Circulating Pump Control via Valve Switching Detection

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Solution Overview

Problem

Existing circulating pumps in systems with multiple circulation circuits struggle to automatically recognize and adapt to switching processes between these circuits without signal communication, leading to inefficient operation and potential system faults.

Innovation Solution

The method involves detecting pressure and flow rate curves or electrical variables of the motor to identify switching processes and positions, allowing the pump to automatically adjust its operation to optimize performance across different circuits, using hydraulic and electrical data to determine the optimal operating point without external communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a pressure sensor is used to detect switching processes in multi-circuit heating systems, then the pump can be automatically reversed to match the active circuit, but the device complexity and cost increase due to additional sensors and communication requirements

Engineering Contradiction:
Improveautomatic pump reversalVSAvoidsensor and communication system
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The pump controller independently detects switching processes by monitoring its own motor's electrical variables (current, power, torque) and hydraulic parameters (pressure, flow rate), eliminating the need for external sensors or communication systems. The controller uses these self-measured parameters to automatically recognize circuit switching and reverse the pump direction accordingly.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces mechanical/electronic sensing systems (pressure sensors, communication protocols) with electrical measurement of motor variables. By monitoring changes in motor current, power consumption, and torque during switching transitions, the system detects circuit changes without additional hardware sensors.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the pump operates at fixed speed, then the control system is simple, but the pump cannot efficiently adapt to different circuit requirements and varying heat demands

Engineering Contradiction:
Improvepump speed adaptationVSAvoidcontrol system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The pump system transitions from fixed speed to variable speed operation through frequency converter control. The controller dynamically adjusts the pump speed based on real-time analysis of motor electrical variables and hydraulic parameters, enabling the pump to adapt its operating point to match different circuit requirements and heat demands while maintaining optimal efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the pump by adjusting motor frequency and voltage through a frequency converter. This allows continuous variation of pump speed and flow rate according to the detected circuit state and heat demand, optimizing system performance across different operating conditions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If separate signal communication is implemented between the controller and pump for circuit switching information, then the pump can respond accurately to circuit changes, but the system complexity and cost increase

Engineering Contradiction:
Improvecircuit switching detectionVSAvoidcommunication system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pump controller acts as an intermediary that indirectly detects circuit switching events through monitoring changes in motor electrical variables and hydraulic parameters. Instead of receiving direct switching signals, the controller infers circuit changes from the physical response of the motor-pump system to the switching event, using these measurements as mediators to detect the actual circuit state.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If manual adjustment is required for pump operation in multi-circuit systems, then the control system remains simple, but the pump cannot automatically adapt to different circuits leading to inefficient operation

Engineering Contradiction:
Improveautomatic operationVSAvoidcontrol electronics
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The pump system performs self-adjustment by automatically detecting circuit switching through monitoring of motor electrical variables and hydraulic parameters. The controller independently determines the appropriate pump direction and speed settings based on these measurements, eliminating the need for manual intervention while maintaining system simplicity through the use of existing motor and pump components.

Inventive Principle:
Principle #25Self-service

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 enables automatic recognition and adaptation of switching processes, ensuring the pump operates efficiently and correctly across multiple circuits, even in complex heating systems, and can be easily integrated into existing systems through software updates, enhancing reliability and adaptability.

Implementation Method 1

with an electric motor (10) for driving the centrifugal pump (1)

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a centrifugal pump (1) having a shaft (2) for rotating about a rotation axis (L)

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2708825B1Method for controlling a circulating pump in an assembly with at least two circuits
Publication Date: 2016.12.07 GRUNDFOS HLDG
  • EP2708825B1 patent drawingFigure 1~2b
  • EP2708825B1 patent drawingFigure 3a~3b
  • EP2708825B1 patent drawingFigure 4a~4b

AI summary

The method involves controlling the circulation pump (1) based on the switching position of a switching valve (2). The switching position of the switching valve is determined by detecting the pressure variation and flow rate profile in the circulation pump or a dependent electrical variable of the motor. The control of the circulation pump is reversed based on the detection of switching operation. The shift position based on pressure profile and the flow rate gradient of the engine between successive switching operations is determined. An independent claim is included for a circulation pump assembly.