NTUBES_HEDH

This function estimates tube count from bundle geometry using the HEDH approximation for standard layout angles. It provides a fast, approximate tube-count calculation for conceptual exchanger sizing.

The correlation is of the form N \approx \frac{0.78\,(D_{bundle}-D_o)^2}{C_1 p^2}.

Excel Usage

=NTUBES_HEDH(DBundle, Do, pitch, angle)

DBundle (float, required): Outer diameter of tube bundle (m).
Do (float, required): Tube outer diameter (m).
pitch (float, required): Tube pitch (m).
angle (int, optional, default: 30): Tube layout angle (degrees).

Returns (int): Estimated number of tubes (-).

Example 1: HEDH tube count example

Inputs:

DBundle	Do	pitch	angle
1.184	0.028	0.036	30

Excel formula:

=NTUBES_HEDH(1.184, 0.028, 0.036, 30)

Expected output:

928

Example 2: HEDH tube count with 90 degree layout

Inputs:

DBundle	Do	pitch	angle
1	0.025	0.03125	90

Excel formula:

=NTUBES_HEDH(1, 0.025, 0.03125, 90)

Expected output:

759

Example 3: HEDH tube count for small bundle

Inputs:

DBundle	Do	pitch	angle
0.6	0.01905	0.025	45

Excel formula:

=NTUBES_HEDH(0.6, 0.01905, 0.025, 45)

Expected output:

421

Example 4: HEDH tube count for larger bundle

Inputs:

DBundle	Do	pitch	angle
1.5	0.028	0.036	60

Excel formula:

=NTUBES_HEDH(1.5, 0.028, 0.036, 60)

Expected output:

1504

Python Code

Show Code

from ht.hx import Ntubes_HEDH as hx_Ntubes_HEDH

def Ntubes_HEDH(DBundle, Do, pitch, angle=30):
    """
    Estimate tube count from bundle diameter using the HEDH correlation.

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

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

    Args:
        DBundle (float): Outer diameter of tube bundle (m).
        Do (float): Tube outer diameter (m).
        pitch (float): Tube pitch (m).
        angle (int, optional): Tube layout angle (degrees). Default is 30.

    Returns:
        int: Estimated number of tubes (-).
    """
    try:
        result = hx_Ntubes_HEDH(DBundle=DBundle, Do=Do, pitch=pitch, angle=angle)
        return int(result)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

DBundle *

Outer diameter of tube bundle (m).

Do *

Tube outer diameter (m).

pitch *

Tube pitch (m).

angle

Tube layout angle (degrees).