Fan Volume Flow Detection Using Microcontroller Simulation

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Solution Overview

Problem

Existing volume flow control methods for fans require costly sensors and measuring devices, which increase installation effort and disrupt airflow due to flow resistance and turbulence.

Innovation Solution

A volume flow detection device using a microcontroller and simulation model to determine fan volume flow based on motor speed, incorporating a correction factor for pressure losses to align simulation results with measurements, allowing for iterative adjustments to achieve accurate volume flow control without additional sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sensor and volume flow measuring device are installed in the flow channel to measure volume flow, then the volume flow can be determined accurately, but the installation effort increases and the airflow is disrupted due to flow resistance and turbulence

Engineering Contradiction:
Improvevolume flow measurement accuracyVSAvoidinstallation effort and system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the measurement function from physical sensors in the flow channel and relocates it to a simulation model running on a microcontroller. The volume flow is calculated virtually using the relationship between motor speed and volume flow, eliminating the need for physical measuring devices in the airflow path.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a virtual copy of the fan system's performance characteristics through a simulation model stored in memory. This model replicates the relationship between motor speed and volume flow, allowing accurate measurement without physical sensors. The simulation model acts as a digital twin that predicts volume flow based on motor speed input.

Inventive Principle:
Principle #26Copying

2Measurement precision

If a sensor and volume flow measuring device are installed in the flow channel to measure volume flow, then the volume flow can be determined accurately, but additional costs for the measuring device and sensor are incurred

Engineering Contradiction:
Improvevolume flow measurement accuracyVSAvoidcost-effectiveness
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, complex measuring devices with a cost-effective microcontroller and simulation model. The solution uses inexpensive computational resources to perform calculations that would otherwise require costly hardware, making the system economically viable while maintaining measurement accuracy.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent substitutes mechanical and optical measuring systems with an electronic computational system. Instead of using physical sensors, flow channels, and measuring devices, the solution uses a microcontroller to calculate volume flow from motor speed data, replacing complex hardware with software-based computation.

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

3Ease of operation

If the speed of the blower motor is adjusted via a frequency converter to regulate volume flow, then the volume flow can be controlled, but the system complexity increases

Engineering Contradiction:
Improvevolume flow control capabilityVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements a feedback control system where the microcontroller continuously monitors motor speed, calculates the resulting volume flow using the simulation model, compares it with the target volume flow, and adjusts the motor speed accordingly. This closed-loop control enables precise volume flow regulation without requiring complex external control systems.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The microcontroller serves multiple functions: it reads motor speed, executes the simulation model to calculate volume flow, performs control calculations, and outputs control signals to the motor. This multi-functional approach consolidates what would otherwise require separate components into a single integrated control unit, reducing system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3887683B1Determination of volume flow rate
Publication Date: 2024.02.07 EBM PAPST MULFINGEN GMBH & CO KG
  • EP3887683B1 patent drawingFigure 1
  • EP3887683B1 patent drawingFigure 2
  • EP3887683B1 patent drawingFigure 3

AI summary

The invention relates to a volume flow rate detection device of a fan comprising a motor (M) having a speed controller (D) and at least one microcontroller (10), wherein the speed n of the motor (M) is input at an input of the microcontroller as an input variable in the form of a digital signal, in order to determine the pressure difference Δρ generated by the impeller wheel at this speed and the volume flow rate ΔV/Δt at a location x in a flow channel of the fan in a specific installation situation of a system (A), by means of a simulation model (SM) stored in a memory of the microcontroller (10), and in order to adjust the speed n of the motor accordingly by means of the speed controller in the event of a deviation from a setpoint volume flow rate ΔVSoll/Δt.