Motor-Driven Heating for Water-Circulating Household Appliances

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing water-circulating household appliances, such as dishwashers and washing machines, require additional heating elements to provide warm washing liquid, which increases costs and energy consumption.

Innovation Solution

The method involves driving the electric motor with higher electrical power input than necessary for circulating the washing liquid, causing excess energy to be converted into heat in the motor windings, which is then transferred to the washing liquid through thermal communication, thereby eliminating the need for a separate heating element and reducing water volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a separate heating element is added to the water-circulating household appliance, then the washing liquid can be heated effectively, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvewashing liquid temperatureVSAvoidheating system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the heating function with the existing electric motor by creating thermal communication between the motor housing and the washing liquid circuit. The motor housing serves dual purposes: driving the pump and heating the washing liquid through controlled inefficient operation, eliminating the need for a separate heating element.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The electric motor is designed to perform multiple functions: it drives the pump for water circulation and simultaneously serves as a heating device for the washing liquid. This multi-functionality reduces the overall number of components needed in the system.

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

2Temperature

If a separate heating element and heating compartment are added, then the washing liquid can be heated, but the total water volume in the appliance increases

Engineering Contradiction:
Improvewashing liquid temperatureVSAvoidtotal water volume
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The heating function is integrated into the existing motor housing space rather than adding a separate heating compartment. The washing liquid circuit is thermally coupled to the motor housing, allowing heating without requiring additional dedicated space or water volume for a separate heating system.

Inventive Principle:
Principle #5Merging (Combining)

3Temperature

If the electric motor is driven with higher electrical power input causing low efficiency, then excess heat is generated for heating the washing liquid, but energy consumption increases

Engineering Contradiction:
Improvewashing liquid temperatureVSAvoidelectrical energy consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful waste heat generated by inefficient motor operation into a useful heating function for the washing liquid. By intentionally operating the motor at lower efficiency, the excess electrical energy that would normally be wasted is transformed into thermal energy that heats the washing liquid, eliminating the need for separate heating elements.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 reduces the cost and energy consumption of the appliance by utilizing motor heat to warm the washing liquid, allowing for a more efficient and cost-effective operation without a dedicated heating compartment.

Implementation Method 1

excess electric energy input to the electric motor is transformed to heat in the windings of the electric motor

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the heat is transferred to the washing liquid in this portion of the washing liquid circuit

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2878250B1Method of operating a water-circulating household appliance
Publication Date: 2020.02.26 ELECTROLUX APPLIANCES
  • EP2878250B1 patent drawingFigure 1
  • EP2878250B1 patent drawingFigure 2

AI summary

Herein a method of operating a water-circulating household appliance 2 is disclosed. The water-circulating household appliance 2 comprises an electric motor 4 and a washing liquid circuit 6, the washing liquid circuit comprising a pump 8 for circulating washing liquid through the washing liquid circuit. A portion of the washing liquid circuit is arranged in thermal communication with the electric motor. For heating the washing liquid, the method comprises a step of driving the electric motor, over a time period longer than 1 minute, with a higher electrical power input than required for circulating the washing liquid through the washing liquid circuit with the pump rotating in the primary direction of rotation. Also disclosed is a water-circulating household appliance 2.