Circulation Pump Medium Temperature Estimation via Winding Current

Solution Overview

Problem

Existing heating circulating pumps require additional temperature sensors to determine the medium temperature, increasing design effort and costs, and this information is needed not only for night setback but also for temperature-controlled regulation and calcification detection.

Innovation Solution

The method calculates the pumped medium temperature using the temperature and current of the motor winding, eliminating the need for an additional sensor by employing an observer function within the pump control that simulates pump behavior with low-pass filters modeling the relationship between winding current, winding temperature, and medium temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an additional temperature sensor is integrated into the circulating pump to determine the medium temperature, then the temperature measurement capability is improved, but the design effort and manufacturing costs increase

Engineering Contradiction:

Improvemedium temperature measurementVSAvoiddesign effort and manufacturing costs

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The circulating pump uses its own motor winding temperature measurement and motor model to determine the medium temperature, rather than relying on an additional dedicated temperature sensor. The motor's inherent temperature sensing capability is leveraged to provide medium temperature information through computational estimation, making the system self-sufficient.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The motor winding temperature measurement serves dual purposes: monitoring motor health and determining medium temperature. The existing motor components (windings, temperature sensors) are utilized for multiple functions, eliminating the need for dedicated single-purpose components and reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If an additional temperature sensor is integrated into the circulating pump to determine the medium temperature, then the temperature measurement capability is improved, but the manufacturing costs increase

Engineering Contradiction:

Improvemedium temperature measurementVSAvoidmanufacturing costs

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The circulating pump uses its own motor winding temperature measurement and motor model to determine the medium temperature, rather than relying on an additional dedicated temperature sensor. The motor's inherent temperature sensing capability is leveraged to provide medium temperature information through computational estimation, making the system self-sufficient.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The solution replaces an additional expensive temperature sensor with computational estimation using existing motor parameters. The approach uses readily available motor data (winding resistance, current, voltage) and standard motor models to calculate medium temperature, avoiding the cost of additional sensing hardware.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Use of energy by moving object

If the circulating pump performance is coupled to the night reduction to achieve energy savings, then the energy efficiency is improved, but the pump needs additional information about the current heating mode

Engineering Contradiction:

Improvepump energy efficiencyVSAvoidheating mode information

Core Design Contradiction:

Use of energy by moving objectVSLoss of information

Solution Approach 1:

The solution replaces the need for additional sensors or communication interfaces with a computational approach. By using the motor's electrical parameters (current, voltage, power factor) and thermal model, the system derives heating mode information through calculation rather than direct measurement, eliminating the need for extra information gathering hardware.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach provides accurate medium temperature information without additional sensors, enabling energy optimization, night setback detection, and calcification monitoring, while reducing manufacturing costs and design complexity.

Implementation Method 1

The winding current causes the windings to heat up due to copper losses

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the conveyed medium has an influence on the temperature of the windings of the pump unit. As a rule, the conveyed medium has a cooling effect on the windings

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentEP3593103B1Method for determining the temperature of the conveyance medium in a circulation pump, and circulation pump

Publication Date: 2022.03.30 KSB SE & CO KGAA

Figure 1~2
Figure 3

AI summary

The invention relates to a method for determining the temperature of the conveyed medium of a circulation pump, in particular a heating circulation pump, having an integrated electric drive unit, the temperature of the conveyance medium being determined or calculated on the basis of the winding temperature of the electric pump unit and the winding current that is present.