Method for controlling an oven and oven

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Solution Overview

Problem

Existing oven control methods are inefficient in energy-saving modes and require significant changes to the oven's structure, which complicates their implementation.

Innovation Solution

A method that uses an electromechanical temperature control with a mechanical temperature sensor and a switching contact, where the muffle heating is operated at full power during a preheating phase and then controlled using a power control phase with a defined ratio of on-time to off-time to maintain a temperature slightly below the setpoint, reducing energy consumption without precise temperature detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the muffle heating is operated at full power to maintain the set temperature, then the temperature control precision is improved, but the energy consumption increases

Engineering Contradiction:

Improvetemperature control precisionVSAvoidenergy consumption

Core Design Contradiction:

TemperatureVSUse of energy by moving object

Solution Approach 1:

The heating device operates in periodic cycles with defined on-time and off-time periods instead of continuous full power operation. The control method switches between full power heating and reduced power states in a clocked manner, achieving energy savings while maintaining acceptable temperature control through periodic heating action.

Inventive Principle:

Principle #19Periodic action

2Loss of energy

If the oven construction is significantly changed to implement energy-saving control, then the energy-saving capability is improved, but the device complexity increases

Engineering Contradiction:

Improveenergy-saving capabilityVSAvoidconstruction complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The existing electromechanical temperature control system is utilized to determine when to switch heating states, making the system self-regulating without requiring additional complex control components. The control method leverages the already-present temperature sensor and switching contact to trigger power control phases, avoiding the need for separate control systems.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The existing temperature control components serve dual purposes: traditional temperature regulation and triggering energy-saving power control phases. The electromechanical temperature control not only maintains temperature but also initiates the power control phase when the set temperature is reached, eliminating the need for dedicated energy-saving control hardware.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Use of energy by moving object

If the temperature is reduced by 10K to 40K below the setpoint during power control phase, then the energy consumption is reduced, but the cooking time increases

Engineering Contradiction:

Improveenergy consumptionVSAvoidcooking time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The control method changes the temperature parameter dynamically by switching between full power heating (reaching set temperature) and reduced power phases (allowing temperature to drop 10K-40K below setpoint). This parameter variation enables energy savings during power control phases while accepting extended cooking time to complete the thermal process.

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 allows for energy-saving operation without altering the oven's construction, maintaining cooking quality while significantly reducing energy usage by operating at a temperature 10K to 40K below the setpoint, thus extending cooking time and conserving energy.

Implementation Method 1

a mechanical temperature sensor and a switching contact... The mechanical temperature sensor often consists of a pipe system that is filled with an oil that expands depending on the temperature

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a muffle heater... activating a heater element to heat the cooking cavity

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3267114B1Method for controlling an oven and oven

Publication Date: 2019.12.25 E G O ELEKTRO GERAETEBAU GMBH

Figure 1~3
Figure 4

AI summary

In an energy-saving mode, an oven (1) can switch from operation with temperature control to operation with power specification during a cooking process. For this purpose, a microcontroller (16) and a relay (17) are provided as an additional switch on an additional circuit board (15) for retrofitting. In a power control phase, constant power is supplied to a muffle heater (3) by constant clocking. The level of this is determined by observing and evaluating a preheating phase and a short temperature holding phase, from which a constant ratio of the duty cycle to the cycle period (ED) of the muffle heater (3) is determined. In this way, energy can be saved by lowering the temperature in the oven muffle (2) below a predetermined target temperature.