Heat Exchanger Fluid Flow Synchronization for Fan Speed Energy Control

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Solution Overview

Problem

HVAC systems face inefficiencies in energy consumption when users reduce fan speed to avoid drafts, as the existing systems do not adjust the flow of heat carrying fluid accordingly, leading to suboptimal operation of heat influencing sources and increased energy use.

Innovation Solution

A method where the fan speed adjustment is synchronized with the flow of heat carrying fluid through the heat exchanger to maintain a predetermined temperature difference, using a valve actuated by a fan speed selection device or room controller, ensuring optimal operation of heat sources and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the fan speed is reduced to avoid drafts, then user comfort is improved, but energy consumption increases because the heat carrying fluid flow is not adjusted accordingly

Engineering Contradiction:
Improvedraft discomfortVSAvoidenergy consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the heat carrying fluid flow rate in response to fan speed changes. When the fan speed is reduced to minimize drafts, the control system simultaneously reduces the heat carrying fluid flow through the heat exchanger to match the reduced heat transfer demand, preventing energy waste while maintaining user comfort.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system monitors fan speed and uses this information to adjust the heat carrying fluid flow rate accordingly. This feedback mechanism ensures that the heat influencing source operates at an optimal point by matching the fluid flow to the actual heat transfer requirements determined by the fan's air movement capacity.

Inventive Principle:
Principle #23Feedback

2Reliability

If the flow of heat carrying fluid is maintained at high level when fan speed is reduced, then heat exchanger performance is maintained, but energy consumption increases and heat influencing source operates suboptimally

Engineering Contradiction:
Improveheat exchanger performanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the heat carrying fluid flow rate in response to fan speed changes. When the fan speed is reduced to minimize drafts, the control system simultaneously reduces the heat carrying fluid flow through the heat exchanger to match the reduced heat transfer demand, preventing energy waste while maintaining user comfort.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system changes the operating parameters of the heat influencing source by adjusting the heat carrying fluid flow rate based on fan speed. This ensures the heat influencing source operates at its optimal point by matching the fluid flow to the actual heat transfer requirements, thereby maintaining efficiency while reducing energy consumption.

Inventive Principle:
Principle #35Parameter changes

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 maintains a constant temperature difference across the heat exchanger, optimizing the operation of heat sources and reducing energy consumption by adjusting the fluid flow in response to fan speed changes, particularly beneficial for district heating systems and condensing gas boilers.

Implementation Method 1

a heat exchanger connected to a supply pipe arrangement and a fan for generating an air stream through the heat exchanger, wherein a flow of a heat carrying fluid is guided through the heat exchanger

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP4332454A1Method for controlling a temperature influencing system and temperature influencing system
Publication Date: 2024.03.06 DANFOSS AS
  • EP4332454A1 patent drawingFigure 1~2
  • EP4332454A1 patent drawingFigure 3~4
  • EP4332454A1 patent drawing

AI summary

A method for controlling a temperature influencing system (1) having a heat exchanger (2) connected to a supply pipe arrangement (3) and a fan (7) for generating an air stream (8) through the heat exchanger (2) is described, wherein a flow of a heat carrying fluid is guided through the heat exchanger (2) and a user can change the speed of the fan (7). Such a method should work with low energy consumption. To this end, when the user changes the speed of a fan (7) at the same time the flow of the heat carrying fluid through the heat exchanger (2) is adjusted to a size in which a temperature difference over the heat exchanger (2) is maintained at a predetermined value.