# -*- coding: utf-8 -*-
'''Chemical Engineering Design Library (ChEDL). Utilities for process modeling.
Copyright (C) 2016, Caleb Bell <Caleb.Andrew.Bell@gmail.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.'''
from __future__ import division
from math import log
from collections import namedtuple
from scipy.interpolate import interp1d, interp2d
from scipy.constants import hp
import os
from io import open
from pprint import pprint
__all__ = ['VFD_efficiency', 'CSA_motor_efficiency', 'motor_efficiency_underloaded',
'Corripio_pump_efficiency', 'Corripio_motor_efficiency',
'specific_speed', 'specific_diameter', 'speed_synchronous', 'nema_sizes',
'nema_sizes_hp', 'motor_round_size', 'nema_min_P', 'nema_high_P', 'plug_types',
'voltages_1_phase_residential', 'voltages_3_phase', 'frequencies',
'residential_power', 'industrial_power', 'current_ideal',
'liquid_jet_pump']
folder = os.path.join(os.path.dirname(__file__), 'data')
[docs]def liquid_jet_pump(rhop, rhos, Km=.15, Kd=0.1, Ks=0.1, Kp=0.0,
d_nozzle=None, d_mixing=None, d_diffuser=None,
Qp=None, Qs=None, P1=None, P2=None, P5=None,
nozzle_retracted=True):
r'''Calculate the remaining variable in a liquid jet pump, using a model
presented in [1]_ as well as [2]_, [3]_, and [4]_.
.. math::
N = \frac{2R + \frac{2 C M^2 R^2}{1-R} - R^2 (1+CM) (1+M) (1 + K_m
+ K_d + \alpha^2) - \frac{CM^2R^2}{(1-R)^2} (1+K_s)}
{(1+K_p) - 2R - \frac{2CM^2R^2}{1-R} + R^2(1+CM)(1+M)(1+K_m + K_d
+ \alpha^2) + (1-j)\left(\frac{CM^2R^2}{({1-R})^2} \right)(1+K_s)}
\text{Pressure ratio} = N = \frac{P_5 - P_2}{P_1 - P_5}
\text{Volume flow ratio} = M = \frac{Q_s}{Q_p}
\text{Jet pump efficiency} = \eta = M\cdot N =
\frac{Q_s(P_5-P_2)}{Q_p(P_1 - P_5)}
R = \frac{A_n}{A_m}
C = \frac{\rho_s}{\rho_p}
Parameters
----------
rhop : float
The density of the primary (motive) fluid, [kg/m^3]
rhos : float
The density of the secondary fluid (drawn from the vacuum chamber),
[kg/m^3]
Km : float, optional
The mixing chamber loss coefficient, [-]
Kd : float, optional
The diffuser loss coefficient, [-]
Ks : float, optional
The secondary inlet loss coefficient, [-]
Kp : float, optional
The primary nozzle loss coefficient, [-]
d_nozzle : float, optional
The inside diameter of the primary fluid's nozle, [m]
d_mixing : float, optional
The diameter of the mixing chamber, [m]
d_diffuser : float, optional
The diameter of the diffuser at its exit, [m]
Qp : float, optional
The volumetric flow rate of the primary fluid, [m^3/s]
Qs : float, optional
The volumetric flow rate of the secondary fluid, [m^3/s]
P1 : float, optional
The pressure of the primary fluid entering its nozzle, [Pa]
P2 : float, optional
The pressure of the secondary fluid at the entry of the ejector, [Pa]
P5 : float, optional
The pressure at the exit of the diffuser, [Pa]
nozzle_retracted : bool, optional
Whether or not the primary nozzle's exit is before the mixing chamber,
or somewhat inside it, [-]
Returns
-------
solution : dict
Dictionary of calculated parameters, [-]
Notes
-----
The assumptions of the model are:
* The flows are one dimensional except in the mixing chamber.
* The mixing chamber has constant cross-sectional area.
* The mixing happens entirely in the mixing chamber, prior to entry into
the diffuser.
* The primary nozzle is in a straight line with the middle of the mixing
chamber.
* Both fluids are incompressible, and have no excess volume on mixing.
* Primary and secondary flows both enter the mixing throat with their
own uniform velocity distribution; the mixed stream leaves with a uniform
velocity profile.
* If the secondary fluid is a gas, it undergoes isothermal compression in
the throat and diffuser.
* If the secondary fluid is a gas or contains a bubbly gas, it is
homogeneously distributed in a continuous liquid phase.
* Heat transfer between the fluids is negligible - there is no change in
density due to temperature changes
* The change in the solubility of a disolved gas, if there is one, is
negigibly changed by temperature or pressure changes.
Examples
--------
>>> pprint(liquid_jet_pump(rhop=998., rhos=1098., Km=.186, Kd=0.12, Ks=0.11,
... Kp=0.04, d_nozzle=0.0223, d_mixing=0.045, Qs=0.01, Qp=.01, P2=133600,
... P5=200E3, nozzle_retracted=False))
{'M': 1.0,
'N': 0.2938665390183575,
'P1': 425952.91121542786,
'P2': 133600,
'P5': 200000.0,
'Qp': 0.01,
'Qs': 0.01,
'R': 0.24557530864197535,
'alpha': 1e-06,
'd_diffuser': 45.0,
'd_mixing': 0.045,
'd_nozzle': 0.0223,
'efficiency': 0.2938665390183575}
References
----------
.. [1] Karassik, Igor J., Joseph P. Messina, Paul Cooper, and Charles C.
Heald. Pump Handbook. 4th edition. New York: McGraw-Hill Education, 2007.
.. [2] Winoto S. H., Li H., and Shah D. A. "Efficiency of Jet Pumps."
Journal of Hydraulic Engineering 126, no. 2 (February 1, 2000): 150-56.
https://doi.org/10.1061/(ASCE)0733-9429(2000)126:2(150).
.. [3] Elmore, Emily, Khalid Al-Mutairi, Bilal Hussain, and A. Sherif
El-Gizawy. "Development of Analytical Model for Predicting Dual-Phase
Ejector Performance," November 11, 2016, V007T09A013.
