Note: Descriptions are shown in the official language in which they were submitted.
BEST-FIT AFFINITY SENSORLESS CONVERSION MEANS OR TECHNIQUE
FOR PUMP DIFFERENTIAL PRESSURE AND FLOW MONITORING
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a technique for controlling the operation of
a
pump; and more particularly, the present invention relates to a method and
apparatus for controlling and/or monitoring a pump, e.g., including for
domestic and
commercial heating or cooling water systems.
2. Brief Description of Related Art
Introduction
Hydronic pumping system sensorless control and monitoring techniques are
known in the art, e.g., including a 3D discrete and a mixed theoretical and 3D
discrete sensorless conversion methods, consistent with that disclosed in the
aforementioned related patent application identified as reference nos. 3-5.
The
system pressure and flow rate may be resolved directly from a pair of motor
readout
values with a conversion error around 5-15% by the 3D discrete sensorless
converter, e.g., based upon pump calibration data in the aforementioned
reference
no. 4. The mixed theoretical and discrete sensorless converter disclosed in
the
aforementioned reference no. 3, on the other hand, yields a conversion error
around
10-20% without a need of instrumentation calibration, even though a power
distribution data with respect to system coefficient and motor speed is still
needed to
.. convert the system coefficient on a varying hydronic system.
Pump sensorless data calibration, including the instrumentation and data
acquisition process, is an interesting discussion topic on pump sensorless
CA 2944881 2944881 2018-10-01
applications, which may not be easy achievable at all due to the lack of
pressure and
flow sensors for most pumping applications scenarios. In fact, it may be quite
time
consuming and tedious as well to collect the calibration data for a sensorless
pump
and motor combination product even to do it in manufacturing assembly lines,
not to
mention using expensive data acquisition instrumentations as well as hydronic
pumping testing systems setups. Therefore, the inventors of this application
recognize and appreciate that a sensorless means or technique with no need or
less
need on the calibration data may be more favorable for most sensorless pump
control applications.
For a dynamic hydronic system with its flow rate regulated by valves or
regulators, the equivalent hydronic system characteristics coefficient is an
unknown
variable in general dependent on the valves open position and system dynamic
friction loss as well. The pump efficiency under such a varying hydronic
system is a
changing variable due to motor speed slip under the varying hydronic load as
well as
some pump mechanical friction induced thermal consumption effects, especially
at
low speed with system nearly shut off. Therefore, the inventors of this
application
also recognize and appreciate that it is a quite challenge job to formulate
any
theoretic expressions for the reconstruction of a pump sensorless converter
which
yields the system pressure and flow directly from motor readout values, such
as
power, current, torque, speed, and so on so forth.
SUMMARY OF THE INVENTION
In summary, the present invention provides a new and unique best-fit affinity
sensorless conversion means or technique for deriving pump or system pressure
and flow rate at a given pair of motor readout values of power and speed,
e.g.,
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based upon using pump and system characteristics equations together with an
empirical power equation. The pump characteristics equation and the empirical
power equation may be reconstructed by a polynomial best-fit function together
with
the pump affinity laws or its modified version, e.g., based upon the pump
curve
published by pump manufacturers. System pressures and flow rate may be,
therefore, resolved at the stead state equilibrium point of pump and system
pressures by the pump and system characteristics equations as well as the
empirical
power equation accordingly. The sensorless model and technique disclosed
herein
is much easier to be applied for most practical hydronic pumping sensorless
control
.. and monitoring applications with quite satisfactory accuracy without a need
of the
instrumentation calibration.
The instant application provides a technique that is a further development of,
and builds on, the aforementioned family of technologies set forth above.
Particular Embodiments
According to some embodiments, the present invention may include, or take
the form of, apparatus featuring a signal processor or processing module
configured
at least to:
receive signaling containing information about motor readout values of
power and speed, and also about pump and system characteristics equations
together with empirical power equations that are constructed by a polynomial
best-fit function together with pump affinity laws based upon a pump curve
published by a pump manufacturer; and
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determine corresponding signaling containing information about a
pump or system pressure and a flow rate at the motor readout values of
power and speed, based upon the signaling received.
