Washing machine with heat pump

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Solution Overview

Problem

Conventional washing machines with heat pumps face inefficiencies in heating water due to limited temperature differences between heat exchangers, leading to suboptimal energy usage and increased energy consumption.

Innovation Solution

The use of at least two heat storage media with different melting points in a washing machine's heat pump system, where one media's latent heat is exploited alongside the sensible heat from the other, enhancing the heat pump's efficiency by maintaining a higher evaporation temperature and reducing compression work.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a single heat storage media is used in the heat pump system, then the system structure is simple, but the heat pump efficiency is limited due to restricted temperature difference between heat exchangers

Engineering Contradiction:
Improveheat pump efficiencyVSAvoidheat storage media configuration
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The heat storage means is segmented into multiple compartments, each containing a different heat storage media with distinct melting points. This segmentation allows the heat pump to access heat at different temperature levels, improving the temperature difference between evaporator and condenser, thereby enhancing heat pump efficiency without excessive structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different heat storage media are selected with varying melting points (e.g., water at 0°C, salt hydrates at higher temperatures) to create a gradient of available heat temperatures. This parameter change in melting points enables the refrigerant to evaporate at optimized temperatures, improving the heat pump's coefficient of performance while maintaining manageable system complexity.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the heat storage media is cooled to low temperatures to maximize latent heat utilization, then more latent heat is available, but the mass flow rate of refrigerant decreases

Engineering Contradiction:
Improvelatent heat availabilityVSAvoidrefrigerant mass flow rate
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The heat storage means is divided into multiple compartments with different heat storage media having progressively higher melting points. This segmentation allows the system to utilize latent heat from multiple phase transitions at different temperature levels, ensuring sufficient latent heat availability while maintaining higher average temperatures that support adequate refrigerant mass flow rate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat storage means employs a composite configuration of multiple heat storage media (e.g., water, salt hydrates, paraffin) with complementary melting points. This composite approach ensures that as one media completes its phase transition, another media at a higher temperature level provides continued latent heat release, maintaining both heat quantity and temperature for optimal refrigerant flow.

Inventive Principle:
Principle #40Composite materials

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 configuration increases the heat pump's efficiency by utilizing latent heat throughout the operation, reducing energy consumption and improving the mass flow rate of the refrigerant, thereby enhancing the overall energy efficiency of the washing machine.

Implementation Method 1

the latent heat of which is exploited

Methodology Applied
Scientific EffectLatent heat: Latent Heat

Implementation Method 2

two different temperatures of phase transition to solid

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

the second heat exchanger being adapted to cool said refrigerant and to heat process water

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2992132B1Washing machine with heat pump
Publication Date: 2020.02.26 ELECTROLUX APPLIANCES
  • EP2992132B1 patent drawingFigure 1
  • EP2992132B1 patent drawingFigure 2~4
  • EP2992132B1 patent drawingFigure 5

AI summary

A washing machine (1) comprising: - a chamber (10) for receiving goods to be washed, - a heat pump (15) comprising a circuit (101-108) comprising a refrigerant, a first heat exchanger (30, 101), and a second heat exchanger (40, 102), wherein the first heat exchanger (30, 101) is adapted to heat said refrigerant and to cool a heat storage means (30), and the second heat exchanger (40, 102) is adapted to cool said refrigerant and to heat process water to be used in the chamber (10).