.. [4] Ejectors and Jet Pumps. Design and Performance for Incompressible
Liquid Flow. 85032. ESDU International PLC, 1985.
'''
C = rhos/rhop
if nozzle_retracted:
j = 0.0
else:
j = 1.0
# The diffuser diameter has little effect - it can be specified, and the
# results will be a little more accurate - or it can be omitted and it
# will be set to a large value so it is ignored in the calculations.
if d_diffuser is None:
if d_mixing is not None:
d_diffuser = d_mixing*1E3
elif d_nozzle is not None:
d_diffuser = d_nozzle*1E3
unknowns = sum(i is not None for i in (d_nozzle, d_mixing, Qs, Qp, P1, P2, P5))
if unknowns < 1:
raise Exception('Too many unknowns')
elif unknowns < 1:
raise Exception('Overspecified')
if P1 is None or P2 is None or P5 is None:
# Direct solution - easy
R = d_nozzle**2/d_mixing**2
alpha = d_mixing**2/d_diffuser**2
M = Qs/Qp
M2, R2, alpha2 = M*M, R*R, alpha*alpha
num = 2.0*R + 2*C*M2*R2/(1.0 - R)
num -= R2*(1.0 + C*M)*(1.0 + M)*(1.0 + Km + Kd + alpha2)
num -= C*M2*R2/(1.0 - R)**2*(1.0 + Ks)
den = (1.0 + Kp) - 2.0*R - 2.0*C*M2*R2/(1.0 - R)
den += R2*(1.0 + C*M)*(1.0 + M)*(1.0 + Km + Kd + alpha2)
den += (1.0 - j)*(C*M2/((1.0 - R)/R)**2)*(1.0 - Ks)
N = num/den
if P1 is None:
P1 = (-P2 + P5*N + P5)/N
elif P2 is None:
P2 = -P1*N + P5*N + P5
elif P5 is None:
P5 = (P1*N + P2)/(N + 1.0)
solution = {}
solution['P1'] = P1
solution['P2'] = P2
solution['P5'] = P5
solution['d_nozzle'] = d_nozzle
solution['d_mixing'] = d_mixing
solution['d_diffuser'] = d_diffuser
solution['Qs'] = Qs
solution['Qp'] = Qp
solution['N'] = N
solution['M'] = M
solution['R'] = R
solution['alpha'] = alpha
solution['efficiency'] = M*N
return solution
[docs]def Corripio_pump_efficiency(Q):
r'''Estimates pump efficiency using the method in Corripio (1982)
as shown in [1]_ and originally in [2]_. Estimation only
.. math::
\eta_P = -0.316 + 0.24015\ln(Q) - 0.01199\ln(Q)^2
Parameters
----------
Q : float
Volumetric flow rate, [m^3/s]
Returns
-------
efficiency : float
Pump efficiency, [-]
Notes
-----
For Centrifugal pumps only.
Range is 50 to 5000 GPM, but input variable is in metric.
Values above this range and below this range will go negative,
although small deviations are acceptable.
Example 16.5 in [1]_.
Examples
--------
>>> Corripio_pump_efficiency(461./15850.323)
0.7058888670951621
References
----------
.. [1] Seider, Warren D., J. D. Seader, and Daniel R. Lewin. Product and
Process Design Principles: Synthesis, Analysis, and Evaluation.
2 edition. New York: Wiley, 2003.
.. [2] Corripio, A.B., K.S. Chrien, and L.B. Evans, "Estimate Costs of
Centrifugal Pumps and Electric Motors," Chem. Eng., 89, 115-118,
February 22 (1982).
'''
Q *= 15850.323
return -0.316 + 0.24015*log(Q) - 0.01199*log(Q)**2
[docs]def Corripio_motor_efficiency(P):
r'''Estimates motor efficiency using the method in Corripio (1982)
as shown in [1]_ and originally in [2]_. Estimation only.
.. math::
\eta_M = 0.8 + 0.0319\ln(P_B) - 0.00182\ln(P_B)^2
Parameters
----------
P : float
Power, [W]
Returns
-------
efficiency : float
Motor efficiency, [-]
Notes
-----
Example 16.5 in [1]_.
Examples
--------
>>> Corripio_motor_efficiency(137*745.7)
0.9128920875679222
References
----------
.. [1] Seider, Warren D., J. D. Seader, and Daniel R. Lewin. Product and
Process Design Principles: Synthesis, Analysis, and Evaluation.
2 edition. New York: Wiley, 2003.
.. [2] Corripio, A.B., K.S. Chrien, and L.B. Evans, "Estimate Costs of
Centrifugal Pumps and Electric Motors," Chem. Eng., 89, 115-118,
February 22 (1982).
'''
P = P/745.69987
return 0.8 + 0.0319*log(P) - 0.00182*log(P)**2
#print [Corripio_motor_efficiency(137*745.7)]
VFD_efficiencies = [[0.31, 0.77, 0.86, 0.9, 0.91, 0.93, 0.94],
[0.35, 0.8, 0.88, 0.91, 0.92, 0.94, 0.95],
[0.41, 0.83, 0.9, 0.93, 0.94, 0.95, 0.96],
[0.47, 0.86, 0.93, 0.94, 0.95, 0.96, 0.97],
[0.5, 0.88, 0.93, 0.95, 0.95, 0.96, 0.97],
[0.46, 0.86, 0.92, 0.95, 0.95, 0.96, 0.97],
[0.51, 0.87, 0.92, 0.95, 0.95, 0.96, 0.97],
[0.47, 0.86, 0.93, 0.95, 0.96, 0.97, 0.97],
[0.55, 0.89, 0.94, 0.95, 0.96, 0.97, 0.97],
[0.61, 0.91, 0.95, 0.96, 0.96, 0.97, 0.97],
[0.61, 0.91, 0.95, 0.96, 0.96, 0.97, 0.97]]
VFD_efficiency_interp = interp2d([0.016, 0.125, 0.25, 0.42, 0.5, 0.75, 1],
[3, 5, 10, 20, 30, 50, 60, 75, 100, 200, 400],
VFD_efficiencies)
[docs]def VFD_efficiency(P, load=1):
r'''Returns the efficiency of a Variable Frequency Drive according to [1]_.
