BOYKO_KRUZHILIN

This function computes the condensation heat transfer coefficient in tubes using the Boyko-Kruzhilin method. The model starts from a liquid-only convective coefficient and scales it by a two-phase density/quality correction.

The core relation is:

h_{TP} = h_{LO}\left[1 + x\left(\frac{\rho_l}{\rho_g} - 1\right)\right]^{1/2}

where h_{LO} is evaluated from a turbulent single-phase style correlation. The output is a scalar heat transfer coefficient in W/m^2/K.

Excel Usage

=BOYKO_KRUZHILIN(m, rhog, rhol, kl, mul, Cpl, D, x)

m (float, required): Mass flow rate (kg/s).
rhog (float, required): Gas density (kg/m^3).
rhol (float, required): Liquid density (kg/m^3).
kl (float, required): Liquid thermal conductivity (W/m/K).
mul (float, required): Liquid viscosity (Pa*s).
Cpl (float, required): Liquid heat capacity at constant pressure (J/kg/K).
D (float, required): Tube diameter (m).
x (float, required): Quality at the specific interval (-).

Returns (float): Heat transfer coefficient (W/m^2/K).

Example 1: Example values from reference

Inputs:

m	rhog	rhol	kl	mul	Cpl	D	x
0.3534291735	6.36	582.9	0.098	0.000159	2520	0.03	0.85

Excel formula:

=BOYKO_KRUZHILIN(0.3534291735, 6.36, 582.9, 0.098, 0.000159, 2520, 0.03, 0.85)

Expected output:

10598.7

Example 2: Low quality vapor fraction

Inputs:

m	rhog	rhol	kl	mul	Cpl	D	x
0.15	9	900	0.12	0.00021	2300	0.02	0.1

Excel formula:

=BOYKO_KRUZHILIN(0.15, 9, 900, 0.12, 0.00021, 2300, 0.02, 0.1)

Expected output:

4030.28

Example 3: Mid quality vapor fraction

Inputs:

m	rhog	rhol	kl	mul	Cpl	D	x
0.6	4.5	700	0.095	0.00017	2400	0.025	0.5

Excel formula:

=BOYKO_KRUZHILIN(0.6, 4.5, 700, 0.095, 0.00017, 2400, 0.025, 0.5)

Expected output:

21121.4

Example 4: Higher mass flow rate

Inputs:

m	rhog	rhol	kl	mul	Cpl	D	x
1.2	7.5	650	0.11	0.00019	2150	0.04	0.7

Excel formula:

=BOYKO_KRUZHILIN(1.2, 7.5, 650, 0.11, 0.00019, 2150, 0.04, 0.7)

Expected output:

13859.1

Python Code

Show Code

from ht.condensation import Boyko_Kruzhilin as ht_Boyko_Kruzhilin

def Boyko_Kruzhilin(m, rhog, rhol, kl, mul, Cpl, D, x):
    """
    Calculate condensation heat transfer coefficient using the Boyko-Kruzhilin correlation.

    See: https://ht.readthedocs.io/en/latest/ht.condensation.html

    This example function is provided as-is without any representation of accuracy.

    Args:
        m (float): Mass flow rate (kg/s).
        rhog (float): Gas density (kg/m^3).
        rhol (float): Liquid density (kg/m^3).
        kl (float): Liquid thermal conductivity (W/m/K).
        mul (float): Liquid viscosity (Pa*s).
        Cpl (float): Liquid heat capacity at constant pressure (J/kg/K).
        D (float): Tube diameter (m).
        x (float): Quality at the specific interval (-).

    Returns:
        float: Heat transfer coefficient (W/m^2/K).
    """
    try:
        result = ht_Boyko_Kruzhilin(m=m, rhog=rhog, rhol=rhol, kl=kl, mul=mul, Cpl=Cpl, D=D, x=x)
        return result
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

m *

Mass flow rate (kg/s).

rhog *

Gas density (kg/m^3).

rhol *

Liquid density (kg/m^3).

kl *

Liquid thermal conductivity (W/m/K).

mul *

Liquid viscosity (Pa*s).

Cpl *

Liquid heat capacity at constant pressure (J/kg/K).

D *

Tube diameter (m).

x *

Quality at the specific interval (-).