NTU_FROM_P_E

This function computes side-1 transfer units for a TEMA E shell-and-tube exchanger from specified side-1 effectiveness, capacity ratio, and tube-pass configuration. It supports optimal and non-optimal pass arrangement where applicable.

The target is \mathrm{NTU}_1 = f^{-1}(P_1, R_1, N_{tp}, \text{optimal}).

Excel Usage

=NTU_FROM_P_E(p_one, r_one, ntp, optimal)

• p_one (float, required): Thermal effectiveness with respect to stream 1 (-).
• r_one (float, required): Heat capacity ratio with respect to stream 1 (-).
• ntp (int, required): Number of tube passes (-).
• optimal (bool, optional, default: true): Use optimal pass arrangement when applicable (-).

Returns (float): Thermal number of transfer units with respect to stream 1 (-).

Example 1: NTU for TEMA E with two passes

Inputs:

p_one	r_one	ntp
0.58	0.3333333333	2

Excel formula:

=NTU_FROM_P_E(0.58, 0.3333333333, 2)

Expected output:

1.0382

Example 2: NTU for TEMA E single pass

Inputs:

p_one	r_one	ntp
0.6	0.4	1

Excel formula:

=NTU_FROM_P_E(0.6, 0.4, 1)

Expected output:

1.06976

Example 3: NTU for TEMA E four passes

Inputs:

p_one	r_one	ntp
0.55	0.25	4

Excel formula:

=NTU_FROM_P_E(0.55, 0.25, 4)

Expected output:

0.897043

Example 4: NTU for TEMA E three passes inefficient

Inputs:

p_one	r_one	ntp	optimal
0.52	0.5	3	false

Excel formula:

=NTU_FROM_P_E(0.52, 0.5, 3, FALSE)

Expected output:

0.919954

Python Code

Show Code

from ht.hx import NTU_from_P_E as hx_NTU_from_P_E

def NTU_from_P_E(p_one, r_one, ntp, optimal=True):
    """
    Solve NTU for a TEMA E exchanger from effectiveness and capacity ratio.

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

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

    Args:
        p_one (float): Thermal effectiveness with respect to stream 1 (-).
        r_one (float): Heat capacity ratio with respect to stream 1 (-).
        ntp (int): Number of tube passes (-).
        optimal (bool, optional): Use optimal pass arrangement when applicable (-). Default is True.

    Returns:
        float: Thermal number of transfer units with respect to stream 1 (-).
    """
    try:
        result = hx_NTU_from_P_E(P1=p_one, R1=r_one, Ntp=ntp, optimal=optimal)
        return result
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

p_one *

Thermal effectiveness with respect to stream 1 (-).

r_one *

Heat capacity ratio with respect to stream 1 (-).

ntp *

Number of tube passes (-).

optimal

Use optimal pass arrangement when applicable (-).