Dishwasher Intermittent Drying Control to Reduce Energy Consumption

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Solution Overview

Problem

Conventional dishwashers face inefficiencies in drying processes, with the circulation type method having lower drying efficiency and the exhaustion type method consuming high energy, especially when dealing with large loads of dishes.

Innovation Solution

A dishwasher with a controlling method that includes a dry maintaining step, where the drying module operates intermittently for a preset time period, using night-time electricity to maintain a dried state of dishes, even after the primary drying process is completed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the circulation type drying method is used, then the drying process can be performed within the washing tub, but the drying efficiency is lower compared to exhaustion type method

Engineering Contradiction:
Improvedrying efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by stationary object

Solution Approach 1:

The drying module operates intermittently rather than continuously, with periodic activation of the heating unit and circulation fan. This periodic operation reduces energy consumption while maintaining effective drying through accumulated thermal effects during operation cycles.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system changes operational parameters by adjusting heating power and fan speed based on drying progress and energy efficiency requirements. The heating unit operates at optimized power levels during intermittent cycles to achieve effective drying with reduced energy input compared to continuous operation.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the exhaustion type drying method is used, then higher drying efficiency is achieved, but energy consumption increases significantly

Engineering Contradiction:
Improvedrying efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by stationary object

Solution Approach 1:

The exhaust fan and heating unit operate in periodic cycles rather than continuously. The system activates heating and exhaust functions intermittently, allowing thermal energy to accumulate and maintain drying effectiveness while reducing overall energy consumption compared to continuous exhaustion type operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The drying system utilizes the thermal energy already present in the washing tub after washing cycles, and the natural heat retention properties of the enclosed space. This self-sustaining thermal environment reduces the need for continuous high-energy exhaust operation.

Inventive Principle:
Principle #25Self-service

3Reliability

If the drying module operates continuously to maintain dried state, then dishes remain dry longer, but energy consumption increases

Engineering Contradiction:
Improvedried state maintenanceVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The drying module switches from continuous operation to periodic intermittent operation after the main drying cycle. The heating unit and circulation fan activate at scheduled intervals to refresh the dried state, maintaining dish dryness while dramatically reducing energy consumption compared to continuous operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The control unit monitors drying progress and environmental conditions to determine optimal intervals for intermittent drying module operation. This feedback-based timing ensures dishes remain dry by activating the drying function only when necessary, rather than continuous operation.

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

The method effectively maintains a dried condition for dishes, allows for energy-efficient drying using cheap night-time electricity, and can perform drying processes during late nights when the dishwasher is not in use, reducing overall energy consumption.

Implementation Method 1

a drying module drying the dishes placed in the washing tub... a heating unit heating air in the drying module

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a circulation fan circulating the air heated by the heating unit in the drying module

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

an exhaust fan exhausting the air inside the washing tub to the outside

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 4

water is condensed and removed by the circulation duct

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3189764B1Dishwasher and controlling method thereof
Publication Date: 2019.10.23 LG ELECTRONICS INC
  • EP3189764B1 patent drawingFigure 1
  • EP3189764B1 patent drawingFigure 2
  • EP3189764B1 patent drawingFigure 3

AI summary

A controlling method of a dishwasher comprising: a water supply step for supplying wash water to the dishwasher;a washing step for washing one or more dishes by using the wash water;a rinsing step for rinsing the washed dishes; a drying step for drying the rinsed dishes, and a dry maintaining step for intermittently drying the dishes to maintain a dried state of the dishes.