Pump Delivery Rate Determination via Probability Density Fusion

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Solution Overview

Problem

Existing methods for determining pump delivery flow, such as H(Q) and P(Q) characteristics, are prone to errors due to flat profiles and non-uniqueness, especially when dealing with pumps having characteristics that initially increase and then decrease, leading to large deviations in delivery flow measurements.

Innovation Solution

The method involves calculating probability density functions for delivery head and power, fusing data from these functions to minimize errors, and using sensors to determine pressure differences and motor actuation frequency, with an electronic evaluation unit processing the data to provide accurate and stable delivery flow values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If indirect methods using H(Q) or P(Q) characteristics are used to determine delivery flow, then measurement cost is reduced, but measurement precision deteriorates due to flat profiles and non-uniqueness

Engineering Contradiction:
Improvemeasurement costVSAvoiddelivery flow measurement precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The invention combines both H(Q) and P(Q) characteristics into a unified evaluation system. By merging the information from both characteristics and their respective probability density functions, the system achieves more reliable delivery flow determination than either characteristic alone, especially for pumps with flat characteristics.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention transforms the deterministic characteristic curves into probability density functions, changing the parameter representation from fixed values to probabilistic distributions. This allows for a more robust evaluation that accounts for uncertainties and flat profiles in the original characteristics.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If H(Q) characteristics with flat profiles are used, then device complexity is reduced, but reliability deteriorates due to large errors in delivery flow determination

Engineering Contradiction:
Improvemeasurement system complexityVSAvoiddelivery flow determination reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system uses feedback from both H(Q) and P(Q) characteristics to continuously refine the delivery flow determination. By evaluating both characteristics and their probability density functions, the system provides mutual validation and correction, improving reliability without significantly increasing complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The invention creates a composite evaluation system that combines H(Q) and P(Q) characteristics, similar to how composite materials combine different materials to achieve superior properties. The combined system leverages the strengths of both characteristics while compensating for their individual weaknesses.

Inventive Principle:
Principle #40Composite materials

3Measurement precision

If direct measurement using magnetic inductive flow meters is used, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedelivery flow measurement precisionVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention introduces probability density functions as intermediaries between the measured parameters (delivery head and power) and the delivery flow determination. These probability density functions serve as mediators that transform the characteristic curves into a form that can be reliably evaluated, achieving precision comparable to direct measurement without the associated complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS10352324B2Determining the delivery rate of a pump
Publication Date: 2019.07.16 KSB SE & CO KGAA
  • US10352324B2 patent drawing
  • US10352324B2 patent drawing

AI summary

The invention relates to a method for determining the delivery rate of a pump. In this context, a value of the delivery level and a value of the power of the pump are determined. A probability density function is calculated for the delivery level and the power. A first probability density function of the delivery rate is calculated on the basis of a delivery level-delivery rate relationship and the probability density function of the delivery level. A second probability density function of the delivery rate is determined on the basis of a power-delivery rate relationship and the probability density function of the power. A combined probability density function of the delivery rate is determined on the basis of the first and second probability density functions. The delivery rate is determined on the basis of the combined probability density function.