Multi-Pump Control Using Power and Speed Without Flow Sensors

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Solution Overview

Problem

Existing multi-pump control systems require pre-knowledge of pump characteristics and measurement of pressure differential and flow to determine an energy-efficient number of running pumps, which is time-consuming and not feasible in dynamic conditions.

Innovation Solution

A control system that uses a processing module to determine approximated pump characteristics based on power consumption and speed signals, without measuring pressure differential or flow, by scaling flow and pressure to reduce parameters and optimize energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If stored pre-knowledge of pump characteristics is used, then energy-efficient operation can be determined, but the system cannot adapt to changes in real pump characteristics due to manufacturing tolerances, wear and fouling

Engineering Contradiction:
Improveaccuracy of pump characteristicsVSAvoidadaptability to pump characteristic changes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The control system performs self-characterization by automatically determining pump characteristics through configuration cycles with different pump subsets, eliminating the need for external pre-knowledge and enabling automatic adaptation to actual pump performance

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from pressure differential measurements and power consumption data to iteratively refine and update pump characteristics, allowing continuous adaptation to changing pump conditions due to wear, fouling, or manufacturing variations

Inventive Principle:
Principle #23Feedback

2Measurement precision

If several configuration cycles are run to find the best subset of pumps, then accurate pump characteristics can be determined, but significant time is consumed and pressure differential measurement is required

Engineering Contradiction:
Improveaccuracy of pump characteristicsVSAvoidtime for configuration cycles
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The invention extracts and uses power consumption data as an additional measurement parameter alongside pressure differential, enabling more accurate pump characteristic determination without requiring extended configuration cycles or solely relying on pressure measurements

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary characterization during normal operation by continuously monitoring power consumption and pressure differential, so that accurate pump characteristics are available without requiring separate time-consuming configuration cycles

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If pressure differential measurement is used to determine optimal pump operation, then accurate characteristics can be obtained, but the system becomes complex and requires continuous monitoring

Engineering Contradiction:
Improveaccuracy of pressure differentialVSAvoidmeasurement and monitoring system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control system performs multiple functions using the same measurement infrastructure: it uses pressure differential and power consumption measurements both for real-time optimal pump subset determination and for continuous pump characteristic characterization, eliminating the need for separate monitoring systems

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3940237B1Multi-pump control system
Publication Date: 2022.08.24 GRUNDFOS HLDG
  • EP3940237B1 patent drawingFigure 1
  • EP3940237B1 patent drawingFigure 2
  • EP3940237B1 patent drawingFigure 3A~3B

AI summary

The present disclosure provides a multi-pump control system (5) comprising - a control module (7), - a processing module (9), - a communication interface (11), and - a storage module (13), wherein the control module (7) is configured to change a number n of running pumps of a multi-pump system (3), wherein the communication interface (11) is configured to receive a signal indicative of a power consumption P and information about a speed ω of at least one of the n running pumps before and after at least two different changes of the number n of running pumps, wherein the processing module (9) is configured to determine, before and after at least two different changes of the number n of running pumps, in absence of a measurement of a differential pressure Δp and of a flow Q, at least two approximated pump characteristics Pn and Δp̃n, wherein each of the approximated pump characteristics Pn and Δp̃n is unambiguously defined by a pair of parameters (θ1, θ2; θ3, θ4), wherein the storage module (13) is configured to store the pair of parameters (θ1, θ2; θ3, θ4) for each of the determined approximated pump characteristics Pn and Δp̃n.