Dishwasher Water Storage Heat Exchanger for Closed-Circuit Drying

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Solution Overview

Problem

The production of dishwashers equipped with both a liquid-storage system and a drying system is complex and costly, requiring a simpler and more efficient solution for reliable operation and increased efficiency.

Innovation Solution

A dishwashing machine design that incorporates a closed drying circuit and a water-storage system with a heat exchanger, utilizing a modular heat-exchange portion and a storage container to recover heat from used water, allowing for efficient reuse and reduced energy consumption, while minimizing the number of components and overall dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dishwashing machine is equipped with both a liquid-storage system and a drying system, then the quality of treatment and drying efficiency are improved, but the device complexity and production cost increase

Engineering Contradiction:
Improvequality of treatmentVSAvoidproduction complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the liquid-storage system and drying system into a single integrated structure. The storage container serves dual purposes: storing water for washing phases and acting as the drying circuit when empty. The container walls function both as storage boundaries and as heat exchange surfaces for drying, eliminating the need for separate drying components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The storage container is designed to perform multiple functions throughout the operating cycle: it stores water during washing phases, serves as a heat exchange medium for drying when water is discharged, and provides structural support. This multi-functionality reduces the overall number of components needed in the machine.

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

2Loss of energy

If a liquid-storage system with heat exchanger is added to recover heat from used water, then energy consumption is reduced, but the device complexity and dimensions increase

Engineering Contradiction:
Improveenergy consumptionVSAvoidnumber of components
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The heat exchanger is integrated directly into the walls of the storage container rather than being a separate component. The container walls themselves serve as the heat exchange surface, allowing thermal energy transfer between the stored water and the air in the drying chamber during the drying phase.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The storage container walls perform dual functions: containing the water during storage and serving as the heat exchange medium during drying. This eliminates the need for a separate heat exchanger component while maintaining effective heat recovery capability.

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

3Device complexity

If the storage container is used as a drying circuit by discharging water, then the drying system becomes simpler, but the programming time and cycle duration increase

Engineering Contradiction:
Improvedrying system complexityVSAvoidprogramming time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The drying process begins immediately after water discharge without requiring a separate initialization phase. The heat exchange between the container walls and drying air occurs continuously during the entire drying cycle, maximizing the utilization of thermal energy and reducing overall drying time.

Inventive Principle:
Principle #20Continuity of useful action

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 solution enables a simpler and cost-effective production of dishwashers with improved efficiency, reducing energy consumption and programming time, while maintaining effective dish drying and water treatment processes.

Implementation Method 1

a water-storage system with a heat exchanger, utilizing a modular heat-exchange portion and a storage container to recover heat from used water

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

Heating is obtained by way of one or more electrical resistances

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2687142B1Household dish-washing machine
Publication Date: 2015.03.18 INDESIT COMPANY SPA
  • EP2687142B1 patent drawingFigure 1~2
  • EP2687142B1 patent drawingFigure 3
  • EP2687142B1 patent drawingFigure 4~6

AI summary

A dish-washing machine comprises a base (2), a wash tub (3) supported by the base (2), and a control system (EC). The control system (EC) is prearranged for controlling execution of a plurality of dish-treatment programs, amongst which at least one first treatment program. Housed in the housing space (2a) is a storage container (30) having an inlet (31) and an outlet (32), and at least one portion (13a) of a first duct (13) for supplying the water into the wash tub extends within the storage container (30), to form a heat exchanger therewith. The machine has first means (22, 23, 26, 40; 22, 23, 26; 22, 26, 60), for supplying the storage container (30) with water, and second means (27, 28), for emptying from the storage container (30) water contained therein. The first treatment program includes a drying phase that can be carried out after emptying-out of the water from the storage container (30) and the storage container (30) has at least one air inlet (36), in fluid communication with the delivery branch of a fan (50), and at least one air outlet (37), in fluid communication with the inside of the tub (3). The control system (EC) is configured for controlling the fan (50) in the course of the drying phase, for bringing about passage of a flow of air in the storage container (30), between the air inlet (36) and the air outlet (37), in such a way that the flow of air laps said portion (13) of the first supply duct (13).