Variable-Speed Fan Pressure Control for Partial Airflow

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Solution Overview

Problem

Existing ventilation systems face challenges in efficiently regulating fan pressure, leading to energy overconsumption, acoustic issues, and leakage due to the mismatch between fan characteristics and network pressure drops, especially when operating at partial flow rates.

Innovation Solution

A method and device that continuously measure airflow and adjust fan speed based on a flow-pressure curve integrating network pressure drops, allowing for adaptive pressure regulation by calculating the required pressure and controlling fan rotation to match ventilation needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If the fan operates at constant speed to provide maximum pressure, then the pressure requirement is met, but energy consumption increases and acoustic performance deteriorates

Engineering Contradiction:
Improvefan pressureVSAvoidenergy consumption
Core Design Contradiction:
Stress or pressureVSUse of energy by moving object

Solution Approach 1:

The fan speed is made variable through an electronic control system that adjusts the motor speed based on actual ventilation requirements. The control unit receives feedback from pressure sensors and flow meters, dynamically adjusting the fan speed to match the required pressure level, thereby avoiding continuous operation at maximum speed and reducing energy consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements a closed-loop control with feedback from pressure sensors positioned in the ventilation network and flow meters. These sensors continuously monitor the actual pressure and flow conditions, sending signals to the electronic control unit which adjusts the fan speed accordingly, creating a self-regulating system that optimizes energy usage while maintaining required pressure levels.

Inventive Principle:
Principle #23Feedback

2Stress or pressure

If the fan operates at constant speed to provide maximum pressure, then the pressure requirement is met, but acoustic performance deteriorates

Engineering Contradiction:
Improvefan pressureVSAvoidacoustic noise
Core Design Contradiction:
Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The fan speed is made variable through an electronic control system that adjusts the motor speed based on actual ventilation requirements. The control unit receives feedback from pressure sensors and flow meters, dynamically adjusting the fan speed to match the required pressure level, thereby avoiding continuous operation at maximum speed and reducing energy consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements a closed-loop control with feedback from pressure sensors positioned in the ventilation network and flow meters. These sensors continuously monitor the actual pressure and flow conditions, sending signals to the electronic control unit which adjusts the fan speed accordingly, creating a self-regulating system that optimizes energy usage while maintaining required pressure levels.

Inventive Principle:
Principle #23Feedback

3Stress or pressure

If pressure sensors are placed at each terminal point of the network to regulate pressure, then pressure control is improved, but device complexity increases

Engineering Contradiction:
Improvepressure controlVSAvoidsystem complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The ventilation network is divided into multiple zones or sectors, each equipped with its own pressure sensor and control strategy. Instead of a single centralized control system managing the entire network, each segment operates semi-independently, allowing localized pressure regulation without requiring complex communication and coordination across the entire system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electronic control unit acts as an intermediary between the pressure sensors and the fan motor. It processes the pressure signals, applies control algorithms, and generates the appropriate motor speed commands, simplifying the overall system architecture by centralizing the control logic in a dedicated intermediate device rather than requiring direct complex interconnections between all components.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Productivity

If the installation is sized for maximum flow rate and maximum pressure, then the maximum operating point is achieved, but energy overconsumption occurs at partial flow rates

Engineering Contradiction:
Improvemaximum flow rateVSAvoidenergy overconsumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The fan speed is made variable through an electronic control system that adjusts the motor speed based on actual ventilation requirements. The control unit receives feedback from pressure sensors and flow meters, dynamically adjusting the fan speed to match the required pressure level, thereby avoiding continuous operation at maximum speed and reducing energy consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operating parameters of the fan by varying its speed rather than operating at a fixed maximum speed. The electronic control unit continuously adjusts the motor speed parameter based on feedback from pressure and flow sensors, allowing the fan to operate at optimal speed for each specific ventilation requirement, thus avoiding energy overconsumption when maximum flow is not needed.

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 results in energy savings and improved acoustic performance by ensuring the fan operates at the necessary pressure, adapting to varying ventilation conditions and reducing energy consumption.

Implementation Method 1

measure the air flow passing through the fan... by taking measurements of electrical information, such as current and voltage

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP1872061B1Method for controlling pressure delivered by the variable speed fan of a ventilation device
Publication Date: 2013.08.21 ALDES AERAULIQUE
  • EP1872061B1 patent drawingFigure 1~2
  • EP1872061B1 patent drawingFigure 3

AI summary

The inventive method consists in defining a device loss of load and in calculating a minimum required pressure corresponding to a minimum flow rate and a maximum required pressure corresponding to a maximum flow rate, in defining a flow rate/pressure curve between two predetermined points corresponding to the minimum pressure and flow rate and to the maximum pressure and flow rate, in measuring the air flow rate passing through a fan, in calculating the required pressure using the flow rate/pressure curve and in subsequently controlling the fan speed of rotation in such a way that said required pressure value is delivered.