Pump Flow Rate Estimation Using Downstream Pressure Sensors

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing pump systems lack an accurate method to measure flow rate without using a flow meter, especially in transient or steady-state conditions, leading to inefficiencies and wear due to internal losses.

Innovation Solution

A passive method using two downstream pressure sensors placed at known distances from the pump, along with pipe characteristics, to estimate the flow rate through an iterative process and observer model, without the need for external flow rate sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a flow meter is used to measure flow rate accurately, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improveflow rate measurement accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses pressure sensors as intermediary devices to indirectly measure flow rate. Instead of directly measuring flow with a flow meter, the system measures pressure at two different locations downstream and uses the pressure differential as an intermediary parameter to calculate flow rate through fluid dynamics equations, thereby avoiding the need for complex and expensive flow meters

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical flow measurement devices (flow meters) with a computational approach using pressure measurements and mathematical models. The system substitutes direct mechanical flow sensing with indirect pressure-based calculation using the Darcy-Weisbach equation and iterative computational methods

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If pump characteristics are monitored to detect wear, then reliability is improved, but measurement precision deteriorates without flow rate information

Engineering Contradiction:

Improvepump wear detection capabilityVSAvoidflow rate information accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where pressure measurements are continuously taken and fed into an iterative calculation model that produces flow rate estimates. This feedback loop enables continuous monitoring of pump performance characteristics, allowing detection of wear and degradation over time by comparing measured flow rates against expected performance curves

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system uses the existing pump system's own pressure measurements and operational data to self-determine its performance status. By utilizing the pump's inherent pressure differential and flow characteristics, the system can autonomously monitor its own wear and efficiency without requiring external measurement devices

Inventive Principle:

Principle #25Self-service

3Measurement precision

If transient fluid wave injection is used to calculate wave speed and flow rate, then measurement precision is improved, but ease of operation worsens due to additional devices and conditions

Engineering Contradiction:

Improveflow rate measurement accuracyVSAvoidoperational simplicity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent enables continuous flow rate measurement during normal pump operation without interrupting the fluid flow or requiring transient disturbances. The system continuously measures pressure differential and calculates flow rate using steady-state or transient operating conditions, eliminating the need for periodic wave injection and maintaining uninterrupted operational usefulness

Inventive Principle:

Principle #20Continuity of useful action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method provides accurate flow rate estimation in any working condition of the pump, simplifying installation and reducing costs by eliminating the need for flow meters, while also enabling wear monitoring and predictive maintenance.

Implementation Method 1

by using pressure information coming from a first downstream pressure sensor placed on the downstream pipe at a first distance from the pump and a second downstream pressure sensor placed on the downstream pipe at a second distance from the pump

Methodology Applied

Scientific EffectPressure differential measurement: Pressure Gradient

Implementation Method 2

the friction loss coefficient F may be calculated based on a friction loss coefficient estimator model E2 defined by the equations

Methodology Applied

Scientific EffectFriction loss: Friction

Implementation Method 3

when the Reynolds coefficient Re of the flow in the downstream pipe is greater or equal than 2300

Methodology Applied

Scientific EffectReynolds coefficient:

Data Source

PatentUS20250035471A1Method for measuring of the flow rate of a pump

Publication Date: 2025.01.30 SCHNEIDER TOSHIBA INVERTER EUROPE SAS

AI summary

A method for estimating the output flow rate provided by a pump in a system including the pump, an upstream pipe and a downstream pipe, by using pressure information coming from a first downstream pressure sensor placed on the downstream pipe at a first distance from the pump and a second downstream pressure sensor placed on the downstream pipe at a second distance from the pump for calculating the output flow rate.