Dishwasher comprising heat pump system

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Solution Overview

Problem

Existing dishwasher heat pump systems require a significant cooldown period after a cycle, making it impossible to start a new dishwashing program until the working medium reaches a suitable temperature, which increases energy consumption and cycle duration.

Innovation Solution

Incorporating an additional condenser to heat the cooled medium during the drying phase, a second evaporator for dehumidifying air, and a valve system to switch between configurations, allowing for efficient temperature recovery and reduced cycle time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a basic heat pump system is used to heat dishing water, then energy consumption is reduced, but the working medium becomes too cold after the cycle to start a new program

Engineering Contradiction:
Improveenergy consumptionVSAvoidcooldown period
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The heat pump system is designed to perform multiple functions: during the dishing phase it heats water using the first condenser, and during the drying phase it rapidly heats the working medium using the second condenser. This multi-functionality allows the same system to both reduce energy consumption during washing and enable quick restart by recovering the working medium temperature during drying.

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

Solution Approach 2:

The system begins heating the working medium during the drying phase, which is performed anyway in the dishwasher cycle. By utilizing the second condenser to preheat the working medium during this phase, the system prepares for the next cycle in advance, reducing the cooldown period before the next dishing program can start.

Inventive Principle:
Principle #10Preliminary action

2Temperature

If the working medium is cooled to very low temperatures during the dishing phase, then heating efficiency is improved, but the system cannot start a new program until the medium warms up

Engineering Contradiction:
Improveworking medium temperatureVSAvoidcycle turnover rate
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The heat pump system operates continuously throughout the entire dishwasher cycle without interruption. During the dishing phase, it cools the working medium to achieve efficient heating; during the drying phase, it immediately switches to heating the working medium using the second condenser. This continuous operation ensures both efficient water heating and rapid preparation for the next cycle, maintaining high productivity.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system changes the operational parameters of the heat pump by switching between two condensing modes. The first condenser operates at parameters optimized for heating dishing water, while the second condenser operates at parameters optimized for rapidly heating the working medium. This parameter change allows the system to optimize performance for different phases of the cycle.

Inventive Principle:
Principle #35Parameter changes

3Loss of time

If an additional condenser and valve system are added to enable rapid temperature recovery, then cycle time is reduced, but device complexity increases

Engineering Contradiction:
Improvetime to start new programVSAvoidheat pump arrangement
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The heat pump system is segmented into two distinct functional paths: one with the first condenser for water heating during the dishing phase, and another with the second condenser for working medium heating during the drying phase. This segmentation allows independent optimization of each function while using a unified evaporator and compressor, reducing the complexity increase compared to having completely separate systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The valve system acts as an intermediary that directs the flow of the working medium between the two condensing paths. Rather than requiring complex control mechanisms, the valves provide a simple flow direction change that enables the system to switch between heating modes, managing the complexity of the multi-functional arrangement.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables rapid temperature recovery of the working medium, shortening the time to start a new dishwashing program and improving drying efficiency by preheating air and water, thus reducing overall energy consumption and cycle duration.

Implementation Method 1

a first condenser (32), arranged to heat the working medium

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

a first evaporator (33), arranged to cool the working medium to a very low temperature, possibly to a solid state

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

a compressor (31), arranged to compress the working medium

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

a second condenser (34)... arranged to heat the cooled medium to return the medium to a temperature at least close to room temperature

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 5

a second evaporator (36)... arranged to, during the second phase, generate a flow of humid air from the washing chamber past the second evaporator arranged to condensate water in the humid air

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3082555B1Dishwasher comprising heat pump system
Publication Date: 2017.12.13 ELECTROLUX APPLIANCES
  • EP3082555B1 patent drawingFigure 1
  • EP3082555B1 patent drawingFigure 2
  • EP3082555B1 patent drawingFigure 3

AI summary

The present invention relates to a dishwasher (20; 40) comprising: a washing chamber (21; 41) in which dishing goods are packed in one or more baskets (22, 23); a water circulation system (24); and a heat pump system (30) comprising a compressor (31), a first condenser (32), a second condenser (34) and a first evaporator (33); wherein the heat pump system (30) is switchable between a first configuration used during a dishing phase and in which the compressor (31) is connected to the first condenser (32) arranged to heat the dishing water and a first evaporator (33) arranged to cool a working medium, and a second configuration used during the drying phase and in which the compressor (31) is connected to the second condenser (34) arranged to heat the cooled working medium to prepare the dishwasher for the next dishing phase.