Microwave Power Control via Core Temperature Feedback

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Solution Overview

Problem

Existing microwave cooking technologies fail to achieve the fastest possible cooking while minimizing energy consumption, as they primarily focus on maintaining temperature distribution and preventing surface drying without optimizing microwave power settings based on food characteristics and cooking process parameters.

Innovation Solution

The method involves determining the target difference quotient, gradient, or C-value as a function of food and cooking process parameters, using temperature sensors to adjust microwave power, and combining microwave radiation with steam and hot air to optimize core temperature rise, thereby minimizing energy usage and cooking time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If microwave power is increased to reduce cooking time, then cooking speed improves, but energy consumption increases and temperature distribution becomes uneven

Engineering Contradiction:
Improvecooking speedVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The microwave power is dynamically adjusted during the cooking process based on real-time core temperature measurements. The control device continuously monitors the core temperature and modifies the microwave power output accordingly, transitioning from high power at the beginning to lower power as the core temperature approaches the target value, thereby optimizing both cooking speed and energy consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A feedback control system is implemented where the core temperature sensor provides continuous temperature data to the control device. The control device processes this feedback information and adjusts the microwave power in response, creating a closed-loop control system that automatically optimizes cooking parameters based on actual cooking progress

Inventive Principle:
Principle #23Feedback

2Productivity

If microwave power is increased to reduce cooking time, then cooking speed improves, but temperature distribution uniformity deteriorates

Engineering Contradiction:
Improvecooking speedVSAvoidtemperature distribution uniformity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The microwave power is dynamically adjusted during the cooking process based on real-time core temperature measurements. The control device continuously monitors the core temperature and modifies the microwave power output accordingly, transitioning from high power at the beginning to lower power as the core temperature approaches the target value, thereby optimizing both cooking speed and energy consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A feedback control system is implemented where the core temperature sensor provides continuous temperature data to the control device. The control device processes this feedback information and adjusts the microwave power in response, creating a closed-loop control system that automatically optimizes cooking parameters based on actual cooking progress

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If microwave power is optimized based on core temperature rise saturation, then energy consumption decreases, but cooking time may increase

Engineering Contradiction:
Improveenergy consumptionVSAvoidcooking time
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The system performs preliminary high-power microwave heating to rapidly raise the core temperature during the initial phase of cooking. This preliminary action allows the food to quickly approach the target temperature range, after which the power is reduced to avoid excessive energy consumption, thereby achieving an optimal balance between cooking time and energy usage

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The microwave heating is conducted in periodic phases with different power levels. The process includes an initial high-power phase for rapid heating, followed by a lower-power phase for temperature maintenance and completion of cooking. This periodic action pattern optimizes energy efficiency while maintaining acceptable cooking time

Inventive Principle:
Principle #19Periodic action

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 allows for the fastest possible cooking with minimal energy consumption by setting optimal microwave power based on core temperature rise, which saturates at a certain level, ensuring efficient heat diffusion and preventing unnecessary energy expenditure.

Implementation Method 1

the direct absorption of microwave radiation in the food to be cooked

Methodology Applied
Scientific EffectMicrowave radiation absorption: Absorption (EM radiation)

Implementation Method 2

provision of powerful microwave sources

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 3

detect the surface temperature and the core temperature of an item to be cooked using an arrangement of temperature sensors

Methodology Applied
Scientific EffectThermal energy detection: Thermocouple

Implementation Method 4

ensuring efficient heat diffusion

Methodology Applied
Scientific EffectHeat diffusion: Diffusion

Data Source

PatentEP2136604B1Method for adjusting microwave output in a microwave cooking device depending on the measured core temperature and cooking device
Publication Date: 2011.04.20 TOPINOX
  • EP2136604B1 patent drawingFigure 1
  • EP2136604B1 patent drawingFigure 2
  • EP2136604B1 patent drawingFigure 3

AI summary

The method involves measuring core temperature at two time points, and determining difference coefficients of core temperature from change of the measured temperature in a time interval. Increase of the core temperature is determined from deviation of the measured temperature, and a C-value is determined from characteristics of the measured temperature. The determined coefficients, temperature increase and C-value are compared with target difference coefficients, target temperature increase, and target C-value, respectively. Microwave power is adjusted based on the comparison results. An independent claim is also included for a cooking device comprising a heating device.