Best-fit affinity sensorless conversion means or technique for pump differential pressure and flow monitoring

Patent metadata

Field	Value
Publication number	US-9938970-B2
Application number	US-201514680667-A
Country	US
Kind code	B2
Filing date	Apr 7, 2015
Priority date	Dec 16, 2011
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

The present invention provides apparatus, including a hydronic sensorless pumping system, that features a signal processor or processing module configured 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.

First claim

What we claim is:

1. Apparatus for pump differential pressure and flow monitoring, comprising:
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
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.

2. Apparatus according to claim 1 , wherein the signal processor or processing module is 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.

3. Apparatus according to claim 1 , wherein the signal processor or processing module is configured to provide the corresponding signaling containing information about the pump or system pressure and the flow rate, including for pump differential pressure and flow monitoring.

4. Apparatus according to claim 3 , wherein the corresponding signaling contains information used to control a hydronic pumping system.

5. Apparatus comprising:
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
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, wherein the signal processor or processing module is configured to:
resolve the pump or system pressure and the flow rate at a steady state equilibrium point of pump and system pressures which is at an intersection of pump and system curves functions determined,
determine or represent an instant pump characteristic curve, which is the pump differential pressure P with respect to flow rate Q and motor speed of n, using an approximation in a polynomial form of P=f(Q,n) based upon a pump curve at a motor full speed n max as well as the pump affinity laws, and
resolve a system flow rate by using a pump differential pressure function of P=f(Q,n) together with the system flow equation of C v =Q/√{square root over (P)} subsequently.

6. Apparatus according to claim 5 , wherein the signal processor or processing module is configured to use the pump affinity laws denoted by the equations for pump flow, differential pressure and motor power, as follows:
Q/Q max =n/n max , P/P max =(n/n max ) 2 and, w/w max =(n/n max ) 3 , respectively.

7. Apparatus according to claim 6 , wherein the signal processor or processing module is configured to derive the system flow rate, using a second order best-fit affinity pump curve function together with a system flow equation as follows:

Q
⁡

(

n
,

C
v

)

=

n

2
⁢

n

ma
⁢

⁢
x

⁢

(

-
b

±

b
2

-

4
⁢

c
⁡

(

a
-

C
v

-
2

)

)

/

(

a
-

C
v

-
2

)

,

(
1
)

where C v is the system coefficient, and a, b and c are the coefficients of the second order best-fit affinity pump curve function at motor full speed of n max .

8. Apparatus according to claim 7 , wherein the signal processor or processing module is configured to use a pump differential pressure function of P=f(Q,n) in the form of Equation (2) as follows:
P ( n,Q )=(α Q 2 +b ( n/n max ) 1 Q +( n/n max ) 2 c ).

9. Apparatus according to claim 8 , wherein the signal processor or processing module is configured to reconstruct a motor power function at maximum speed with respect to the system coefficient by using a fitting o

Assignees

• Fluid Handling Llc
• Fluid Handling Llc

Inventors

• Cheng Andrew A
• Gu James J
• Scott Graham A

Classifications

• F04B49/106

  Responsive to pumped volume · CPC title

• F04B49/065

  and making use of computers · CPC title

• F16K37/0075

  For recording or indicating the functioning of a valve in combination with test equipment · CPC title

• G01L5/0061

  Force sensors associated with industrial machines or actuators (for the specific machine or actuator involved see relevant class, e.g. F01, F04, F16, B66, E21) · CPC title

• F15B19/00

  Testing; {Calibrating; Fault detection or monitoring; Simulation or modelling of} fluid-pressure systems or apparatus not otherwise provided for · CPC title