These values are generic, and not standardized as minimum values.
Older VFDs often have much worse performance.
Parameters
----------
P : float
Power, [W]
load : float, optional
Fraction of motor's rated electrical capacity being used
Returns
-------
efficiency : float
VFD efficiency, [-]
Notes
-----
The use of a VFD does change the characteristics of a pump curve's
efficiency, but this has yet to be quantified. The effect is small.
This value should be multiplied by the product of the pump and motor
efficiency to determine the overall efficiency.
Efficiency table is in units of hp, so a conversion is performed internally.
If load not specified, assumed 1 - where maximum efficiency occurs.
Table extends down to 3 hp and up to 400 hp; values outside these limits
are rounded to the nearest known value. Values between standardized sizes
are interpolated linearly. Load values extend down to 0.016.
The table used is for Pulse Width Modulation (PWM) VFDs.
Examples
--------
>>> VFD_efficiency(10*hp)
0.96
>>> VFD_efficiency(100*hp, load=0.2)
0.92
References
----------
.. [1] GoHz.com. Variable Frequency Drive Efficiency.
http://www.variablefrequencydrive.org/vfd-efficiency
'''
P = P/hp
if P < 3:
P = 3
elif P > 400:
P = 400
if load < 0.016:
load = 0.016
return round(float(VFD_efficiency_interp(load, P)), 4)
nema_sizes_hp = [.25, 1/3., .5, .75, 1, 1.5, 2, 3, 4, 5, 5.5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500]
'''list: all NEMA motor sizes in increasing order, in horsepower.
'''
nema_sizes = [i*hp for i in nema_sizes_hp]
'''list: all NEMA motor sizes in increasing order, in Watts.
'''
[docs]def motor_round_size(P):
r'''Rounds up the power for a motor to the nearest NEMA standard power.
The returned power is always larger or equal to the input power.
Parameters
----------
P : float
Power, [W]
Returns
-------
P_actual : float
Actual power, equal to or larger than input [W]
Notes
-----
An exception is raised if the power required is larger than any of
the NEMA sizes. Larger motors are available, but are unstandardized.
Examples
--------
>>> motor_round_size(1E5)
111854.98073734052
References
----------
.. [1] Natural Resources Canada. Electric Motors (1 to 500 HP/0.746 to
375 kW). As modified 2015-12-17.
https://www.nrcan.gc.ca/energy/regulations-codes-standards/products/6885
'''
for P_actual in nema_sizes:
if P_actual >= P:
return P_actual
raise Exception('Required power is larger than can be provided with one valve')
nema_high_P = [1, 1.5, 2, 3, 4, 5, 5.5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 100, 125, 150, 175, 200]
nema_high_full_open_2p = [0.77, 0.84, 0.855, 0.855, 0.865, 0.865, 0.865, 0.885, 0.895, 0.902, 0.91, 0.917, 0.917, 0.924, 0.93, 0.936, 0.936, 0.936, 0.941, 0.941, 0.95, 0.95]
nema_high_full_open_4p = [0.855, 0.865, 0.865, 0.895, 0.895, 0.895, 0.895, 0.91, 0.917, 0.93, 0.93, 0.936, 0.941, 0.941, 0.945, 0.95, 0.95, 0.954, 0.954, 0.958, 0.958, 0.958]
nema_high_full_open_6p = [0.825, 0.865, 0.875, 0.885, 0.895, 0.895, 0.895, 0.902, 0.917, 0.917, 0.924, 0.93, 0.936, 0.941, 0.941, 0.945, 0.945, 0.95, 0.95, 0.954, 0.954, 0.954]
nema_high_full_closed_2p = [0.77, 0.84, 0.855, 0.865, 0.885, 0.885, 0.885, 0.895, 0.902, 0.91, 0.91, 0.917, 0.917, 0.924, 0.93, 0.936, 0.936, 0.941, 0.95, 0.95, 0.954, 0.954]
nema_high_full_closed_4p = [0.855, 0.865, 0.865, 0.895, 0.895, 0.895, 0.895, 0.917, 0.917, 0.924, 0.93, 0.936, 0.936, 0.941, 0.945, 0.95, 0.954, 0.954, 0.954, 0.958, 0.962, 0.962]
nema_high_full_closed_6p = [0.825, 0.875, 0.885, 0.895, 0.895, 0.895, 0.895, 0.91, 0.91, 0.917, 0.917, 0.93, 0.93, 0.941, 0.941, 0.945, 0.945, 0.95, 0.95, 0.958, 0.958, 0.958]
nema_high_full_open_2p_i = interp1d(nema_high_P, nema_high_full_open_2p)
nema_high_full_open_4p_i = interp1d(nema_high_P, nema_high_full_open_4p)
nema_high_full_open_6p_i = interp1d(nema_high_P, nema_high_full_open_6p)
nema_high_full_closed_2p_i = interp1d(nema_high_P, nema_high_full_closed_2p)
nema_high_full_closed_4p_i = interp1d(nema_high_P, nema_high_full_closed_4p)
nema_high_full_closed_6p_i = interp1d(nema_high_P, nema_high_full_closed_6p)
nema_min_P = [1, 1.5, 2, 3, 4, 5, 5.5, 7.5, 10, 15, 20, 25, 30, 40, 50, 60, 75, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500]
nema_min_full_open_2p = [0.755, 0.825, 0.84, 0.84, 0.84, 0.855, 0.855, 0.875, 0.885, 0.895, 0.902, 0.91, 0.91, 0.917, 0.924, 0.93, 0.93, 0.93, 0.936, 0.936, 0.945, 0.945, 0.945, 0.95, 0.95, 0.954, 0.958, 0.958]
nema_min_full_open_4p = [0.825, 0.84, 0.84, 0.865, 0.865, 0.875, 0.875, 0.885, 0.895, 0.91, 0.91, 0.917, 0.924, 0.93, 0.93, 0.936, 0.941, 0.941, 0.945, 0.95, 0.95, 0.95, 0.954, 0.954, 0.954, 0.954, 0.958, 0.958]
nema_min_full_open_6p = [0.8, 0.84, 0.855, 0.865, 0.865, 0.875, 0.875, 0.885, 0.902, 0.902, 0.91, 0.917, 0.924, 0.93, 0.93, 0.936, 0.936, 0.941, 0.941, 0.945, 0.945, 0.945, 0.954, 0.954, 0.954, 0.954, 0.954, 0.954]
nema_min_full_open_8p = [0.74, 0.755, 0.855, 0.865, 0.865, 0.875, 0.875, 0.885, 0.895, 0.895, 0.902, 0.902, 0.91, 0.91, 0.917, 0.924, 0.936, 0.936, 0.936, 0.936, 0.936, 0.936, 0.945, 0.945, 0.945, 0.945, 0.945, 0.945]
