Dynamic Heating Power Control for Aerosol Generation

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Solution Overview

Problem

Existing electrically heated aerosol generating systems lack efficient control over heating elements, leading to overheating or underheating issues, which affect aerosol properties and can result in liquid leakage.

Innovation Solution

A method and system that utilize a sensor to detect airflow indicative of a user's puff, adjusting heating power from zero to a defined level (p1) when airflow increases to a first threshold and decreasing it to zero when airflow decreases to a second threshold, with the first threshold being smaller than the second, to optimize energy usage and aerosol formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the heating element is activated continuously during the puff, then the aerosol formation is maintained, but the heating element overheats and causes liquid leakage

Engineering Contradiction:
Improveaerosol formation consistencyVSAvoidheating element temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The heating power is dynamically adjusted during the puff based on real-time airflow detection. The system transitions from static continuous heating to dynamic variable heating, reducing power when airflow decreases to prevent overheating while maintaining adequate heating for aerosol formation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses airflow sensors to continuously monitor the puff characteristics and feeds this information back to the control circuitry, which adjusts the heating power accordingly. This closed-loop feedback mechanism prevents overheating by reducing power when airflow decreases, while ensuring adequate heating when airflow is sufficient.

Inventive Principle:
Principle #23Feedback

2Quantity of substance

If the heating power is increased to ensure adequate aerosol formation, then the aerosol concentration is improved, but energy consumption increases

Engineering Contradiction:
Improveaerosol concentrationVSAvoidenergy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The system changes the heating power parameter dynamically during the puff based on airflow detection. Power is increased when airflow is high to ensure adequate aerosol formation, and reduced when airflow decreases to minimize energy consumption. This parameter adjustment optimizes the balance between aerosol concentration and energy usage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies partial heating power rather than maximum continuous power. By adjusting power levels to match actual puff requirements, the system avoids excessive energy consumption while maintaining sufficient heating for adequate aerosol formation throughout the puff duration.

Inventive Principle:
Principle #16Partial or excessive action

3Use of energy by moving object

If the heating power is decreased to reduce energy usage, then energy efficiency is improved, but the heating element becomes too cool and affects condensation formation

Engineering Contradiction:
Improveenergy efficiencyVSAvoidheating element temperature
Core Design Contradiction:
Use of energy by moving objectVSTemperature

Solution Approach 1:

The heating power is dynamically adjusted during the puff based on real-time airflow detection. The system transitions from static continuous heating to dynamic variable heating, reducing power when airflow decreases to prevent overheating while maintaining adequate heating for aerosol formation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses airflow sensors to continuously monitor the puff characteristics and feeds this information back to the control circuitry, which adjusts the heating power accordingly. This closed-loop feedback mechanism prevents overheating by reducing power when airflow decreases, while ensuring adequate heating when airflow is sufficient.

Inventive Principle:
Principle #23Feedback

4Object-affected harmful factors

If the heating element is turned off early to prevent overheating, then liquid leakage is prevented, but the aerosol formation is incomplete

Engineering Contradiction:
Improveliquid leakageVSAvoidaerosol formation completeness
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The heating power is dynamically adjusted during the puff based on real-time airflow detection. The system transitions from static continuous heating to dynamic variable heating, reducing power when airflow decreases to prevent overheating while maintaining adequate heating for aerosol formation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses airflow sensors to continuously monitor the puff characteristics and feeds this information back to the control circuitry, which adjusts the heating power accordingly. This closed-loop feedback mechanism prevents overheating by reducing power when airflow decreases, while ensuring adequate heating when airflow is sufficient.

Inventive Principle:
Principle #23Feedback

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 tailors the heating profile to the puff profile, optimizing aerosol properties, reducing overheating, and minimizing liquid leakage by ensuring appropriate condensation formation and energy efficiency.

Implementation Method 1

a sensor for detecting airflow indicative of a user taking a puff having an airflow duration

Methodology Applied
Scientific EffectAirflow detection:

Implementation Method 2

at least one electric heating element for heating an aerosol-forming substrate to form the aerosol

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

heating an aerosol-forming substrate to form the aerosol

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

The decrease of power towards the end of the puff affects the cooling of the heating element and hence the temperature of the heating element and its vicinity. This, in turn, affects how much condensation is able to form in the system

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP2645892B1An electrically heated aerosol generating system having improved heater control
Publication Date: 2019.03.27 PHILIP MORRIS PRODUCTS SA
  • EP2645892B1 patent drawingFigure 1
  • EP2645892B1 patent drawingFigure 2~4
  • EP2645892B1 patent drawingFigure 5~6

AI summary

There is provided a method for controlling at least one electric heating element of an electrically heated aerosol generating system for heating an aerosol-forming substrate. The electrically heated aerosol generating system has a sensor for detecting airflow indicative of a user taking a puff having an airflow duration. The method comprises the steps of: increasing the heating power for the at least one heating element from zero to power p1 when the sensor detects that the airflow rate has increased to a first threshold, maintaining the heating power at a power p1 for at least some of the airflow duration, and decreasing the heating power for the at least one heating element from power p1 to zero when the sensor detects that the airflow rate has decreased to a second threshold.