Method for determining core temperature of cooked food and cooking device to perform this method

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Solution Overview

Problem

Existing methods for determining the core temperature of food during cooking are prone to errors due to incorrect placement of temperature sensors, leading to inaccurate cooking process control and documentation issues, especially when the sensor does not hit the core of the food.

Innovation Solution

A method that specifies boundary conditions for the heat conduction equation using input from a cooking appliance or additional sensors, including the size, shape, and thermal properties of the food, to accurately estimate the core temperature, even if the sensor is poorly placed, by employing dimensionless variables and approximate solutions to the heat conduction equation for different food geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a temperature sensor is inserted into food to measure core temperature, then cooking process control is enabled, but measurement accuracy deteriorates when the sensor is incorrectly placed and does not hit the core

Engineering Contradiction:
Improvecooking process controlVSAvoidcore temperature measurement
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent transforms the temperature measurement problem from directly reading sensor values to calculating core temperature through mathematical parameters. By solving the heat conduction equation with boundary conditions (food geometry, thermal properties, surface temperature, initial temperature), the system calculates the actual core temperature even when sensors are misplaced, converting an inaccurate direct measurement into an accurate calculated value through parameter transformation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces mathematical models and heat conduction equations as intermediaries between the temperature sensors and the core temperature determination. Instead of directly using sensor readings, the system uses these intermediate calculations to infer the true core temperature, effectively mediating the measurement process to overcome placement errors

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If multiple temperature sensors are used to improve measurement reliability, then the probability of hitting the core increases, but device complexity and cost increase

Engineering Contradiction:
Improvecore temperature measurementVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the core temperature calculation from the physical sensor placement requirement. By removing the necessity for precise sensor positioning and using mathematical extraction of the core temperature value from the heat conduction model, the system achieves accurate measurement with simpler, fewer sensors, eliminating the need for complex multi-sensor arrays

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If direct temperature reading from sensor is used, then measurement is simple and fast, but accuracy is lost when sensor is not at the core

Engineering Contradiction:
Improvetemperature measurementVSAvoidcore temperature accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent performs preliminary calculations by solving the heat conduction equation and determining the relationship between sensor positions and core temperature before final measurement interpretation. By pre-establishing the mathematical model with boundary conditions and solving for the temperature distribution, the system prepares the calculation framework in advance, allowing accurate core temperature determination from simple sensor readings without requiring complex real-time measurements

Inventive Principle:
Principle #10Preliminary 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 a more precise estimation of the core temperature, improving cooking process control and hygiene documentation by accounting for various food shapes and properties, ensuring accurate core temperature determination regardless of sensor placement.

Implementation Method 1

at least one temperature sensor which can be placed in a cooking space and which is suitable for determining a temperature at least at one point inside the food to be cooked

Methodology Applied
Scientific EffectThermal energy detection: Thermocouple

Implementation Method 2

whereby a core temperature of the food to be cooked is calculated from the measured temperature values taken inside the food... by solving a heat conduction equation

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP2026632B1Method for determining core temperature of cooked food and cooking device to perform this method
Publication Date: 2017.01.25 RATIONAL AG
  • EP2026632B1 patent drawingFigure 1
  • EP2026632B1 patent drawingFigure 2
  • EP2026632B1 patent drawingFigure 3

AI summary

The method involves partially introducing a temperature sensor (6) into a cooked food (1), which is occasionally heated from outside portion during a cooking process. Temperature of the cooked food is measured twice or in continuous manner by using the sensor. Two boundary conditions for solving a heat conduction equation are provided in an input device, and a reading device of the cooking device. The boundary conditions are determined by evaluating measurement data of another sensor during the cooking process, and are defined by empirical values obtained prior to the cooking process. An independent claim is also included for a cooking device for handling a cooked food in a cooking chamber.