nema_min_full_closed_2p = [0.755, 0.825, 0.84, 0.855, 0.855, 0.875, 0.875, 0.885, 0.895, 0.902, 0.902, 0.91, 0.91, 0.917, 0.924, 0.93, 0.93, 0.936, 0.945, 0.945, 0.95, 0.95, 0.954, 0.954, 0.954, 0.954, 0.954, 0.954]
nema_min_full_closed_4p = [0.825, 0.84, 0.84, 0.875, 0.875, 0.875, 0.875, 0.895, 0.895, 0.91, 0.91, 0.924, 0.924, 0.93, 0.93, 0.936, 0.941, 0.945, 0.945, 0.95, 0.95, 0.95, 0.95, 0.954, 0.954, 0.954, 0.954, 0.958]
nema_min_full_closed_6p = [0.8, 0.855, 0.865, 0.875, 0.875, 0.875, 0.875, 0.895, 0.895, 0.902, 0.902, 0.917, 0.917, 0.93, 0.93, 0.936, 0.936, 0.941, 0.941, 0.95, 0.95, 0.95, 0.95, 0.95, 0.95, 0.95, 0.95, 0.95]
nema_min_full_closed_8p = [0.74, 0.77, 0.825, 0.84, 0.84, 0.855, 0.855, 0.855, 0.885, 0.885, 0.895, 0.895, 0.91, 0.91, 0.917, 0.917, 0.93, 0.93, 0.936, 0.936, 0.941, 0.941, 0.945, 0.945, 0.945, 0.945, 0.945, 0.945]
nema_min_full_open_2p_i = interp1d(nema_min_P, nema_min_full_open_2p)
nema_min_full_open_4p_i = interp1d(nema_min_P, nema_min_full_open_4p)
nema_min_full_open_6p_i = interp1d(nema_min_P, nema_min_full_open_6p)
nema_min_full_open_8p_i = interp1d(nema_min_P, nema_min_full_open_8p)
nema_min_full_closed_2p_i = interp1d(nema_min_P, nema_min_full_closed_2p)
nema_min_full_closed_4p_i = interp1d(nema_min_P, nema_min_full_closed_4p)
nema_min_full_closed_6p_i = interp1d(nema_min_P, nema_min_full_closed_6p)
nema_min_full_closed_8p_i = interp1d(nema_min_P, nema_min_full_closed_8p)
[docs]def CSA_motor_efficiency(P, closed=False, poles=2, high_efficiency=False):
r'''Returns the efficiency of a NEMA motor according to [1]_.
These values are standards, but are only for full-load operation.
Parameters
----------
P : float
Power, [W]
closed : bool, optional
Whether or not the motor is enclosed
poles : int, optional
The number of poles of the motor
high_efficiency : bool, optional
Whether or not to look up the high-efficiency value
Returns
-------
efficiency : float
Guaranteed full-load motor efficiency, [-]
Notes
-----
Criteria for being required to meet the high-efficiency standard is:
* Designed for continuous operation
* Operates by three-phase induction
* Is a squirrel-cage or cage design
* Is NEMA type A, B, or C with T or U frame; or IEC design N or H
* Is designed for single-speed operation
* Has a nominal voltage of less than 600 V AC
* Has a nominal frequency of 60 Hz or 50/60 Hz
* Has 2, 4, or 6 pole construction
* Is either open or closed
Pretty much every motor is required to meet the low-standard efficiency
table, however.
Several low-efficiency standard high power values were added to allow for
easy programming; values are the last listed efficiency in the table.
Examples
--------
>>> CSA_motor_efficiency(100*hp)
0.93
>>> CSA_motor_efficiency(100*hp, closed=True, poles=6, high_efficiency=True)
0.95
References
----------
.. [1] Natural Resources Canada. Electric Motors (1 to 500 HP/0.746 to
375 kW). As modified 2015-12-17.
https://www.nrcan.gc.ca/energy/regulations-codes-standards/products/6885
'''
P = P/hp
if high_efficiency:
if closed:
if poles == 2:
efficiency = nema_high_full_closed_2p_i(P)
elif poles == 4:
efficiency = nema_high_full_closed_4p_i(P)
elif poles == 6:
efficiency = nema_high_full_closed_6p_i(P)
else:
if poles == 2:
efficiency = nema_high_full_open_2p_i(P)
elif poles == 4:
efficiency = nema_high_full_open_4p_i(P)
elif poles == 6:
efficiency = nema_high_full_open_6p_i(P)
else:
if closed:
if poles == 2:
efficiency = nema_min_full_closed_2p_i(P)
elif poles == 4:
efficiency = nema_min_full_closed_4p_i(P)
elif poles == 6:
efficiency = nema_min_full_closed_6p_i(P)
elif poles == 8:
efficiency = nema_min_full_closed_8p_i(P)
else:
if poles == 2:
efficiency = nema_min_full_open_2p_i(P)
elif poles == 4:
efficiency = nema_min_full_open_4p_i(P)
elif poles == 6:
efficiency = nema_min_full_open_6p_i(P)
elif poles == 8:
efficiency = nema_min_full_open_8p_i(P)
return round(float(efficiency), 4)
# Test high efficiency:
#print([CSA_motor_efficiency(k*hp, high_efficiency=False, closed=i, poles=j) for i in [True, False] for j in [2, 4, 6, 8] for k in nema_min_P])
_to_1 = [0.015807118828266818, 4.3158627514876216, -8.5612097969025438, 8.2040355039147386, -3.0147603718043068]
_to_5 = [0.015560190519232379, 4.5699731811493152, -7.6800154569463883, 5.4701698738380813, -1.3630071852989643]
_to_10 = [0.059917274403963446, 6.356781885851186, -17.099192527703369, 20.707077651470666, -9.2215133149377841]
_to_25 = [0.29536141765389839, 4.9918188632064329, -13.785081664656504, 16.908273659093812, -7.5816775136809609]
_to_60 = [0.46934299949154384, 4.0298663805446004, -11.632822556859477, 14.616967043793032, -6.6284514347522245]
_to_infty = [0.68235730304242914, 2.4402956771025748, -6.8306770996860182, 8.2108432911172713, -3.5629309804411577]
_efficiency_lists = [_to_1, _to_5, _to_10, _to_25, _to_60, _to_infty]
_efficiency_ones = [0.9218102, 0.64307597, 0.61724113, 0.61569791, 0.6172238, 0.40648294]
[docs]def motor_efficiency_underloaded(P, load=0.5):
r'''Returns the efficiency of a motor operating under its design power
according to [1]_.These values are generic; manufacturers usually list 4
points on their product information, but full-scale data is hard to find
and not regulated.