In operation, the signal processor or processing module may be configured to
resolve pump differential pressures and flow rate at an equilibrium point of
the pump
or system pressure at a motor steady state condition.
In operation, the signal processor or processing module 10a may also be
configured to provide corresponding signaling containing information about the
pump
or system pressure and the flow rate, including for pump differential pressure
and
flow monitoring. The corresponding signaling may be used to control a hydronic
pumping system.
Embodiments are also envisioned in which the apparatus includes, or takes
the form of, the hydronic pumping system, e.g., having such a signal processor
or
processing module.
The signaling received may be sensed and received from suitable sensors
configured to measure motor readout values of power and speed.
The signaling received may be stored and received from suitable memory
modules, e.g., configured with pump and system characteristics equations
together
with empirical power equations that are constructed by a polynomial best-fit
function
together with pump affinity laws based upon a pump curve published by a pump
manufacturer.
By way of example, the signal processor or processing module may include,
or take the form of, at least one processor and at least one memory including
computer program code, and the at least one memory and computer program code
are configured to, with at least one processor, to cause the signal processor
or
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processing module at least to receive the signaling (or, for example,
associated
signaling) and determine the adaptive pressure set point. The signal processor
or
processing module may be configured to suitable computer program code in order
to
implement suitable signal processing algorithms and/or functionality,
consistent with
that set forth herein.
The apparatus may include, or take the form of, a pump control or controller,
including a PI D control, having the signal processor or signal processor
module, e.g.,
including for monitoring pump differential pressure and flow.
According to some embodiments, the present invention may take the form of
a method including steps for: receiving in a signal processor or processing
module
signaling containing information about motor readout values of power and
speed,
and also about pump and system characteristics equations together with
empirical
power equations that are constructed by a polynomial best-fit function
together with
pump affinity laws based upon a pump curve published by a pump manufacturer;
and determining in the signal processor or processing module corresponding
signaling containing information about a pump or system pressure and a flow
rate at
the motor readout values of power and speed, based upon the signaling
received.
The method may also include one or more of the features set forth herein,
including providing from the signal processor or processing module
corresponding
signaling containing information about the pump or system pressure and the
flow
rate, e.g., which may be used to control a hydronic pumping system.
The present invention may also, e. g., take the form of a computer program
product having a computer readable medium with a computer executable code
embedded therein for implementing the method, e.g., when run on a signaling
processing device that forms part of such a pump controller. By way of
example, the
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CA 2944881 2018-10-01
computer program product may, e. g., take the form of a CD, a floppy disk, a
memory stick, a memory card, as well as other types or kind of memory devices
that
may store such a computer executable code on such a computer readable medium
either now known or later developed in the future.
In conclusion, the embodiments disclosed herein provides best-fit affinity
sensorless conversion means or techniques for deriving pump or system pressure
and flow rate at a given pair of motor readout values of power and speed,
e.g.,
based upon using pump and system characteristics equations together with
empirical power equations. The pump characteristics equation and the empirical
power equation may be constructed by the polynomial best-fit function together
with
the pump affinity laws based upon the pump curve published by pump
manufacturers, e.g., that may be stored in suitable memory module and
processed
accordingly. Pump differential pressures and flow rate may be resolved at the
equilibrium point of pump and system pressures at the motor steady state
.. accordingly. The pump sensorless conversion means or technique disclosed
herein
may be much easier to be applied for most practical hydronic pumping control
and
monitoring applications with satisfactory accuracy.
BRIEF DESCRIPTION OF THE DRAWING
The drawing includes the following Figures, which are not necessarily drawn
to scale:
Figure 1 is a schematic diagram of a hydronic sensorless pumping control
system that is known in the art, e.g., in which the present invention may be
implemented, according to some embodiment.
