Direct numeric affinity pumps sensorless converter

Patent metadata

Field	Value
Publication number	US-2016356276-A1
Application number	US-201615173781-A
Country	US
Kind code	A1
Filing date	Jun 6, 2016
Priority date	Jun 4, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

The present invention provides a numerical affinity pump sensorless conversion signal processing technique, e.g. based upon processing the pump differential pressure, flow rate and power at pump maximum speed published by pump manufacturers, as well as the pump affinity law in order to obtain instant pump differential pressures and flow rate directly and numerically. The sensorless converter technique may be applied to any form of pump characteristics distributions simple or complicated, since there is no need to reconstruct and to solve any pump and system characteristics equations. As a result, the computation accuracy is significantly improved.

First claim

What we claim is:

1 . Apparatus comprising:
a signal processor or processing module configured at least to:
receive signaling containing information about pump differential pressure, flow rate and corresponding power data at motor maximum speed published by pump manufacturers, as well as instant motor power and speed; and
determine corresponding signaling containing information about instant pump differential pressure and flow rate using a combined affinity equation and numerical interpolation algorithm, based upon the signaling received.

2 . Apparatus according to claim 1 , wherein the signal processor or processing module is configured to provide the corresponding signaling to control a pump in a pumping system, e.g., such as a hydronic pumping system.

3 . Apparatus according to claim 1 , wherein the signal processor or processing module is configured to determine the corresponding signaling by implementing the combined affinity equation and numerical interpolation algorithm as follows:
obtaining a corresponding maximum power at the pump's maximum speed with respect to the instant motor power and speed parameters using a power affinity equation; obtaining corresponding pump differential pressure and flow rate with respect to the corresponding maximum power at the pump's maximum speed using direct numerical interpolation; and determining the instant pump differential pressure and flow rate with respect to the instant motor speed and power by using pressure and flow affinity equations.

4 . Apparatus according to claim 3 , wherein the signal processor or processing module is configured to determine the instant pump differential pressure and flow rate by implementing the combined affinity equation and numerical interpolation algorithm and using numerical computation procedures as follows:

Q


(

n
,
w

)

=

(

n

n
max

)

·

q
_



(

n
max

,

W
i

,

Q
i

,

w
^



(

n
,
w

)

)

,

(
1
)

P


(

n
,
w

)

=

(

n

n
max

)

2

·

p
_



(

n
max

,

W
i

,

P
i

,

w
^



(

n
,
w

)

)

,

(
2
)

where q (n max , W i , Q i , ŵ) and p (n max , W i , P i , ŵ) are pump differential pressure and flow rate distribution functions with respect to power and formulated numerically based upon discrete pump data of (P i , Q i , W i ) at motor full speed, and ŵ is a corresponding power function at pump full speed by the power affinity equation of
{circumflex over ( w )}( n,w )=( n/n max ) −3 ·w.   (3)

5 . Apparatus according to claim 1 , wherein the apparatus comprises a pump controller configured with the signal processor or processing module.

6 . Apparatus according to claim 1 , wherein the apparatus comprises a hydronic

Assignees

• Fluid Handling Llc

Inventors

• Cheng Andrew A
• Gu James J
• Schoenheit Kyle D

Classifications

• F04D15/0077

  Safety measures (F04D15/02 takes precedence) · CPC title

• F04B1/34

  Control not provided for in groups F04B1/02, F04B1/03, F04B1/06 or F04B1/26 · CPC title

• F04B2205/09

  Flow through the pump · CPC title

• F05D2270/335

  Output power or torque · CPC title

• F04B2205/07

  Pressure difference over the pump · CPC title