Parameters
----------
P : float
Power, [W]
load : float, optional
Fraction of motor's rated electrical capacity being used
Returns
-------
efficiency : float
Motor efficiency, [-]
Notes
-----
If the efficiency returned by this function is unattractive, use a VFD.
The curves used here are polynomial fits to [1]_'s graph, and curves were
available for the following motor power ranges:
0-1 hp, 1.5-5 hp, 10 hp, 15-25 hp, 30-60 hp, 75-100 hp
If above the upper limit of one range, the next value is returned.
Examples
--------
>>> motor_efficiency_underloaded(1*hp)
0.8705179600980149
>>> motor_efficiency_underloaded(10.1*hp, .1)
0.6728425932357025
References
----------
.. [1] Washington State Energy Office. Energy-Efficient Electric Motor
Selection Handbook. 1993.
'''
P = P/hp
if P <=1:
i = 0
elif P <= 5:
i = 1
elif P <= 10:
i = 2
elif P <= 25:
i = 3
elif P <= 60:
i = 4
else:
i = 5
if load > _efficiency_ones[i]:
return 1
else:
cs = _efficiency_lists[i]
return cs[0] + cs[1]*load + cs[2]*load**2 + cs[3]*load**3 + cs[4]*load**4
[docs]def specific_speed(Q, H, n=3600.):
r'''Returns the specific speed of a pump operating at a specified Q, H,
and n.
.. math::
n_S = \frac{n\sqrt{Q}}{H^{0.75}}
Parameters
----------
Q : float
Flow rate, [m^3/s]
H : float
Head generated by the pump, [m]
n : float, optional
Speed of pump [rpm]
Returns
-------
nS : float
Specific Speed, [rpm*m^0.75/s^0.5]
Notes
-----
Defined at the BEP, with maximum fitting diameter impeller, at a given
rotational speed.
Examples
--------
Example from [1]_.
>>> specific_speed(0.0402, 100, 3550)
22.50823182748925
References
----------
.. [1] HI 1.3 Rotodynamic Centrifugal Pumps for Design and Applications
'''
return n*Q**0.5/H**0.75
[docs]def specific_diameter(Q, H, D):
r'''Returns the specific diameter of a pump operating at a specified Q, H,
and D.
.. math::
D_s = \frac{DH^{1/4}}{\sqrt{Q}}
Parameters
----------
Q : float
Flow rate, [m^3/s]
H : float
Head generated by the pump, [m]
D : float
Pump impeller diameter [m]
Returns
-------
Ds : float
Specific diameter, [m^0.25/s^0.5]
Notes
-----
Used in certain pump sizing calculations.
Examples
--------
>>> specific_diameter(Q=0.1, H=10., D=0.1)
0.5623413251903491
References
----------
.. [1] Green, Don, and Robert Perry. Perry's Chemical Engineers' Handbook,
Eighth Edition. McGraw-Hill Professional, 2007.
'''
return D*H**0.25/Q**0.5
[docs]def speed_synchronous(f, poles=2, phase=3):
r'''Returns the synchronous speed of a synchronous motor according to [1]_.
.. math::
N_s = \frac{120 f \cdot\text{phase}}{\text{poles}}
Parameters
----------
f : float
Line frequency, [Hz]
poles : int, optional
The number of poles of the motor
phase : int, optional
Line AC phase
Returns
-------
Ns : float
Speed of synchronous motor, [rpm]
Notes
-----
Synchronous motors have no slip. Large synchronous motors are not
self-starting.
Examples
--------
>>> speed_synchronous(50, poles=12)
1500.0
>>> speed_synchronous(60, phase=1)
3600.0
References
----------
.. [1] All About Circuits. Synchronous Motors. Chapter 13 - AC Motors
http://www.allaboutcircuits.com/textbook/alternating-current/chpt-13/synchronous-motors/
'''
return 120.*f*phase/poles
[docs]def current_ideal(P, V, phase=3, PF=1):
r'''Returns the current drawn by a motor of power `P` operating at voltage
`V`, with line AC of phase `phase` and power factor `PF` according to [1]_.
Single-phase power:
.. math::
I = \frac{P}{V \cdot \text{PF}}
3-phase power:
.. math::
I = \frac{P}{V \cdot \text{PF} \sqrt{3}}
Parameters
----------
P : float
Power, [W]
V : float
Voltage, [V]
phase : int, optional
Line AC phase, either 1 or 3
PF : float, optional
Power factor of motor
Returns
-------
I : float
Power drawn by motor, [A]
Notes
-----
Does not include power used by the motor's fan, or startor, or internal
losses. These are all significant.
Examples
--------
>>> current_ideal(V=120, P=1E4, PF=1, phase=1)
83.33333333333333
References
----------
.. [1] Electrical Construction, and Maintenance. "Calculating Single- and
3-Phase Parameters." April 1, 2008.
http://ecmweb.com/basics/calculating-single-and-3-phase-parameters.