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Figure 2 is a schematic diagram of sensorless conversion for pump pressure
and flow rate from sensed power and speed.
Figure 3 is a graph of pressure (Ft) in relation to flow (GPM) showing pump,
system and power characteristics curves and a pressure equilibrium point at a
steady state, according to implementation of some embodiments of the present
invention.
Figure 4 is a graph of power (hp) in relation to system characteristics
(Cy/CyDutY) flow (GPM) showing motor power and system characteristics,
according to
implementation of some embodiments of the present invention.
Figure 5 is a graph of pressure (Ft) with respect to flow (GPM) showing pump
differential pressure versus system flow rate from the sensorless converter
(see solid
lines) and the measured or sensed data from sensors (see symbols (e.g.,
diamonds,
triangles, stars, plus signs, minus signs, boxes, and "x"s) at various speeds,
including 24Hz, 30Hz, 36Hz, 42Hz, 48Hz, 54Hz and 60Hz.
Figure 6 is a block diagram of apparatus, e.g., having a signal processor or
processing module configured for implementing the signal processing
functionality,
according to some embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 shows a hydronic sensorless pumping control system having a
combination of a centrifugal pump connected to piping with a flow and a
controller,
e.g., in which the present invention may be implemented. The sensorless
conversion for pump differential pressure and flow rate associated with the
equivalent hydronic system characteristics coefficient variable at the
discharge of a
pump and the motor power and speed at the other end of a motor drive is shown
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schematically in Figure 2. Pump, system and power characteristics curves as
well
as the corresponding pressure equilibrium point of pump and system pressures
at a
steady state for a close loop system with a static suction pressure are
presented
schematically in Figure. 3.
Considering a close loop system with a static suction pressure, the system
flow rate and pressure at a motor speed and a system position may be resolved
at
the steady state equilibrium point of pump and system pressures which is the
intersection of the pump and system curves functions shown schematically in
Figure.
3. Here, the instant pump characteristic curve, which is the pump differential
pressure P with respect to flow rate Q and motor speed of n, may be
represented
approximately in a polynomial form of P = f (Q , n) based upon the pump curve
at
motor full speed nmaõas well as the pump affinity law. The system flow rate
may,
therefore, be resolved by the pump differential pressure function of P = f
(Q,n)
together with the system flow equation of C, = Q/Nr-P subsequently. The pump
affinity laws cited here denotes the equations for pump flow, differential
pressure and
motor power, i.e., 0/0
-.max = n nmax, P Prncx = (71171max)2a1d W I Wmax nmax)3
respectively.
Following the approach described above by, e.g., using a second order best-
fit affinity pump curve function together with system flow equation
specifically, for
instance, the system flow rate may be derived using Equation (1) as:
Q(n, Cy) ___________ n ( b Vb2 - 4c (a - C,T2))/ (a - C;2), (1)
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where C,, is the system coefficient, and a, b and c are the coefficients of a
second
order best-fit pump curve function at motor full speed of nmd, . The pump
differential
pressure function of P = f (Q ,n) used here may be in form of Equation (2) as:
P(n, Q) = (aQ2 b(n In max)1(2 + (ninmax)20. (2)
Noted that other expressions of system flow rate and pump differential
equations
may be derived as well if other kinds of curve fitting or interpolating
approaches may
be chosen, for instance, a third order polynomial form of fitting or
interpolating may
be instead of that set forth herein.
To resolve the system flow rate and pressure at a steady pressure equilibrium
point from a given pair of motor power and speed by Eqs. 1 and 2, the
corresponding
dynamic system characteristic coefficient should typically be known first. For
a
varying hydronic system with flow regulated by valves or other flow
regulators,
however, there is no simple close form solution on that. As disclosed herein,
an
empirical power and system characteristics relation based on the power curve
at
motor full speed nmaxas well as the affinity law may be used, which is
schematically
shown in Figure 4. Here, the motor power function at maximum speed with
respect
to the system coefficient may be reconstructed first by using a fitting or
interpolating
technique. The motor power at a given motor speed of, e.g., W = W(C,,71), may
then
be formulated by utilizing pump affinity laws accordingly.
