Flat-Tube Heat Exchanger Header for Stable Refrigerant Distribution

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Solution Overview

Problem

Conventional heat exchangers with circular cylindrical headers face challenges in efficiently directing refrigerant flow to multiple heat transfer tubes side by side, as nozzles are typically perpendicular to the header's longitudinal direction, requiring additional plate-shaped members and complex connections.

Innovation Solution

A heat exchanger design featuring a liquid header with a unique configuration of plate-shaped members and flow paths that allow refrigerant to be efficiently directed to flat tubes, using a distributor and flow dividing pipes to manage refrigerant flow across multiple tubes, reducing the need for additional components and simplifying connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If nozzles are provided as openings of a plate-shaped member extending perpendicularly to the longitudinal direction of the header, then refrigerant can be supplied to heat transfer tubes, but the device complexity increases due to requiring additional plate-shaped members and connections

Engineering Contradiction:
Improverefrigerant supply to heat transfer tubesVSAvoidnumber of components and connections
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the nozzle function directly into the header by forming openings in the longitudinal direction of the header as nozzles. This integration eliminates the need for separate plate-shaped members with nozzle openings, thereby reducing the number of components and connections while maintaining reliable refrigerant supply to the heat transfer tubes.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If nozzles are perpendicular to the header's longitudinal direction, then refrigerant flow can be directed to tubes, but manufacturing complexity increases

Engineering Contradiction:
Improverefrigerant flow directionVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of providing nozzles perpendicular to the longitudinal direction of the header as in conventional designs, the patent inverts the approach by forming nozzles that extend in the longitudinal direction of the header. This inversion simplifies the manufacturing process by eliminating the need for additional plate-shaped members and complex joining operations, while still achieving effective refrigerant flow direction to the heat transfer tubes.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If multiple plate-shaped members with openings are used as nozzles, then refrigerant distribution is achieved, but the number of components increases

Engineering Contradiction:
Improverefrigerant distributionVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent combines the refrigerant distribution function into the header itself by forming openings in the longitudinal direction as nozzles. This merging eliminates the need for multiple separate plate-shaped members, thereby reducing the quantity of components while maintaining effective refrigerant distribution to all heat transfer tubes.

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 enhances refrigerant flow velocity and distribution, improving heat exchange efficiency while minimizing the number of components and manufacturing complexity, allowing for stable operation with reduced pressure loss and deflected flows.

Implementation Method 1

a nozzle (34y) extending in a direction different from the longitudinal direction of the header (30) in the liquid header (30)... capable of increasing a flow velocity of the refrigerant

Methodology Applied
Scientific EffectNozzle effect: De Laval Nozzle

Implementation Method 2

a plurality of heat transfer tubes (28) connected to a header (30)... heat exchanger and heat pump apparatus

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3992548B1Heat exchanger and heat pump apparatus
Publication Date: 2024.10.30 DAIKIN INDUSTRIES LTD
  • EP3992548B1 patent drawingFigure 1
  • EP3992548B1 patent drawingFigure 2
  • EP3992548B1 patent drawingFigure 3

AI summary

A heat exchanger and a heat pump device that, with a small number of components, are capable of sending a refrigerant in a direction in which a plurality of heat transfer tubes are disposed side by side, the plurality of heat transfer tubes being connected to a header. An outdoor heat exchanger (11) includes a liquid header (30). The liquid header (30) includes a first liquid-side member (31) that includes a liquid-side flat-tube connection plate (31a) to which a plurality of flat tubes (28) are connected, a seventh liquid-side member (37) that includes a liquid-side external plate (37a) positioned on a side opposite to the flat tubes (28), and a fourth liquid-side member (34) that includes a fourth internal plate (34a) positioned therebetween. The fourth internal plate (34a) includes a first penetrationportion (34o) extending in a direction in which the plurality of flat tubes (28) are disposed side by side. The first penetrationportion (34o) has an introduction space (34x), a nozzle (34y), and an ascending space (34z) that are disposed side by side in order in the direction in which the plurality of flat tubes (28) are disposed side by side. The width of the nozzle (34y) is smaller than the width of the introduction space (34x) and is smaller than the width of the ascending space (34z).