Heat Exchanger Header Conduit Layout for Uniform Refrigerant Mixing

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Solution Overview

Problem

Heat exchangers in vehicle air conditioning systems face heterogeneous refrigerant fluid distribution, leading to disparities in heat exchange and temperature management, particularly due to the separation of liquid and gas phases, which complicates thermal management and causes temperature differences in the passenger compartment.

Innovation Solution

A refrigerant fluid distribution device with an external and internal conduit system, where the internal conduit has a portion of reduced thickness and a single communication orifice, allowing for improved mixing and distribution of the liquid and gas phases, reducing head losses and enhancing uniform fluid circulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conduit with multiple small orifices is used to spray refrigerant fluid, then fluid distribution is improved, but head losses increase significantly

Engineering Contradiction:
Improvefluid distributionVSAvoidhead losses
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The distribution device is segmented into an internal conduit and an external conduit, with the internal conduit containing a single communication orifice that opens into the external conduit. This segmentation allows the refrigerant to be introduced at one point and then distributed along the length of the external conduit, avoiding the need for multiple small orifices while still achieving homogeneous distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The internal conduit acts as an intermediary element that introduces refrigerant into the external conduit through a single communication orifice. The refrigerant then travels along the external conduit, allowing for gradual distribution without passing through multiple restrictive orifices, thus reducing head losses while maintaining distribution effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If multiple small orifices are used for refrigerant distribution, then fluid mixing is improved, but the system complexity increases

Engineering Contradiction:
Improvefluid mixingVSAvoidsystem complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The distribution device is segmented into an internal conduit and an external conduit, with the internal conduit containing a single communication orifice that opens into the external conduit. This segmentation allows the refrigerant to be introduced at one point and then distributed along the length of the external conduit, avoiding the need for multiple small orifices while still achieving homogeneous distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design achieves homogeneous refrigerant distribution along the heat exchanger tubes by using a single communication orifice that opens into the external conduit. The refrigerant flows along the external conduit, ensuring uniform distribution without requiring multiple orifices, thus simplifying the system while maintaining compositional homogeneity.

Inventive Principle:
Principle #33Homogeneity

3Productivity

If diphase refrigerant fluid is admitted to the heat exchanger, then heat exchange efficiency is improved, but phase separation causes heterogeneous feeding

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidphase separation
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The internal conduit acts as an intermediary element that introduces refrigerant into the external conduit through a single communication orifice. The refrigerant then travels along the external conduit, allowing for gradual distribution without passing through multiple restrictive orifices, thus reducing head losses while maintaining distribution effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design achieves homogeneous refrigerant distribution along the heat exchanger tubes by using a single communication orifice that opens into the external conduit. The refrigerant flows along the external conduit, ensuring uniform distribution without requiring multiple orifices, thus simplifying the system while maintaining compositional homogeneity.

Inventive Principle:
Principle #33Homogeneity

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

The solution ensures better distribution and mixing of refrigerant phases, reducing head losses and achieving more uniform heat exchange, thereby improving thermal management and reducing temperature disparities in the vehicle passenger compartment.

Implementation Method 1

The internal conduit comprises at least one communication orifice having an axis intersecting a principal lengthwise axis of the internal conduit

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

the external conduit comprising spraying orifices each having an axis intersecting a principal lengthwise axis of the external conduit

Methodology Applied
Scientific EffectSpray: Spray

Implementation Method 3

the internal conduit comprises a portion of reduced thickness formed by removal of material from an external face of the internal conduit... enables an increase in the size of the communication volume between the internal conduit and the external conduit, which allows the refrigerant fluid passing through the communication orifice or orifices to be distributed better along the communication volume, whether in terms of fluid circulation or of mixing a liquid phase and a gas phase of the refrigerant fluid

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3707455B1Refrigerant fluid distribution device intended to be accommodated in a header of a heat exchanger
Publication Date: 2023.06.21 VALEO SYST THERMIQUES SAS
  • EP3707455B1 patent drawingFigure 1~2
  • EP3707455B1 patent drawingFigure 3~4
  • EP3707455B1 patent drawingFigure 5~6

AI summary

The invention concerns a device for distribution of a refrigerant fluid in a header of a heat exchanger comprising at least two conduits (12, 13), an external conduit (12) and an internal conduit (13), with the internal conduit accommodated in the external conduit in such a manner as to form a volume (14) for communication between the internal conduit and the external conduit, the external conduit comprising spraying orifices (120) each having an axis (120A) intersecting a principal lengthwise axis (12A) of the external conduit, the internal conduit comprising at least one communication orifice having an axis intersecting a principal lengthwise axis of the internal conduit. According to the invention, the internal conduit (13) comprises a portion (16) of reduced thickness formed by removal of material from an external face of the internal conduit (13), the external face facing toward the external conduit (12).