By using a second order best-fit affinity power function following the
approach
described above specifically, for instance, the system coefficient C, may be
expressed explicitly in form of Equation (3) as:
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B wrinnar)3-(C-4B2)
Gtorm ti) _____________________________________ A A (3)
2A
where w is motor power at a speed of n, A, B and C are the coefficients of the
second order best-fit motor power function at motor maximum speed with respect
to
the normalized system coefficient of Cl,wrra. The motor power function at any
instant
speed, w = w(Cõ,n), may be expressed in form of Equation (4) as:
\ 3 , 2
w(Cõ, n) ILmax,) n (A (C' + + (C ¨ ¨B2)) . (4)
2A 4A
In case if there may be any accuracy requirement at low speed region and
with system nearly shut down, the pump power affinity law may not be
sufficient to
represent the relation of motor power and speed well due to motor speed slip
in that
region. Slightly larger power value at low speed region results in a little
larger the
system coefficient value from the power inversion by Eq. 3, so a little larger
flow rate
from Eq. 1 as well consequently. A modified affinity law for motor power and
speed
representation may, therefore, be needed and Eq. 4 may be rewritten in the
form of
Equation (5) as:
2
w(C,õ n) = f * (7-)(A + ¨B (C ¨ ¨B2)) , (5)
2A 4A
where f*() is the modified affinity law in form of the third order polynomial
approximation in the form of Equation (6) as:
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CA 2944881 2018-10-01
f * (1) = (A' (n nmc,)3 + B (n. / n,,,x)2 + C (n/Timax)1 + D'), (6)
where A', B C' and D' are the coefficients of the third order best-fit power
function of
the power values normalized at maximum speed with respect to the normalized
motor speed of n/nmax. Instead of the pump power affinity law of
w/wma, = (n/nn,õ)3, the modified affinity law is the third order polynomial
approximation for representing power and speed relation, which is obtained
through
fitting or interpolating with an array of power values measured at a set of
given
speeds at a system position. The system position can be anywhere from shut off
to
fully open, since the normalized power distribution of f(n) is nearly
identical at any
system position. Similarly, and by way of further example, Equations nos. 3- 6
may
be presented in some other expressions as well if other kinds of curve fitting
or
interpolating approaches are used alternatively.
The system flow rate and pressure at the equilibrium point of pump and
system pressure at a steady state motor speed associated with its
corresponding
power consumption can, therefore, be obtained by Equations 1 and 2, as far as
the
system coefficient of C is obtained by use of Equations 3 and 4 or 5
accordingly,
which may be called the so-called best-fit affinity sensorless converter in
this
disclosure. By using the best-fit affinity sensorless converter, the pressure
and flow
rate values may be collected from a pumping system and compared with the data
measured from sensors. The results shown in Figure 5 demonstrates quite
satisfactory accuracy mostly around 5-10% error at whole speed regions from 30
up
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to 60 Hz in pump normal working hydronic region and around 10-20% error at low
speed region and when system is nearly shut off in general.
The best-fit affinity sensorless converter disclosed herein may be used for
most practical hydronic pumping control and monitoring applications, since it
is
formulated from pump, power characteristics equations as well as affinity law
and
reconstructed by polynomial best-fit based on the pump data published by pump
manufacturers. The converter is much easier to be set up while maintaining
satisfactory accuracy. Most importantly above all, there may be no need for
tedious
and time consuming instrumentation calibration process, as long as
manufacturers
published data or curves are available.
Figure 6:
By way of example, Figure 6 shows apparatus 10 according to some
embodiments of the present invention, e.g., featuring a signal processor or
processing module 10a configured at least to:
receive signaling containing information about motor readout values of
power and speed, and also about pump and system characteristics equations
together with empirical power equations that are constructed by a polynomial
best-fit function together with pump affinity laws based upon a pump curve
published by a pump manufacturer; and
determine corresponding signaling containing information about a
pump or system pressure and a flow rate at the motor readout values of
power and speed, based upon the signaling received.