'''
if phase not in [1, 3]:
raise Exception('Only 1 and 3 phase power supported')
if phase == 3:
return P/(V*3**0.5*PF)
else:
return P/(V*PF)
with open(os.path.join(folder, 'residential power.csv'), encoding='utf-8') as f:
residential_power_raw = f.read()
with open(os.path.join(folder, '3 phase power.csv'), encoding='utf-8') as f:
industrial_power_raw = f.read()
residential_power = {}
industrial_power = {}
residential_power_data = namedtuple('residential_power_data', ['plugs', 'voltage', 'freq', 'country'])
industrial_power_data = namedtuple('industrial_power_data', ['voltage', 'freq', 'country'])
for line in residential_power_raw.split('\n')[1:]:
country, code, plugs, voltage, freq = line.split('\t')
plugs = plugs.replace(' ', '').split(',')
residential_power[code] = residential_power_data(plugs, int(voltage), int(freq), country)
for line in industrial_power_raw.split('\n')[1:]:
code, country, voltage, freq = line.split('\t')
voltage = [int(i) for i in voltage.replace(' ', '').split(',')]
industrial_power[code] = industrial_power_data(voltage, int(freq), country)
plug_types = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N']
voltages_1_phase_residential = [100, 110, 115, 120, 127, 220, 230, 240]
voltages_3_phase = [120, 190, 200, 208, 220, 230, 240, 277, 380, 400, 415, 440, 480]
frequencies = [50, 60]
# https://www.grainger.com/content/supplylink-v-belt-maintenance-key-to-electric-motor-efficiency
# Source of values for v belt, notched, and synchronous
# Technology assessment: energy-efficient belt transmissions
# Source of cogged value, their range is 95-98
V_BELT = 'V'
COGGED_V_BELT = 'cogged'
NOTCHED_BELT = 'notched'
SYNCHRONOUS_BELT = 'synchronous'
belt_efficiencies = {V_BELT: 0.95,
NOTCHED_BELT: 0.97,
COGGED_V_BELT: 0.965,
SYNCHRONOUS_BELT: 0.98}
DEEP_GROOVE_BALL = "Deep groove ball"
ANGULAR_CONTACT_BALL_SINGLE_ROW = "Angular contact ball Single row"
ANGULAR_CONTACT_BALL_DOUBLE_ROW = "Angular contact ball Double row"
FOUR_POINT_CONTACT_BALL = "Four point contact ball"
SELF_ALIGNING_BALL = "Self aligning ball"
CYLINDRICAL_ROLLER_WITH_CAGE = "Cylindrical roller with cage"
CYLINDRICAL_ROLLER_FULL_COMPLEMENT = "Cylindrical roller full complement"
NEEDLE_ROLLER = "Needle roller"
TAPER_ROLLER = "Taper roller"
SPHERICAL_ROLLER = "Spherical roller"
THRUST_BALL = "Thrust ball"
CYLINDRICAL_ROLLER_THRUST = "Cylindrical roller thrust"
NEEDLE_ROLLER_THRUST = "Needle roller thrust"
SPHERICAL_ROLLER_THRUST = "Spherical roller thrust"
bearing_friction_factors = {DEEP_GROOVE_BALL: 0.0015,
ANGULAR_CONTACT_BALL_SINGLE_ROW: 0.002,
ANGULAR_CONTACT_BALL_DOUBLE_ROW: 0.0024,
FOUR_POINT_CONTACT_BALL: 0.0024,
SELF_ALIGNING_BALL: 0.001,
CYLINDRICAL_ROLLER_WITH_CAGE: 0.0011,
CYLINDRICAL_ROLLER_FULL_COMPLEMENT: 0.002,
NEEDLE_ROLLER: 0.0025,
TAPER_ROLLER: 0.0018,
SPHERICAL_ROLLER: 0.0018,
THRUST_BALL: 0.0013,
CYLINDRICAL_ROLLER_THRUST: 0.005,
NEEDLE_ROLLER_THRUST: 0.005,
SPHERICAL_ROLLER_THRUST: 0.0018}
# In mm, diameter of fans -> convert to SI
fan_diameters = [125, 132, 140, 150, 160, 170, 180, 190, 200, 212, 224, 236, 250, 265, 280, 300, 315, 335, 355, 375, 400, 425, 450, 475, 500, 530, 560, 600, 630, 670, 710, 750, 800, 850, 900, 950, 1000]
fan_diameters = [i*1E-3 for i in fan_diameters]
FEG90 = [42.5, 44.8, 47.2, 50.1, 52.7, 55.2, 57.4, 59.4, 61.3, 63.3, 65.2, 66.9, 68.6, 70.3, 71.8, 73.5, 74.6, 75.9, 77, 77.9, 78.9, 79.7, 80.4, 81, 81.5, 81.9, 82.3, 82.7, 83, 83.3, 83.5, 83.7, 83.8, 84, 84.1, 84.1, 84.1]
