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
- mfloat
Mass flow rate [kg/s]
- rhogfloat
Density of the gas [kg/m^3]
- rholfloat
Density of the liquid [kg/m^3]
- klfloat
Thermal conductivity of liquid [W/m/K]
- mulfloat
Viscosity of liquid [Pa*s]
- Cplfloat
Constant-pressure heat capacity of liquid [J/kg/K]
- Dfloat
Diameter of the tubing [m]
- xfloat
Quality at the specific interval [-]
- Returns
- hfloat
Heat transfer coefficient [W/m^2/K]
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
- mfloat
Mass flow rate [kg/s]
- rhogfloat
Density of the gas [kg/m^3]
- rholfloat
Density of the liquid [kg/m^3]
- klfloat
Thermal conductivity of liquid [W/m/K]
- mulfloat
Viscosity of liquid [Pa*s]
- Cplfloat
Constant-pressure heat capacity of liquid [J/kg/K]
- Dfloat
Diameter of the tubing [m]
- xfloat
Quality at the specific interval [-]
- Returns
- hfloat
Heat transfer coefficient [W/m^2/K]
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
- mfloat
Mass flow rate [kg/s]
- xfloat
Quality at the specific interval [-]
- Dfloat
Diameter of the channel [m]
- rholfloat
Density of the liquid [kg/m^3]
- rhogfloat
Density of the gas [kg/m^3]
- mulfloat
Viscosity of liquid [Pa*s]
- mugfloat
Viscosity of gas [Pa*s]
- klfloat
Thermal conductivity of liquid [W/m/K]
- Cplfloat
Constant-pressure heat capacity of liquid [J/kg/K]
- Returns
- hfloat
Heat transfer coefficient [W/m^2/K]
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
Balcılar, Muhammet, Ahmet Selim Dalkılıç, 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
- Tsatfloat
Saturation temperature at operating pressure [Pa]
- Twfloat
Wall temperature, [K]
- rhogfloat
Density of the gas [kg/m^3]
- rholfloat
Density of the liquid [kg/m^3]
- klfloat
Thermal conductivity of liquid [W/m/K]
- mulfloat
Viscosity of liquid [Pa*s]
- Hvapfloat
Heat of vaporization of the fluid at P, [J/kg]
- Lfloat
Length of the plate [m]
- anglefloat, optional
Angle of inclination of the plate [degrees]
- Returns
- hfloat
Heat transfer coefficient [W/m^2/K]
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
- mfloat
Mass flow rate [kg/s]
- xfloat
Quality at the specific interval [-]
- Dfloat
Diameter of the channel [m]
- rholfloat
Density of the liquid [kg/m^3]
- mulfloat
Viscosity of liquid [Pa*s]
- klfloat
Thermal conductivity of liquid [W/m/K]
- Cplfloat
Constant-pressure heat capacity of liquid [J/kg/K]
- Pfloat
Pressure of the fluid, [Pa]
- Pcfloat
Critical pressure of the fluid, [Pa]
- Returns
- hfloat
Heat transfer coefficient [W/m^2/K]
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
- Tfloat
Vapor temperature, [K]
- Pfloat
Vapor pressure, [Pa]
- MWfloat
Molecular weight of the gas, [g/mol]
- Hvapfloat
Heat of vaporization of the fluid at P, [J/kg]
- ffloat
Correction factor, [-]
- Returns
- hfloat
Heat transfer coefficient [W/m^2/K]
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