NTU_FROM_P_PLATE

This function solves side-1 transfer units for multipass plate exchangers from effectiveness, capacity ratio, and pass arrangement settings. It captures both overall flow direction and pass-level direction effects.

The inversion can be written as \mathrm{NTU}_1 = f^{-1}(P_1, R_1, N_{p1}, N_{p2}, \text{flow flags}).

Excel Usage

=NTU_FROM_P_PLATE(p_one, r_one, np_one, np_two, counterflow, passes_counterflow, reverse)

• p_one (float, required): Thermal effectiveness with respect to stream 1 (-).
• r_one (float, required): Heat capacity ratio with respect to stream 1 (-).
• np_one (int, required): Number of passes on side 1 (-).
• np_two (int, required): Number of passes on side 2 (-).
• counterflow (bool, optional, default: true): Overall flow is counterflow when true (-).
• passes_counterflow (bool, optional, default: true): Individual passes are counterflow when true (-).
• reverse (bool, optional, default: false): Reverse pass order for internal compatibility (-).

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

Example 1: NTU for 3 pass by 1 pass plate exchanger

Inputs:

p_one	r_one	np_one	np_two
0.5743	0.3333333333	3	1

Excel formula:

=NTU_FROM_P_PLATE(0.5743, 0.3333333333, 3, 1)

Expected output:

0.999834

Example 2: NTU for 1 pass parallel plate exchanger

Inputs:

p_one	r_one	np_one	np_two	counterflow	passes_counterflow
0.5	0.8	1	1	false	false

Excel formula:

=NTU_FROM_P_PLATE(0.5, 0.8, 1, 1, FALSE, FALSE)

Expected output:

1.27921

Example 3: NTU for 2 pass by 2 pass counterflow

Inputs:

p_one	r_one	np_one	np_two
0.6	0.4	2	2

Excel formula:

=NTU_FROM_P_PLATE(0.6, 0.4, 2, 2)

Expected output:

1.06976

Example 4: NTU for 1 pass by 2 pass plate exchanger

Inputs:

p_one	r_one	np_one	np_two
0.55	0.6	1	2

Excel formula:

=NTU_FROM_P_PLATE(0.55, 0.6, 1, 2)

Expected output:

1.1016

Python Code

Show Code

from ht.hx import NTU_from_P_plate as hx_NTU_from_P_plate

def NTU_from_P_plate(p_one, r_one, np_one, np_two, counterflow=True, passes_counterflow=True, reverse=False):
    """
    Solve NTU for a plate 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 (-).
        np_one (int): Number of passes on side 1 (-).
        np_two (int): Number of passes on side 2 (-).
        counterflow (bool, optional): Overall flow is counterflow when true (-). Default is True.
        passes_counterflow (bool, optional): Individual passes are counterflow when true (-). Default is True.
        reverse (bool, optional): Reverse pass order for internal compatibility (-). Default is False.

    Returns:
        float: Thermal number of transfer units with respect to stream 1 (-).
    """
    try:
        result = hx_NTU_from_P_plate(P1=p_one, R1=r_one, Np1=np_one, Np2=np_two, counterflow=counterflow, passes_counterflow=passes_counterflow, reverse=reverse)
        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 (-).

np_one *

Number of passes on side 1 (-).

np_two *

Number of passes on side 2 (-).

counterflow

Overall flow is counterflow when true (-).

passes_counterflow

Individual passes are counterflow when true (-).

reverse

Reverse pass order for internal compatibility (-).