Induction-Heated Washer Drum Control With Low-Water Circulation

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Solution Overview

Problem

Conventional washing machines consume a large volume of water to maintain a heater protection level, limiting the use of high-concentration detergent water and increasing washing time, while also restricting the flexibility in selecting the net acting ratios of the motor and circulation pump during the heating step.

Innovation Solution

A method of controlling a washing apparatus that allows for increased laundry soaking efficiency by driving a circulation pump during soaking with a small amount of water, reducing soaking time, and enhancing washing performance by increasing the net acting ratios of the drum and circulation pump during the heating step, while abandoning the heater protection water level, using an induction module to directly heat the drum and indirectly heat the washing water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a heater protection water level is maintained to protect the heater, then the heater can be completely immersed and protected, but the water consumption increases significantly (about 6 liters required just for heater protection)

Engineering Contradiction:
Improveheater protectionVSAvoidwater consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent introduces a circulation pump as an intermediary device that pumps washing water from the tub and sprays it onto the heater. This allows the heater to be protected from overheating and damage even when the water level is below the heater protection level, as the circulating water continuously contacts and cools the heater surface. This resolves the contradiction by enabling heater protection without requiring large volumes of water to maintain a high water level.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If washing water is sufficiently supplied for laundry soaking (200% water-to-laundry ratio), then good soaking is achieved, but the total water consumption increases (about 12 liters for 3 kg laundry)

Engineering Contradiction:
Improvelaundry soaking qualityVSAvoidwater consumption
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The circulation pump operates continuously during the washing cycle, constantly pumping water from the tub and spraying it onto the heater and surrounding areas. This continuous circulation ensures that washing water is repeatedly distributed throughout the washing chamber, improving its penetration into the laundry and enhancing soaking quality without requiring a proportional increase in total water volume. The same water is reused multiple times through continuous circulation.

Inventive Principle:
Principle #20Continuity of useful action

3Productivity

If the circulation pump is used to circulate washing water, then washing water can be sprayed onto laundry to enhance washing effect, but more washing water is required to fill the circulation channel

Engineering Contradiction:
Improvewashing effectVSAvoidwater consumption
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent employs a circulation pump that dynamically circulates washing water through a controlled system, pumping water from the tub and directing it through spray nozzles onto the heater and laundry. This dynamic circulation system allows the same volume of water to be reused repeatedly throughout the washing cycle, maintaining effective washing action without requiring a large static volume of water to fill extensive circulation channels. The water is continuously moved and redistributed, maximizing its utility.

Inventive Principle:
Principle #15Dynamics

4Productivity

If the net acting ratios of motor and circulation pump are increased during heating step, then washing performance is enhanced, but the flexibility in selecting operating parameters is restricted

Engineering Contradiction:
Improvewashing performanceVSAvoidparameter selection flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent incorporates temperature sensing during the heating step to monitor the temperature of washing water and heater. This feedback mechanism allows the control system to adjust the net acting ratios of the motor and circulation pump based on actual temperature conditions, optimizing washing performance while preventing overheating. The system can dynamically modify operating parameters within safe limits, maintaining both high productivity and adaptability through real-time monitoring and adjustment.

Inventive Principle:
Principle #23Feedback

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 water consumption, enables washing with high-concentration detergent, shortens washing time, and improves energy efficiency by allowing the induction module to operate for a longer period, ensuring safe heating and preventing overheating through temperature sensing, thus enhancing overall washing performance.

Implementation Method 1

an induction module mounted on a surface of the tub and configured to heat the drum through electromagnetic induction

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3757269B1Washing apparatus and method for controlling same
Publication Date: 2024.07.31 LG ELECTRONICS INC
  • EP3757269B1 patent drawingFigure 1~2
  • EP3757269B1 patent drawingFigure 3
  • EP3757269B1 patent drawingFigure 4

AI summary

Provided is a washing apparatus equipped with an induction heater to heat a drum and a method of controlling the washing apparatus. The method includes a water supply step of supplying washing water to the tub via a water valve, a soaking step of soaking laundry by driving the drum while circulating washing water with the circulation pump after the water supply step ends, a heating step of heating the drum by driving the induction module after the soaking step ends, and a main washing step of washing the laundry by driving the drum after the heating step ends, wherein in the heating step, a water level is below a lower end of the drum, and the drum, the circulation pump, and the induction module are driven to operate, thereby heating the drum, the washing water, and the laundry.