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In operation, the signal processor or processing module may be configured to
resolve pump differential pressures and flow rate at an equilibrium point of
the pump
or system pressure at a motor steady state condition.
In operation, the signal processor or processing module 10a may also be
configured to provide corresponding signaling containing information about the
pump
or system pressure and the flow rate, including for pump differential pressure
and
flow monitoring. The corresponding signaling may be used to control a hydronic
pumping system.
As a person skilled in the art would appreciate and understand, the present
invention may be implemented using pump and system characteristics equations
and empirical power equations, e.g., consistent with that set forth herein, as
well as
by using other types or kinds of pump and system characteristics equations and
empirical power equations that are either now known or later developed in the
future.
As a person skilled in the art would appreciate and understand, the present
invention may be implemented using pump curves published by pump
manufacturers, e.g., consistent with that set forth herein that are known in
the art for
pumps that are also known in the art at the time of the present invention.
However,
embodiments are envisioned, and the scope of the invention is intended to
include,
using other types or kinds of pump curves published by pump manufacturers for
pumps that are later developed after the time of the present invention.
By way of example, the functionality of the apparatus 10 may be implemented
using hardware, software, firmware, or a combination thereof. In a typical
software
implementation, the apparatus 10 would include one or more microprocessor-
based
architectures having, e. g., at least one signal processor or microprocessor
like
element 10a. A person skilled in the art would be able to program such a
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microcontroller-based, or microprocessor-based, implementation to perform the
functionality described herein without undue experimentation. For example, the
signal processor or processing module 10a may be configured, e.g., by a person
skilled in the art without undue experimentation, to receive the signaling
containing
information about the motor readout values of power and speed, and also about
the
pump and system characteristics equations together with the empirical power
equations that are constructed by the polynomial best-fit function together
with the
pump affinity laws based upon the pump curve published by the pump
manufacturer,
consistent with that disclosed herein. By way of example, the information
about the
motor readout values of power and speed may be included in sensed signaling
received, processed and/or stored, e.g., in a suitable memory module that
forms part
of such a microprocessor-based architecture. Similarly, by way of example, the
information about the pump and system characteristics equations together with
the
empirical power equations that are constructed by the polynomial best-fit
function
together with the pump affinity laws based upon the pump curve published by
the
pump manufacturer may be received, processed and/or stored, in a suitable
memory
module that forms part of such a microprocessor-based architectures.
Moreover, the signal processor or processing module 10a may be configured,
e.g., by a person skilled in the art without undue experimentation, to
determine the
corresponding signaling containing information about a pump or system pressure
and a flow rate at the motor readout values of power and speed, based upon the
signaling received, consistent with that disclosed herein.
The scope of the invention is not intended to be limited to any particular
implementation using technology either now known or later developed in the
future.
The scope of the invention is intended to include implementing the
functionality of
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the processors 10a as stand-alone processor or processor module, as separate
processor or processor modules, as well as some combination thereof.
The apparatus 10 may also include, e.g., other signal processor circuits or
components 10b, including random access memory or memory module(RAM) and/or
read only memory (ROM), input/output devices and control, and data and address
buses connecting the same, and/or at least one input processor and at least
one
output processor.
Various Points of Novelty
The present invention may include, or take the form of, one or more of the
following various embodiments:
For example, according to some embodiments the present invention may take
the form of, or may be implemented as, a best-fit affinity sensorless
conversion
means or technique for pump differential pressure and flow, e.g., that may
include a
pump sensorless converter which yields the pump differential pressure and
system
flow rate associated with a dynamic system with respect to motor speed and
power
readout signals based on the pump and system characteristics curves equations
together with the empirical power equations represented as P ¨ f (Q, n),
P=(QICõ)2and W = w(Cõ, n), e.g., as schematically plotted in Figure 3.
