Coaxial Dishwasher Condenser Layout to Prevent Solid Deposition

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Solution Overview

Problem

Dishwashers with heat pump systems face issues with condenser clogging due to solids in the washing liquor, leading to reduced heat transfer performance and increased energy consumption.

Innovation Solution

The dishwasher design features coaxially arranged tubes for the refrigerant and washing liquor, where the refrigerant surrounds the washing liquor, preventing solid accumulation and optimizing heat transfer without additional heat transfer paths, thus maintaining energy efficiency and low water consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional condenser is used to heat washing liquor, then heat transfer performance is initially good, but solids in the washing liquor deposit on the condenser walls and reduce heat transfer performance over time

Engineering Contradiction:
Improveheat transfer performanceVSAvoidsolid deposition
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent implements a coaxial tube configuration where the condenser tube is nested within the washing liquor supply tube. The washing liquor flows through the outer tube while the refrigerant flows through the inner condenser tube. This nested arrangement allows the washing liquor to flow around the condenser, preventing solid deposition on the condenser surface while maintaining efficient heat transfer.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If additional heat transfer paths are added to prevent solid accumulation, then heat transfer reliability improves, but device complexity increases

Engineering Contradiction:
Improveheat transfer performanceVSAvoidheat transfer path configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the washing liquor supply tube serve dual functions: it acts as both the supply path for washing liquor to the spray devices and as the outer protective tube for the condenser. This multi-functional design eliminates the need for separate heat transfer paths while preventing solid accumulation, thereby maintaining reliability without increasing device complexity.

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

3Use of energy by moving object

If the condenser is placed in the washing liquor flow path, then heat transfer efficiency improves, but water consumption increases due to additional filling requirements

Engineering Contradiction:
Improveenergy efficiencyVSAvoidwater consumption
Core Design Contradiction:
Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The patent merges the condenser heat transfer function with the existing washing liquor supply tube by creating a coaxial structure. The washing liquor flows through the annular space between the inner condenser tube and outer supply tube, combining the heat transfer path with the existing water supply infrastructure. This eliminates the need for additional water-filled paths while maintaining energy efficiency.

Inventive Principle:
Principle #5Merging (Combining)

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 design effectively prevents condenser clogging, ensures high energy efficiency, and reduces water usage by utilizing existing paths for heat transfer, enhancing the overall performance of the dishwasher.

Implementation Method 1

condensing water vapor from the supply air

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

thermal energy extracted from the room air is transferred to a working medium

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

the working medium is compressed by the compressor and thus brought to a higher temperature level

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

the hot refrigerant condenses on the condenser and heats up the wash water

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP2682039B1Dishwasher with a heat pump
Publication Date: 2016.08.24 MIELE & CO KG
  • EP2682039B1 patent drawingFigure 1~2
  • EP2682039B1 patent drawingFigure 3~5
  • EP2682039B1 patent drawingFigure 6

AI summary

The dishwasher (1) has a rinsing chamber (18) in which two spraying facilities are rotatably arranged at spray arms (20a, 20b) for washing goods with rinsing water. A heat pump circuit heats the rinsing water and a condenser (12) that comprises a refrigerant pipe and a rinsing water pipe arranged coaxial to each other, where the rinsing water pipe is arranged within the refrigerant pipe. The condenser is arranged in a flow direction of the rinsing water between a water diverter (19c) and the spray arms.