Heat Pump Dishwasher Drying Pocket Using Reused Condensate

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Solution Overview

Problem

In dishwashers using heat pumps for water heating, condensate water collected under the heat exchanger can cause bad odors and electrical failures if not discharged properly, and existing solutions do not efficiently utilize this water for enhanced drying efficiency.

Innovation Solution

A dishwasher design featuring a water duct connecting the drip tray to a drying pocket on the tub, with a pump and control unit to efficiently discharge condensate water, which is then used to cool the drying pocket, enhancing condensation and reducing energy consumption in the drying process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If condensate water is collected in the drip tray under the heat exchanger, then the heat pump can effectively draw heat from the environment, but the collected water causes bad odors and electrical failures when not discharged

Engineering Contradiction:
Improveheat pump effectivenessVSAvoidbad odors and electrical failures
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful condensate water into a useful cooling resource. The collected condensate is pumped to the drying pocket where it circulates through channels to cool the pocket walls, enhancing condensation of humid air during the drying phase. This transforms the harmful standing water into a beneficial cooling medium that improves drying efficiency while preventing odors and electrical failures.

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

Solution Approach 2:

The system uses the condensate water from the heat pump operation itself to provide cooling for the drying pocket, creating a self-sufficient system. The water that would otherwise be waste is reused within the same system to support the drying function, eliminating the need for separate cooling mechanisms and reducing overall energy consumption.

Inventive Principle:
Principle #25Self-service

2Reliability

If a drip tray is used to collect condensate under the heat exchanger, then moisture condensation is captured, but the tray requires additional discharge mechanisms and space

Engineering Contradiction:
Improvecondensate collectionVSAvoiddischarge mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The condensate collected in the drip tray serves multiple functions: it is first collected for reliable condensate management, then pumped to the drying pocket for cooling purposes, and finally discharged through the drying pocket after providing its cooling function. This multi-functional use of the same water resource eliminates the need for separate discharge mechanisms and reduces system complexity.

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

Solution Approach 2:

The patent merges the condensate collection function with the drying pocket cooling function. The drip tray and drying pocket discharge system are combined into a single integrated pathway, where the condensate discharge route is shared with the cooling water circulation route, reducing the number of separate components and simplifying the overall system.

Inventive Principle:
Principle #5Merging (Combining)

3Device complexity

If traditional drying methods are used without utilizing condensate water, then the drying process is simpler, but energy consumption is higher

Engineering Contradiction:
Improvedrying process simplicityVSAvoiddrying energy consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary cooling of the drying pocket walls by circulating condensate water through channels before the drying phase begins. This pre-cooling action prepares the drying pocket to efficiently condense humid air from the beginning of the drying cycle, eliminating the need for complex active cooling systems during drying and reducing overall energy consumption while maintaining operational simplicity.

Inventive Principle:
Principle #10Preliminary 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 efficient discharge and reuse of condensate water improve drying efficiency by providing a cold surface for condensation, preventing moisture buildup and reducing energy consumption without causing electrical failures or bad odors.

Implementation Method 1

The heat pumps are operated with the principle that the refrigerant is compressed and expanded between at least two heat exchangers, thus providing heat transfer

Methodology Applied
Scientific EffectHeat pump principle: Heat Exchanger

Implementation Method 2

Since the surface of the heat exchanger that draws heat from the environment is cold, the moisture in the ambient air condenses on the heat exchanger

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

a pump that is disposed on the water duct and that enables the water in the drip tray to be delivered to the drying pocket

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 4

the water collected in the drip tray is transferred to the drying pocket, that enables the humid air inside the tub to be condensed after the washing process, thus providing the cooling of the drying pocket

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 5

the drying pocket is cooled by circulating the water in the drip tray through a channel, that is disposed at the lateral surface of the drying pocket

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 6

the channel is bent in serpentine form on the tub surface. By increasing the length of the channel as such, the cold water in the drip tray is discharged after flowing a longer path and by increasing the surface area being cooled, the amount of heat transfer is increased

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3226742B1A heat pump dishwasher
Publication Date: 2018.09.05 ARCELIK AS
  • EP3226742B1 patent drawingFigure 1
  • EP3226742B1 patent drawingFigure 2
  • EP3226742B1 patent drawingFigure 3

AI summary

The present invention relates to a dishwasher (1) comprising a body (2); a tub (3) that is disposed inside the body (2) and wherein the steps of washing, rinsing and drying are realized; a drying pocket (4) that is disposed at least one lateral wall of the tub (3), that is in thermal contact with the tub (3) and that provides the condensation of the humid air inside the tub (3) by being cooled in the drying step; a heat pump (5) that is disposed inside the body (2), that provides the heating of the water to be used in the washing step and that has a first heat exchanger (6) drawing heat from the ambient air, a second heat exchanger (7) transferring the heat received from the first heat exchanger (6) to the wash water and a compressor (8) fluidly connected to the first heat exchanger (6) and the second heat exchanger (7), realizing the refrigerant cycle, and a drip tray (9) that is disposed immediately under the first heat exchanger (6), wherein the water condensing on the first heat exchanger (6) is collected.