Heat Pump Dishwasher Capillary Cooling to Reduce Energy Consumption

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Solution Overview

Problem

The heat pump system in dishwashers experiences reduced heating performance and increased energy consumption due to the capillary overheating, which impairs the evaporator's ability to draw heat efficiently, leading to longer washing program durations.

Innovation Solution

The capillary is cooled using cold water condensing in the evaporator, either directly or through a condensation receptacle, to maintain its temperature and prevent overheating, thereby enhancing the heat pump's performance and reducing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If the capillary is positioned in ambient air during heat pump operation, then the heat pump system can operate continuously, but the capillary draws heat from the environment causing the evaporator to heat up more than necessary, decreasing heat drawing capacity and increasing energy consumption

Engineering Contradiction:
Improveheat pump operation continuityVSAvoidenergy consumption
Core Design Contradiction:
Duration of action of stationary objectVSUse of energy by moving object

Solution Approach 1:

The patent introduces cold water from the condensation receptacle as an intermediary cooling medium for the capillary. This cold water acts as a mediator that absorbs excess heat from the capillary, preventing it from drawing heat from the environment during operation. The capillary is positioned in thermal contact with the cold water, allowing heat transfer from the capillary to the cooling water, thereby maintaining the evaporator's heat drawing capacity while ensuring continuous operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the capillary draws heat from the environment, then the system maintains operational continuity, but the evaporator's capacity to draw heat decreases, reducing heating performance

Engineering Contradiction:
Improvesystem operational continuityVSAvoidheating performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent converts the harmful effect of the capillary drawing heat from the environment into a beneficial cooling effect. The cold water from the condensation receptacle, which would otherwise be wasted, is utilized to cool the capillary. This transforms the waste cold water into a useful cooling resource that prevents the capillary from overheating and maintains the evaporator's heat drawing capacity, thereby improving heating performance while maintaining operational continuity.

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

3Device complexity

If the capillary temperature increases during operation, then the system remains simple in structure, but the washing program duration increases due to reduced heating efficiency

Engineering Contradiction:
Improveheat pump structure simplicityVSAvoidwashing program duration
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent makes the cold water from the condensation receptacle serve multiple functions: it collects condensation from the evaporator and simultaneously cools the capillary. This multi-functional use of the same water resource allows the system to maintain simple structure without additional cooling components while improving heating efficiency and reducing washing program duration through effective capillary cooling.

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

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 cooling of the capillary allows the evaporator to draw more heat from the environment, improving heating performance and reducing energy usage by ensuring the refrigerant remains cold, thus shortening washing cycles and lowering energy consumption.

Implementation Method 1

The capillary decreases the temperature of the fluid between the condenser and the evaporator. While flowing through the capillary which has a very narrow cross-section, the fluid loses pressure and cools down.

Methodology Applied
Scientific EffectPressure reduction cooling: Joule-Thomson Effect

Implementation Method 2

the capillary draws heat from the environment, thus cannot decrease the temperature of the fluid

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

The evaporator in the heat pump system draws heat from the environment

Methodology Applied
Scientific EffectHeat absorption: Heat Exchanger

Implementation Method 4

the compressor pressurizes the fluid so as to enable the same to heat up

Methodology Applied
Scientific EffectCompression heating: Compression

Implementation Method 5

the condenser transfers heat to the washing water

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP3855997B1A heat pump dishwasher with reduced energy consumption
Publication Date: 2024.02.07 ARCELIK AS
  • EP3855997B1 patent drawingFigure 1
  • EP3855997B1 patent drawingFigure 2
  • EP3855997B1 patent drawingFigure 3

AI summary

The present invention relates to a heat pump (6) type dishwasher (1), comprising a compressor (7) which performs the refrigerant cycle, a condenser (8) which is used for heating the washing water, an evaporator (9) which draws heat from the outer environment and transfers the same to the condenser (8) by means of the compressor (7), a capillary (10) which is disposed between the condenser (8) and the evaporator (9), a refrigerant line (11) composed of flow pipes wherein the refrigerant fluid flows, at least one fan (12) which provides the heat transfer by blowing the ambient air onto the evaporator (9), and a condensation receptacle (13) wherein the water condensing on the evaporator (9) is collected.