Cooking device with a component that heats up during operation and method for cooling such a component

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Solution Overview

Problem

Cooking appliances experience prolonged operation of cooling air fans after components have switched off, leading to noise disturbance and inefficient energy use during the cooling air fan run-on time.

Innovation Solution

Incorporating a heat pipe as a secondary cooling unit that takes over from the cooling air fan to cool components after they have switched off, allowing for silent and energy-efficient operation by reducing the need for continuous fan operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the cooling air fan continues to operate after the component has been switched off to cool the heated component, then the component can be cooled effectively, but noise is generated and energy is consumed unnecessarily

Engineering Contradiction:
Improvecomponent temperatureVSAvoidnoise
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical cooling air fan with a heat pipe-based passive cooling system. The heat pipe utilizes phase change (evaporation and condensation) of a working fluid to transfer heat from the component without requiring mechanical movement, thereby eliminating noise generation while maintaining effective cooling capability during the fan run-on time.

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

Solution Approach 2:

The heat pipe system operates autonomously without requiring external power or control mechanisms. The phase change process occurs naturally based on temperature differential, allowing the component to cool itself during the fan run-on time without active intervention, thus avoiding noise and energy consumption associated with continued fan operation.

Inventive Principle:
Principle #25Self-service

2Temperature

If the cooling air fan continues to operate after the component has been switched off to cool the heated component, then the component can be cooled effectively, but energy is consumed during the cooling air fan run-on time

Engineering Contradiction:
Improvecomponent temperatureVSAvoidfan energy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent substitutes the energy-consuming mechanical fan with a passive heat pipe system that utilizes natural phase change processes. This eliminates the need for electrical energy input during the cooling period, as the heat pipe automatically transfers thermal energy from the hot component to the surrounding environment through evaporation and condensation cycles.

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

Solution Approach 2:

The heat pipe system performs cooling autonomously without requiring external energy supply. The phase change mechanism self-regulates based on temperature conditions, enabling the component to cool itself during the fan run-on time without additional energy consumption, thus resolving the contradiction between effective cooling and energy efficiency.

Inventive Principle:
Principle #25Self-service

3Object-generated harmful factors

If a heat pipe is used to cool the component during cooling air fan run-on time, then noise is reduced and energy consumption is reduced, but the device complexity increases

Engineering Contradiction:
ImprovenoiseVSAvoidcooling system complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent utilizes the existing heat pipe structure that is already present in the device for its primary cooling function during operation. By recovering and extending the use of this existing thermal management component during the fan run-on time, the system achieves additional cooling capability without requiring completely new components, thereby minimizing the increase in device complexity.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The heat pipe is designed to serve multiple functions: active cooling during component operation and passive cooling during the fan run-on time. This multi-functionality allows a single component to address different cooling requirements at different operational stages, reducing the need for separate cooling systems and thereby limiting the increase in overall device complexity.

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

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

The heat pipe enables rapid and effective cooling of components post-operation, significantly reducing noise and energy consumption during the cooling air fan run-on time, allowing for more user-friendly and energy-efficient operation.

Implementation Method 1

A cooking appliance with a cooling unit is known from EP 1 601 236 A2. The cooking appliance designed specifically as a hob includes at least one heat pipe, which belongs to the cooling unit and is designed for cooling.

Methodology Applied
Scientific EffectHeat pipe: Heat Pipe

Implementation Method 2

A heat pipe within the meaning of the application is a heat exchanger that allows a high heat flow density using the heat of vaporization of a substance, ie large amounts of heat can be transported on a small cross-sectional area.

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

The device has a fan for generating a flow of cooling air.

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP2306092B1Cooking device with a component that heats up during operation and method for cooling such a component
Publication Date: 2020.04.22 BSH HAUSGERATE GMBH
  • EP2306092B1 patent drawingFigure 1

AI summary

The cooking device i.e. microwave oven (1), has a cooling air blower (13) for cooling a circuit carrier (11) and a power semiconductor component (12) that are heated during operation of the cooking device. The circuit carrier and the semiconductor component are temporarily cooled by a heat pipe (14) in after-run-time of the cooling air blower in an operating mode. The heat pipe is connected with a control unit (15). The heat pipe is arranged electrically isolated from the circuit carrier and the semiconductor component. An independent claim is also included for a method for cooling a circuit carrier and a power semiconductor component of a cooking device.