [degrees]
- Tsat
- Returns
- h
float
Heat transfer coefficient [W/m^2/K]
- h
Notes
Optionally, the plate may be inclined. The constant 0.943 is actually:
$2\sqrt{2}/3$References
- 1(1,2)
Hewitt, G. L. Shires T. Reg Bott G. F., George L. Shires, and T. R. Bott. Process Heat Transfer. 1E. Boca Raton: CRC Press, 1994.
Examples
578 in [1], matches exactly.
>>> Nusselt_laminar(Tsat=370, Tw=350, rhog=7.0, rhol=585., kl=0.091, ... mul=158.9E-6, Hvap=776900, L=0.1) 1482.206403453679
- ht.condensation.Shah(m, x, D, rhol, mul, kl, Cpl, P, Pc)[source]¶
Calculates heat transfer coefficient for condensation of a fluid inside a tube, as presented in [1] and again by the same author in [2]; also given in [3]. Requires no properties of the gas. Uses the Dittus-Boelter correlation for single phase heat transfer coefficient, with a Reynolds number assuming all the flow is liquid.
$h_{TP} = h_L\left[(1-x)^{0.8} +\frac{3.8x^{0.76}(1-x)^{0.04}} {P_r^{0.38}}\right]$- Parameters
- m
float
Mass flow rate [kg/s]
- x
float
Quality at the specific interval [-]
- D
float
Diameter of the channel [m]
- rhol
float
Density of the liquid [kg/m^3]
- mul
float
Viscosity of liquid [Pa*s]
- kl
float
Thermal conductivity of liquid [W/m/K]
- Cpl
float
Constant-pressure heat capacity of liquid [J/kg/K]
- P
float
Pressure of the fluid, [Pa]
- Pc
float
Critical pressure of the fluid, [Pa]
- m
- Returns
- h
float
Heat transfer coefficient [W/m^2/K]
- h
Notes
[1] is well written an unambiguous as to how to apply this equation.
References
- 1(1,2)
Shah, M. M. “A General Correlation for Heat Transfer during Film Condensation inside Pipes.” International Journal of Heat and Mass Transfer 22, no. 4 (April 1, 1979): 547-56. doi:10.1016/0017-9310(79)90058-9.
- 2
Shah, M. M., Heat Transfer During Film Condensation in Tubes and Annuli: A Review of the Literature, ASHRAE Transactions, vol. 87, no. 3, pp. 1086-1100, 1981.
- 3
Kakaç, Sadik, ed. Boilers, Evaporators, and Condensers. 1st. Wiley-Interscience, 1991.
Examples
>>> Shah(m=1, x=0.4, D=.3, rhol=800, mul=1E-5, kl=0.6, Cpl=2300, P=1E6, Pc=2E7) 2561.2593415479214
- ht.condensation.h_kinetic(T, P, MW, Hvap, f=1.0)[source]¶
Calculates heat transfer coefficient for condensation of a pure chemical inside a vertical tube or tube bundle, as presented in [2] according to [1].
$h = \left(\frac{2f}{2-f}\right)\left(\frac{MW}{1000\cdot 2\pi R T} \right)^{0.5}\left(\frac{H_{vap}^2 P \cdot MW}{1000\cdot RT^2}\right)$- Parameters
- Returns
- h
float
Heat transfer coefficient [W/m^2/K]
- h
Notes
f is a correction factor for how the removal of gas particles affects the behavior of the ideal gas in diffusing to the condensing surface. It is quite close to one, and has not been well explored in the literature due to the rarity of the importance of the kinetic resistance.
References
- 1
Berman, L. D. “On the Effect of Molecular-Kinetic Resistance upon Heat Transfer with Condensation.” International Journal of Heat and Mass Transfer 10, no. 10 (October 1, 1967): 1463. doi:10.1016/0017-9310(67)90033-6.
- 2
Kakaç, Sadik, ed. Boilers, Evaporators, and Condensers. 1 edition. Wiley-Interscience, 1991.
- 3
Stephan, Karl. Heat Transfer in Condensation and Boiling. Translated by C. V. Green. Softcover reprint of the original 1st ed. 1992 edition. Berlin; New York: Springer, 2013.
Examples
Water at 1 bar and 300 K:
>>> h_kinetic(300, 1E5, 18.02, 2441674) 30788829.908851154