Dishwasher with heat pump

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Solution Overview

Problem

Current dishwashers face challenges in achieving optimal energy efficiency due to complex heat exchange structures that are difficult to clean and can impede water drainage, limiting the effectiveness of heat transfer between the tub and process water.

Innovation Solution

Incorporating a heat pump with a condenser and evaporator arrangement on the tub's wall and circulating pump chamber, allowing direct heat input or extraction without additional devices, and thermally coupling the evaporator to the drain area for efficient heat transfer from waste water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a heat exchanger is provided to extract heat from the tub and feed it into the fresh water, then energy efficiency is improved, but the structure becomes complex and difficult to clean

Engineering Contradiction:
Improveenergy efficiencyVSAvoidstructure complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent combines the heat exchanger function with the existing circulating pump by arranging the condenser on the pump chamber wall. This integration eliminates the need for separate heat exchange devices inside the tub, reducing structural complexity while maintaining energy efficiency through direct heat transfer to the circulating process water.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The circulating pump chamber wall serves dual functions: it acts as both the pump housing structure and the heat exchange surface. By making the pump chamber wall part of the heat exchange system, the design achieves multi-functionality, improving energy efficiency without adding separate components that would increase complexity.

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

2Temperature

If heat exchange devices are added to the tub wall, then heat transfer efficiency is improved, but water drainage is impeded and cleaning becomes difficult

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidcleaning ease
Core Design Contradiction:
TemperatureVSEase of operation

Solution Approach 1:

The patent extracts the heat exchange function from the tub wall interior and relocates it to the external surface of the circulating pump chamber. This extraction removes potential obstacles from the tub interior, ensuring unimpeded water drainage and easy cleaning of the tub surface while maintaining effective heat transfer through the pump chamber wall.

Inventive Principle:
Principle #2Taking out (Extraction)

3Temperature

If the condenser is arranged on the circulating pump chamber wall, then heat transfer to process water is enhanced, but the pump structure becomes more complex

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidpump structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The condenser is integrated with the pump chamber wall rather than being a separate component. This merging of the heat exchange element with the pump structure allows heat transfer enhancement while minimizing additional structural complexity, as the condenser utilizes the existing pump chamber wall surface.

Inventive Principle:
Principle #5Merging (Combining)

4Loss of energy

If the evaporator is thermally coupled to the drain area, then heat extraction from waste water is improved, but the drain structure becomes more complex

Engineering Contradiction:
Improveheat recovery efficiencyVSAvoiddrain structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The drain area structure serves dual functions as both the drainage pathway and the heat exchange surface. By thermally coupling the evaporator to the drain area, the design achieves multi-functionality, enabling heat recovery from waste water without requiring separate heat exchange devices that would increase drain structure complexity.

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 configuration enhances energy efficiency by simplifying the structure, improving heat transfer efficiency, and reducing the need for complex components that are hard to clean, while allowing for effective heat management across various dishwasher phases.

Implementation Method 1

a first condenser (8) arranged on a circulating pump (25)... the process water can be heated

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the evaporator or (if there are several evaporators) at least one of the evaporators is thermally coupled to the drain area through which water is discharged from the tub to the sewage system after use. In this way, heat can be extracted from the waste water.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

at least one expansion valve (9a, 9b) to at least one evaporator (10a, 10b), where the medium evaporates while absorbing heat

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

from which a heat pump medium is pumped to one or more condensers (8), where liquefaction takes place with the release of heat

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP2215954B1Dishwasher with heat pump
Publication Date: 2017.05.17 V-ZUG AG
  • EP2215954B1 patent drawingFigure 1~2
  • EP2215954B1 patent drawingFigure 3~4
  • EP2215954B1 patent drawingFigure 5~6

AI summary

The dishwasher has a tub (1) receiving rinsing items, and a heat pump with a condenser (8) and an evaporator (10a) arranged such that heat is extracted/supplied to process water in the tub. A circulation pump (25) delivers the water from a sump (2) to spraying arms of the dishwasher underneath the tub by a transfer-pumping line system (26). A condenser (8) at the sump is arranged at the circulation pump and/or at the transfer-pumping line system. The condenser has a piping, which runs in a meandering pattern. An independent claim is also included for a method for operating a dishwasher.