Refrigerator Evaporator Plate Layout for Overflow-Free Refrigerant Flow

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Solution Overview

Problem

Existing household refrigeration appliances face challenges in ease of assembly, manufacturing quality, and energy efficiency of evaporator plates on rear surfaces of container walls for refrigerated goods, particularly in ensuring effective refrigerant flow and preventing refrigerant overflow.

Innovation Solution

The design incorporates a refrigerant circuit system with multiple evaporator plates oriented differently on container walls, featuring evaporator tube sections that adapt to the container's geometry, including sections oriented against the ceiling, bottom, and rear walls, with webs connecting plates to reduce bending effort and prevent air inclusions, thus enhancing refrigerant flow and reducing pressure losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the evaporator tube is laid along multiple differently oriented evaporator plates (ceiling, bottom, rear wall), then the refrigeration coverage and heat exchange efficiency are improved, but the tube routing complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveevaporator plate positioning accuracyVSAvoidevaporator tube routing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The evaporator tube is divided into multiple sections (first evaporator tube section, second evaporator tube section, third evaporator tube section) that can be independently routed along different evaporator plates. Each section connects to the next at transition points, allowing the tube to adapt to the three-dimensional arrangement of evaporator plates on ceiling, bottom, and rear wall surfaces without requiring a single complex continuous route.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The evaporator tube routing transitions from two-dimensional planar paths to three-dimensional spatial paths by connecting evaporator plates on different surfaces (ceiling, bottom, rear wall) through vertical or inclined transitions. This multi-dimensional arrangement allows comprehensive coverage of the storage space while maintaining manageable tube sections.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If the evaporator plates are tightly fitted to all container wall surfaces, then the heat exchange efficiency is improved, but the assembly difficulty and risk of air inclusions increase

Engineering Contradiction:
Improveevaporator plate fitting qualityVSAvoidassembly ease
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The evaporator system is divided into multiple separate evaporator plates (ceiling plate, bottom plate, rear wall plate) that can be independently manufactured and assembled. This segmentation allows each plate to be optimally fitted to its specific surface without requiring the entire evaporator system to be assembled as one complex unit, reducing air inclusion risks and simplifying assembly procedures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each evaporator plate can be pre-formed and pre-positioned independently before final assembly. The tube sections can be pre-routed along each plate, allowing quality control and adjustment to be performed on individual components before they are integrated into the complete evaporator system, thereby improving overall fitting quality while reducing assembly complexity.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If the evaporator tube has frequent directional changes to follow container geometry, then the adaptation to container shape is improved, but the pressure losses and noise increase

Engineering Contradiction:
Improvecontainer geometry adaptationVSAvoidrefrigerant pressure loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The evaporator tube is segmented into distinct sections that follow the geometry of each evaporator plate with minimal directional changes. By dividing the tube into first, second, and third sections corresponding to different evaporator plate locations, each section can be optimized for its specific path, reducing the number of sharp bends and directional changes compared to a single continuous tube following the entire complex geometry.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The evaporator tube routing is designed to minimize elevation changes and gravitational effects on refrigerant flow within each section. By carefully planning the transition between tube sections and their corresponding evaporator plate positions, the system maintains relatively uniform flow conditions that reduce pressure losses from gravitational potential energy variations.

Inventive Principle:
Principle #12Equipotentiality

4Reliability

If the evaporator tube is oriented against gravity in the third section, then refrigerant overflow prevention is improved, but the tube routing complexity increases

Engineering Contradiction:
Improverefrigerant overflow preventionVSAvoidtube section configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The third evaporator tube section is specifically oriented with a directional component counter to gravity, creating a upward or level trajectory that prevents refrigerant from overflowing due to gravitational forces. This anti-gravity orientation acts as a passive safety mechanism, using the tube's physical configuration to counteract the natural downward flow tendency of refrigerant under gravity.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The evaporator tube is divided into functional sections, with the third section specifically designed for overflow prevention on the rear wall evaporator plate. This segmentation allows the overflow prevention function to be isolated to a specific tube section with optimized geometry, while other sections can be designed for optimal heat exchange without being constrained by overflow prevention requirements.

Inventive Principle:
Principle #1Segmentation

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 improves assembly efficiency, reduces noise, enhances refrigeration capacity, and prevents refrigerant overflow, leading to improved energy efficiency and better adaptation to the container's shape, while allowing for flexible production of various evaporator configurations.

Implementation Method 1

the front sides of which rest on differently oriented rear surfaces of the container walls... the rear sides of which are covered with at least one evaporator tube

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

refrigerant circuit system with at least two evaporator plates... in the direction of flow of a refrigerant flowing through the evaporator tube

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2694889B1Domestic refrigerator having a refrigerant circuit system
Publication Date: 2016.08.31 BSH HAUSGERATE GMBH
  • EP2694889B1 patent drawingFigure 1
  • EP2694889B1 patent drawingFigure 2

AI summary

The invention relates to a domestic refrigerator (1) having an internal container (2) which has container walls (2a, 2b, 2c, 2d, 2e) which bound at least one coolable storage space (3, 14) for products to be refrigerated and which have rear surfaces, and having a refrigerant circuit system (4) with at least two evaporator plates (5a, 5b, 5c, 5d, 5e), the front faces of said evaporator plates resting against rear surfaces, which have different orientations, of the container walls (2a, 2b, 2c, 2d, 2e) and the rear faces of said evaporator plates being populated by at least one evaporator tube (10), in the case of which the at least one evaporator tube (10) has a first evaporator tube section (10c) in the direction of flow of a refrigerant which flows through the evaporator tube (10) and is laid along an evaporator plate (5c) which rests against that container wall (2c) which is associated with the top of the storage space (3), and has a second evaporator tube section (10a) which is connected downstream of the first evaporator tube section (10c) in the direction of flow and which is laid along an evaporator plate (5a) which rests against that container wall (2a) which is associated with the base of the storage space (3), and has a third evaporator tube section (10e) which is connected downstream of the second evaporator tube section (10a) in the direction of flow and has a directional component which is oriented against the force of gravity.