FEG85 = [40.1, 42.3, 44.6, 47.3, 49.8, 52.1, 54.2, 56.1, 57.9, 59.8, 61.6, 63.1, 64.8, 66.4, 67.8, 69.4, 70.4, 71.7, 72.7, 73.6, 74.5, 75.3, 75.9, 76.5, 76.9, 77.4, 77.7, 78.1, 78.4, 78.6, 78.8, 79, 79.1, 79.3, 79.3, 79.4, 79.4]
FEG80 = [37.8, 39.9, 42.1, 44.7, 47, 49.2, 51.1, 53, 54.6, 56.5, 58.1, 59.6, 61.2, 62.7, 64, 65.5, 66.5, 67.6, 68.6, 69.5, 70.3, 71.1, 71.7, 72.2, 72.6, 73, 73.4, 73.8, 74, 74.2, 74.4, 74.6, 74.7, 74.8, 74.9, 75, 75]
FEG75 = [35.7, 37.7, 39.8, 42.2, 44.4, 46.4, 48.3, 50, 51.6, 53.3, 54.9, 56.3, 57.8, 59.2, 60.4, 61.8, 62.8, 63.9, 64.8, 65.6, 66.4, 67.1, 67.7, 68.1, 68.5, 68.9, 69.3, 69.6, 69.8, 70.1, 70.3, 70.4, 70.5, 70.6, 70.7, 70.8, 70.8]
FEG71 = [33.7, 35.6, 37.5, 39.8, 41.9, 43.8, 45.6, 47.2, 48.7, 50.3, 51.8, 53.1, 54.5, 55.9, 57, 58.4, 59.3, 60.3, 61.2, 61.9, 62.7, 63.3, 63.9, 64.3, 64.7, 65.1, 65.4, 65.7, 65.9, 66.1, 66.3, 66.5, 66.6, 66.7, 66.8, 66.8, 66.8]
FEG67 = [31.8, 33.6, 35.4, 37.6, 39.5, 41.4, 43, 44.6, 46, 47.5, 48.9, 50.2, 51.5, 52.7, 53.8, 55.1, 55.9, 56.9, 57.7, 58.4, 59.2, 59.8, 60.3, 60.7, 61.1, 61.4, 61.7, 62.1, 62.2, 62.4, 62.6, 62.7, 62.9, 63, 63, 63.1, 63.1]
FEG63 = [30.1, 31.7, 33.4, 35.5, 37.3, 39, 40.6, 42.1, 43.4, 44.8, 46.2, 47.3, 48.6, 49.8, 50.8, 52, 52.8, 53.7, 54.5, 55.2, 55.9, 56.5, 56.9, 57.3, 57.7, 58, 58.3, 58.6, 58.8, 59, 59.1, 59.2, 59.4, 59.4, 59.5, 59.5, 59.6]
FEG60 = [28.4, 29.9, 31.6, 33.5, 35.2, 36.9, 38.3, 39.7, 41, 42.3, 43.6, 44.7, 45.9, 47, 48, 49.1, 49.9, 50.7, 51.5, 52.1, 52.8, 53.3, 53.8, 54.1, 54.5, 54.8, 55, 55.3, 55.5, 55.7, 55.8, 55.9, 56, 56.1, 56.2, 56.2, 56.2]
FEG56 = [26.8, 28.2, 29.8, 31.6, 33.3, 34.8, 36.2, 37.5, 38.7, 40, 41.1, 42.2, 43.3, 44.4, 45.3, 46.4, 47.1, 47.9, 48.6, 49.2, 49.8, 50.3, 50.7, 51.1, 51.4, 51.7, 51.9, 52.2, 52.4, 52.5, 52.7, 52.8, 52.9, 53, 53, 53.1, 53.1]
FEG53 = [25.3, 26.7, 28.1, 29.8, 31.4, 32.9, 34.2, 35.4, 36.5, 37.7, 38.8, 39.8, 40.9, 41.9, 42.8, 43.8, 44.4, 45.2, 45.9, 46.4, 47, 47.5, 47.9, 48.2, 48.5, 48.8, 49, 49.3, 49.4, 49.6, 49.7, 49.8, 49.9, 50, 50.1, 50.1, 50.1]
FEG50 = [23.9, 25.2, 26.6, 28.2, 29.7, 31, 32.3, 33.4, 34.5, 35.6, 36.7, 37.6, 38.6, 39.5, 40.4, 41.3, 42, 42.7, 43.3, 43.8, 44.4, 44.8, 45.2, 45.5, 45.8, 46.1, 46.3, 46.5, 46.7, 46.8, 47, 47, 47.1, 47.2, 47.3, 47.3, 47.3]
fan_bare_shaft_efficiencies = {'FEG90': FEG90,
'FEG85': FEG85,
'FEG80': FEG80,
'FEG75': FEG75,
'FEG71': FEG71,
'FEG67': FEG67,
'FEG63': FEG63,
'FEG60': FEG60,
'FEG56': FEG56,
'FEG53': FEG53,
'FEG50': FEG50}
# TODO convert efficiencies to fractions
'''for key, values in fan_bare_shaft_efficiencies.items():
plt.plot(fan_diameters, values, label=key)
plt.legend()
plt.show()'''
FMEG_axial_powers = [125.0, 300.0, 1000.0, 2500.0, 5000.0, 8000.0, 10000.0, 20000.0, 60000.0, 160000.0, 300000.0, 375000.0, 500000.0]
FMEG27 = [15, 17.4, 20.7, 23.2, 25.1, 26.4, 27, 27.5, 28.3, 29.1, 29.6, 29.7, 30]
FMEG31 = [19, 21.4, 24.7, 27.2, 29.1, 30.4, 31, 31.5, 32.3, 33.1, 33.6, 33.7, 34]
FMEG35 = [23, 25.4, 28.7, 31.2, 33.1, 34.4, 35, 35.5, 36.3, 37.1, 37.6, 37.7, 38]
FMEG39 = [27, 29.4, 32.7, 35.2, 37.1, 38.4, 39, 39.5, 40.3, 41.1, 41.6, 41.7, 42]
FMEG42 = [30, 32.4, 35.7, 38.2, 40.1, 41.4, 42, 42.5, 43.3, 44.1, 44.6, 44.7, 45]
FMEG46 = [34, 36.4, 39.7, 42.2, 44.1, 45.4, 46, 46.5, 47.3, 48.1, 48.6, 48.7, 49]
FMEG50 = [38, 40.4, 43.7, 46.2, 48.1, 49.4, 50, 50.5, 51.3, 52.1, 52.6, 52.7, 53]
FMEG53 = [41, 43.4, 46.7, 49.2, 51.1, 52.4, 53, 53.5, 54.3, 55.1, 55.6, 55.7, 56]
FMEG55 = [43, 45.4, 48.7, 51.2, 53.1, 54.4, 55, 55.5, 56.3, 57.1, 57.6, 57.7, 58]
FMEG58 = [46, 48.4, 51.7, 54.2, 56.1, 57.4, 58, 58.5, 59.3, 60.1, 60.6, 60.7, 61]
