Hydronic Flow Control Module for Low ΔT Syndrome Prevention

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Solution Overview

Problem

Hydronic systems often suffer from the 'low ΔT syndrome' due to mismatched temperature differentials between primary and secondary loops, leading to inefficient operation, especially when new components are added or existing ones are not designed for the intended differential.

Innovation Solution

A flow control module that automatically calibrates temperature measurements and continuously adjusts the thermal power supply and demand by controlling primary and secondary side flows using controllable actuators, minimizing signed deviation values to maintain efficient operation regardless of unknown or varying design temperature differentials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If event-based triggered re-adjustment of temperature differential supply setpoint is used, then the low ΔT syndrome is addressed, but the system complexity and control difficulty increase

Engineering Contradiction:
Improvesystem operation stabilityVSAvoidcontrol mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system automatically detects flow imbalances and adjusts the temperature differential supply setpoint without external intervention. The control mechanism monitors temperature differences and flow rates, then self-corrects by adjusting the setpoint when deviations are detected, eliminating the need for manual recalibration after component changes.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system continuously monitors temperature differential and flow rate parameters, comparing actual values against target values. When deviations indicating low ΔT syndrome are detected, the feedback loop triggers automatic adjustment of the temperature differential supply setpoint to restore optimal operation.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If manual recalibration after component changes is required, then measurement accuracy is maintained, but loss of time and reduced productivity occur

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidsystem downtime for recalibration
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs automatic detection and adjustment of temperature differential deviations before they significantly impact system performance. By continuously monitoring and proactively adjusting the supply setpoint, the system prevents measurement drift and maintains accuracy without requiring periodic manual recalibration shutdowns.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control mechanism automatically compensates for measurement drift and calibration errors by detecting flow imbalances and adjusting operating parameters. This self-calibration capability eliminates the need for manual intervention to maintain measurement precision.

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If fixed design temperature differential is used, then system design is simplified, but adaptability to varying thermal power demands is reduced

Engineering Contradiction:
Improvesystem design simplicityVSAvoidadaptation to thermal power demand changes
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The system transitions from a fixed design temperature differential to a dynamic, adjustable setpoint. The temperature differential supply setpoint automatically varies based on real-time monitoring of flow rates and temperature differences, allowing the system to adapt to changing thermal power demands while maintaining optimal efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control mechanism changes the temperature differential parameter dynamically by adjusting the supply setpoint in response to detected flow imbalances. This parameter adaptation allows the system to maintain optimal temperature differential even when thermal power demands or system components change.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3751381B1Flow control module and method for controlling the flow in a hydronic system
Publication Date: 2022.07.27 GRUNDFOS HLDG
  • EP3751381B1 patent drawingFigure 1~1b
  • EP3751381B1 patent drawingFigure 2
  • EP3751381B1 patent drawingFigure 3

AI summary

The present disclosure is directed to a flow control module (39) for controlling one or more pumps in a hydronic system (1), wherein the hydronic system (1) comprises - a primary side (3) with a first port (21) in fluid connection with an output (23) of at least one source element (7), a second port (27) in fluid connection with an input (29) of the at least one source element (7), and at least one controllable primary side flow actuator (9) for providing a primary side flow (q1), - a secondary side (5) with a third port (31) in fluid connection with an input (33) of at least one load element (11), a fourth port (35) in fluid connection with an output (37) of the at least one load element (11), and at least one controllable secondary side flow actuator (13) for providing a secondary side flow (q2), and - an intermediary transfer element (17) between the primary side (3) and the secondary side (5), wherein the intermediary transfer element (17) is in fluid connection with the first port (21), the second port (27), the third port (31) and the fourth port (35). The flow control module (39) is configured to calibrate a measurement of a first temperature differential (ΔTc) between a temperature at the first port (21) and a temperature at the third port (31) in a first situation when the primary side flow (q1) exceeds the secondary side flow (q2), and in that the flow control module (39) is configured to calibrate a measurement of a second temperature differential (ΔTh) between a temperature at the fourth port (21) and a temperature at the second port (31) in a second situation when the secondary side flow (q2) exceeds the primary side flow (q1).