According to some embodiments, the present invention may be implemented
using one preferred version of the best-fit affinity sensorless conversion
means or
technique for pump differential pressure and flow mentioned above, e.g., may
include a solution of pump differential pressure, or system pressure, and flow
rate at
the steady state equilibrium point of the pump differential pressure and
system
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pressure, which is the intersection of the pump and system curves
schematically
shown.
According to some embodiments, the present invention may be implemented
using the pump curves equations in the best-fit affinity sensorless conversion
means
or technique mentioned above, e.g., that may include pump curve models which
are
developed based upon the pump characteristics equations at a motor speed and
system flow rate. The pump curve models mentioned here may be expressed
approximately by function of P = f (Q , n) based upon the pump hydronic
characteristic curve at full speed (or pump curve) and pump affinity law. For
a
reasonably good representation with high accuracy, the best-fit approach may
be
used to formulate the pump curve function of P = f (Q ,n). For instance, a
second
order best-fit affinity polynomial function of
2 1
P (n, Q) = (L) (a (nmax)2 Q2 b (nmax) Q + c) may be used for representing a
pump curve at a speed of n. For a pump characteristics curve with a little
complicated curve shape, however, a higher order polynomial expression may be
used to better represent pump curve, if achievable. Some other expressions may
be
obtained as well if other kinds of curve fitting or interpolating approaches
are used
alternatively. Curve fitting or interpolating approaches are known in the art,
and the
scope of the invention is not intended to be limited to any particular type or
kind
thereof either now known or later developed in the future.
According to some embodiments, the present invention may be implemented
using the equivalent hydronic system characteristics curve equation in the
best-fit
affinity sensorless conversion means or technique mentioned above, e.g., that
may
include the flow equation of Cõ = Q/Arii, or some of its alternative
expressions or
approximations, to represent the system characteristics curve.
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According to some embodiments, the present invention may be implemented
using the steady state pressure equilibrium point in the best-fit affinity
sensorless
conversion means or technique mentioned above, that may include the
intersection
point of the pump and system curves functions, as shown in Fig. 3. The system
pressure or pump differential pressure and flow rate may be solved at the
pressures
equilibrium point for a pair of motor readout values given, for instance,
speed and
power, as the sensorless output values converted. For instance, for a second
order
best-fit affinity pump curve approximation, the aforementioned Eqs. 1 and 2
presented as
2nmn ax( b -jb2-4c'(a C';-2))
Q (n, Cy) -= ____________________________________ (1)
and
2
1)(n , Q) = (n)2 (n") Q2 + b __ Q + c) (2)
ninn.x
may be the system flow rate and pressure expressions derived for the
sensorless
converter at a pair of motor speed and power given, respectively. The
equations for
converting the system pressure and flow rate may be written in some other
forms as
well by following the stead state pressure equilibrium point approach,
however, in
case that the higher order fitting or interpolating functions or some other
forms of
functions are used, if desirable.
According to some embodiments, the present invention may be implemented
using the empirical power function to resolve the equivalent system
characteristics
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coefficient with respect to motor power and speed in the best-fit affinity
sensorless
conversion means or technique mentioned above, e.g., that may include the
empirical power function of w(C,,n) with respect to motor speed and system
flow
rate. The power curve models mentioned here may be expressed approximately by
function of w(c,n) based upon the power curve at full speed, exactly
corresponded
to the pump curve, and affinity law. For a reasonably good representation with
high
accuracy, similarly, the best-fit affinity approach may be used to formulate
the power
curve function of f w(C,, n). For instance, a second order best-fit affinity
polynomial
function of Eq. 4,
2 B2
w(c, n) = n ________ )3 B (A (cwrm + 2A)2 + (c _)),P = Põ n õ d s
Q (4)
nrrtax nmax Q4i
may be used for representing a power curve function in term of motor speed of
n and
the normalized equivalent system characteristics coefficient of co-, based
upon
the corresponding power curve associated with the pump curve at maximum speed,
schematically plotted in Figure 4. A higher polynomial expression or other
form
expressions may be introduced as well for better representing power curve
functions,
if needed.
