Evaporator Inlet Pipe Constriction for Lower Refrigerant Flow Noise

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Solution Overview

Problem

Refrigerant injection into evaporators in refrigeration appliances generates significant flow noises due to the large diameter difference between the throttle element and the inlet pipe, which existing technologies have not adequately addressed.

Innovation Solution

The evaporator design incorporates a concave curvature and constriction areas within the inlet pipe to alter the refrigerant flow, reducing noise through a stepped cross-sectional geometry and chamber formation, while maintaining rigidity and material efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the inlet pipe has a large inside diameter to accommodate refrigerant flow, then the flow capacity is improved, but flow noise increases due to the diameter difference with the throttle element

Engineering Contradiction:
Improverefrigerant flow capacityVSAvoidflow noise
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The inlet pipe is divided into multiple sections with different cross-sectional areas: a first section with larger area for high flow capacity, and a second section with smaller area (constriction) to reduce noise. This segmentation allows the pipe to simultaneously achieve both high productivity and low noise by creating distinct functional zones within the same component.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inlet pipe applies local quality changes by introducing a constriction area at a specific location downstream of the throttle element. This local modification creates a chamber that buffers the refrigerant flow and reduces noise generation at the injection point, while the rest of the pipe maintains its larger diameter for adequate flow capacity.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If the inlet pipe cross-section is reduced to reduce noise, then flow noise is reduced, but the flow capacity and heat exchange efficiency decrease

Engineering Contradiction:
Improveflow noiseVSAvoidrefrigerant flow capacity
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The inlet pipe is divided into multiple sections with different cross-sectional areas: a first section with larger area for high flow capacity, and a second section with smaller area (constriction) to reduce noise. This segmentation allows the pipe to simultaneously achieve both high productivity and low noise by creating distinct functional zones within the same component.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The noise reduction is achieved not by uniformly reducing the pipe diameter, but by creating a three-dimensional chamber structure through local constriction. This dimensional approach allows the pipe to maintain large cross-sectional area for flow capacity while introducing volume variations that buffer and dampen noise generation.

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

3Object-generated harmful factors

If the inlet pipe geometry is modified to reduce noise, then noise behavior improves, but manufacturing complexity increases

Engineering Contradiction:
Improveflow noiseVSAvoidevaporator geometry
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The noise reduction chamber is merged with the inlet pipe structure itself, rather than being a separate component. The constriction area is formed as an integral part of the pipe geometry, combining the flow conduit and noise buffering functions into a single unified structure that simplifies manufacturing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inlet pipe serves multiple functions: it conducts refrigerant flow, provides structural support, and acts as a noise buffering chamber. By making the pipe multi-functional, the design avoids adding separate noise reduction components, thereby reducing overall device complexity while achieving noise reduction.

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 design effectively reduces flow noise at the injection point, improves noise behavior, and allows for cost-effective production with precise manufacturing tolerances, enhancing the overall performance of the refrigeration device.

Implementation Method 1

a chamber is formed in the inlet pipe by the constriction area. This achieves the technical advantage, for example, that the chamber forms a buffer space for the inflowing refrigerant and noise development is further reduced.

Methodology Applied
Scientific EffectPressure equalization:

Implementation Method 2

an evaporator for evaporating a refrigerant

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

evaporating a refrigerant

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Data Source

PatentEP2984420B1Refrigeration device comprising an evaporator
Publication Date: 2019.07.17 BSH HAUSGERATE GMBH
  • EP2984420B1 patent drawingFigure 1
  • EP2984420B1 patent drawingFigure 2
  • EP2984420B1 patent drawingFigure 3

AI summary

The present invention relates to a refrigeration device having an evaporator (103) for evaporating a refrigerant, which evaporator comprises an inlet pipe (105) for the admission of the refrigerant, in which inlet pipe there is formed a pipe region (107), which has a first flow cross section, and a constriction region (109), which has a second flow cross section smaller than the first flow cross section, and to a method for producing an evaporator of said type.