FMEG60 = [48, 50.4, 53.7, 56.2, 58.1, 59.4, 60, 60.5, 61.3, 62.1, 62.6, 62.7, 63]
FMEG62 = [50, 52.4, 55.7, 58.2, 60.1, 61.4, 62, 62.5, 63.3, 64.1, 64.6, 64.7, 65]
FMEG64 = [52, 54.4, 57.7, 60.2, 62.1, 63.4, 64, 64.5, 65.3, 66.1, 66.6, 66.7, 67]
FMEG66 = [54, 56.4, 59.7, 62.2, 64.1, 65.4, 66, 66.5, 67.3, 68.1, 68.6, 68.7, 69]
fan_driven_axial_efficiencies = {'FMEG27': FMEG27,
'FMEG31': FMEG31,
'FMEG35': FMEG35,
'FMEG39': FMEG39,
'FMEG42': FMEG42,
'FMEG46': FMEG46,
'FMEG50': FMEG50,
'FMEG53': FMEG53,
'FMEG55': FMEG55,
'FMEG58': FMEG58,
'FMEG60': FMEG60,
'FMEG62': FMEG62,
'FMEG64': FMEG64,
'FMEG66': FMEG66}
FMEG_centrifugal_backward_powers = FMEG_axial_powers
FMEG35 = [15, 19, 24.5, 28.7, 31.8, 34, 35, 35.7, 36.9, 38, 38.7, 38.9, 39.2]
FMEG39 = [19, 23, 28.5, 32.7, 35.8, 38, 39, 39.7, 40.9, 42, 42.7, 42.9, 43.2]
FMEG42 = [22, 26, 31.5, 35.7, 38.8, 41, 42, 42.7, 43.9, 45, 45.7, 45.9, 46.2]
FMEG46 = [26, 30, 35.5, 39.7, 42.8, 45, 46, 46.7, 47.9, 49, 49.7, 49.9, 50.2]
FMEG50 = [30, 34, 39.5, 43.7, 46.8, 49, 50, 50.7, 51.9, 53, 53.7, 53.9, 54.2]
FMEG53 = [33, 37, 42.5, 46.7, 49.8, 52, 53, 53.7, 54.9, 56, 56.7, 56.9, 57.2]
FMEG55 = [35, 39, 44.5, 48.7, 51.8, 54, 55, 55.7, 56.9, 58, 58.7, 58.9, 59.2]
FMEG58 = [38, 42, 47.5, 51.7, 54.8, 57, 58, 58.7, 59.9, 61, 61.7, 61.9, 62.2]
FMEG60 = [40, 44, 49.5, 53.7, 56.8, 59, 60, 60.7, 61.9, 63, 63.7, 63.9, 64.2]
FMEG62 = [42, 46, 51.5, 55.7, 58.8, 61, 62, 62.7, 63.9, 65, 65.7, 65.9, 66.2]
FMEG64 = [44, 48, 53.5, 57.7, 60.8, 63, 64, 64.7, 65.9, 67, 67.7, 67.9, 68.2]
FMEG66 = [46, 50, 55.5, 59.7, 62.8, 65, 66, 66.7, 67.9, 69, 69.7, 69.9, 70.2]
FMEG68 = [48, 52, 57.5, 61.7, 64.8, 67, 68, 68.7, 69.9, 71, 71.7, 71.9, 72.2]
FMEG70 = [50, 54, 59.5, 63.7, 66.8, 69, 70, 70.7, 71.9, 73, 73.7, 73.9, 74.2]
FMEG72 = [52, 56, 61.5, 65.7, 68.8, 71, 72, 72.7, 73.9, 75, 75.7, 75.9, 76.2]
FMEG74 = [54, 58, 63.5, 67.7, 70.8, 73, 74, 74.7, 75.9, 77, 77.7, 77.9, 78.2]
FMEG76 = [56, 60, 65.5, 69.7, 72.8, 75, 76, 76.7, 77.9, 79, 79.7, 79.9, 80.2]
fan_centrifugal_backward_efficiencies = {'FMEG35': FMEG35,
'FMEG39': FMEG39,
'FMEG42': FMEG42,
'FMEG46': FMEG46,
'FMEG50': FMEG50,
'FMEG53': FMEG53,
'FMEG55': FMEG55,
'FMEG55': FMEG55,
'FMEG58': FMEG58,
'FMEG60': FMEG60,
'FMEG62': FMEG62,
'FMEG64': FMEG64,
'FMEG66': FMEG66,
'FMEG68': FMEG68,
'FMEG70': FMEG70,
'FMEG72': FMEG72,
'FMEG74': FMEG74,
'FMEG76': FMEG76}
FMEG_cross_flow_powers = [130.0, 300.0, 500.0, 800.0, 1000.0, 2000.0, 3000.0, 4000.0, 5000.0, 8000.0, 10000.0, 16000.0, 22000.0]
FMEG08 = [3, 4, 4.6, 5.1, 5.4, 6.2, 6.7, 7, 7.2, 7.8, 8, 8, 8]
FMEG11 = [6, 7, 7.6, 8.1, 8.4, 9.2, 9.7, 10, 10.2, 10.8, 11, 11, 11]
FMEG14 = [9, 10, 10.6, 11.1, 11.4, 12.2, 12.7, 13, 13.2, 13.8, 14, 14, 14]
FMEG19 = [14, 15, 15.6, 16.1, 16.4, 17.2, 17.7, 18, 18.2, 18.8, 19, 19, 19]
FMEG23 = [18, 19, 19.6, 20.1, 20.4, 21.2, 21.7, 22, 22.2, 22.8, 23, 23, 23]
FMEG28 = [23, 24, 24.6, 25.1, 25.4, 26.2, 26.7, 27, 27.2, 27.8, 28, 28, 28]
FMEG32 = [27, 28, 28.6, 29.1, 29.4, 30.2, 30.7, 31, 31.2, 31.8, 32, 32, 32]
fan_crossflow_efficiencies = {'FMEG08': FMEG08,
'FMEG11': FMEG11,
'FMEG14': FMEG14,
'FMEG19': FMEG19,
'FMEG23': FMEG23,
'FMEG28': FMEG28,
'FMEG32': FMEG32}
'''Convert the efficiencies of:
* Bare shafts
* Centrifugal backward bladed mixed flow fans
* Cross flow driven fans
* Driven forward curved radial centrifugal fans
to fractions, instead of percents.
'''
for d in (fan_bare_shaft_efficiencies, fan_driven_axial_efficiencies, fan_centrifugal_backward_efficiencies, fan_crossflow_efficiencies):
for values in d.values():
for i in range(len(values)):
values[i] = values[i]*1E-2