According to some embodiments, the present invention may be implemented
using one preferred version of the empirical power function in the best-fit
affinity
sensorless conversion means for pump differential pressure and flow mentioned
above, e.g., that may include a best-fit affinity polynomial function of the
Equation
(4):
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B2
w(C.,,,n) = r (n)(A (qui"' + 2+ (C. ¨ ) -4-
¨
4A)- )
with the modified power affinity law of f * (n) in form of the third order
polynomial
expression of Equation (6) as:
f * (n) = (14.1 (n nmax)3 + (n/nmax)2 C'(n/n,,,,)1 D'). (6)
The modified power affinity law of f(n) is obtained by fitting an array of
power
values normalized at its corresponding maximum value at full speed with a set
of
given speeds at a given system position ,which may be used to compensate the
power variation at low speed region with system shut down.
According to some embodiments, the present invention may be implemented
using the system characteristics coefficient conversion in the best-fit
affinity
sensorless conversion means or technique, e.g., that may include all forms of
expressions either a close form solution or a solution using some discrete
numerical
methods. For example, Equation 3 of
jw (flmaxfl )3 (C 4-BA2)
C7r7" (w ¨ ¨2A +
A
(3)
may be close form solutions derived inversely for the equivalent system
characteristics coefficient expression by using empirical power function of
Eq. 4.
According to some embodiments, the present invention may be implemented
using the hydronic pumping system in the best-fit affinity sensorless
conversion
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means or technique, e.g., that may include all close loop or open loop
hydronic
pumping systems, such as primary pumping systems, secondary pumping systems,
water circulating systems, and pressure booster systems. The systems mentioned
here may consist of a single zone or multiple zones as well.
According to some embodiments, the present invention may be implemented
using the pump and power curves data at motor maximum speed in the best-fit
affinity sensorless conversion means or technique, e.g., that may include the
pump
and power curves data published by pump manufacturers or a few points of pump
data acquired at motor full speed in field, Here, the motor power curve data
may
also be replaced by any potential motor electrical or mechanical readout
signals,
such as motor current or torque, and so forth.
According to some embodiments, the present invention may be implemented
using the hydronic signals for in the best-fit affinity sensorless conversion
means or
technique, e.g., that may include pump differential pressure, system pressure
or
zone pressure, system or zone flow rate, and so forth.
According to some embodiments, the present invention may be implemented
using control signals transmitting and wiring technologies, e.g., that may
include all
conventional sensing and transmitting means that are used currently.
Preferably,
wireless sensor signal transmission technologies would be optimal and
favorable.
According to some embodiments, the present invention may be implemented
using the pumps mentioned above for the hydronic pumping systems, e.g., that
may
include a single pump, a circulator, a group of parallel ganged pumps or
circulators,
a group of serial ganged pumps or circulators, or their combinations.
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According to some embodiments, the present invention may be implemented
using systems flow regulation, e.g., that may include manual or automatic
control
valves, manual or automatic control circulators, or their combinations.
The aforementioned implementations are provided by way of example, and
the scope of the invention is intended to include other types or kinds of
implementations consistent with that disclosed herein within the spirit of the
present
invention.
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The Scope of the Invention
It should be understood that, unless stated otherwise herein, any of the
features, characteristics, alternatives or modifications described regarding a
particular embodiment herein may also be applied, used, or incorporated with
any
other embodiment described herein. Also, the drawings herein are not drawn to
scale.
Although the present invention is described by way of example in relation to a
centrifugal pump, the scope of the invention is intended to include using the
same in
relation to other types or kinds of pumps either now known or later developed
in the
future.
Although the invention has been described and illustrated with respect to
exemplary embodiments thereof, the foregoing and various other additions and
omissions may be made therein and thereto without departing from the spirit
and
scope of the present invention.
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