Heat exchanger and air conditioning device

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Solution Overview

Problem

Heat exchangers with flat tubes and header collecting tubes face challenges in suppressing eccentric flow of refrigerant, particularly when refrigerant circulation rates vary, as existing solutions either fail to maintain adequate flow velocity at low rates or cause excessive collection at high rates, leading to inefficient heat exchange.

Innovation Solution

The heat exchanger incorporates a loop structure with partition members that partition the header collecting tube into upper and lower spaces, featuring inflow and communicating passages to manage refrigerant flow, ensuring even distribution and preventing excessive collection, thereby maintaining efficient flow at varying circulation rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a throttle is formed inside the header collecting tube to raise flow velocity and suppress eccentric flow, then eccentric flow is suppressed at low circulation rates, but at high circulation rates the flow velocity becomes too high causing excessive collection of high specific gravity refrigerant at the top, giving rise to eccentric flow

Engineering Contradiction:
Improvesuppression of eccentric flowVSAvoidperformance across varying circulation rates
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The header collecting tube is divided into multiple segments by partition members, creating separate flow paths (first space and second space) that allow independent control of refrigerant distribution to different flat tubes, enabling effective eccentric flow suppression across varying circulation rates

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The throttle opening is made adjustable rather than fixed, allowing the flow velocity to be dynamically controlled to match different circulation rates, thereby maintaining effective eccentric flow suppression whether the circulation rate is low or high

Inventive Principle:
Principle #15Dynamics

2Reliability

If the spaces on the sides of the header collecting tubes are narrowed by partition members to make it easier for refrigerant to reach the top ends, then refrigerant distribution is improved, but the structure complexity increases

Engineering Contradiction:
Improverefrigerant distribution uniformityVSAvoidheader collecting tube structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The header collecting tube is segmented into multiple functional spaces (first space for refrigerant inflow and upward flow, second space for distributing refrigerant to flat tubes) using partition members, which organizes the flow paths and improves refrigerant distribution while keeping the structure manageable

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Partition members are positioned at different heights and locations within the header collecting tube to create a three-dimensional flow control system, allowing refrigerant to be guided through multiple levels and spaces for more uniform distribution

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

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 suppresses eccentric flow and ensures sufficient refrigerant distribution to flat tubes at different heights, maintaining efficient heat exchange performance across low and high circulation rates.

Implementation Method 1

The header collecting tube has a loop structure. The loop structure includes a first partition member and a second partition member, an inflow port, an upper communicating passage, and a lower communicating passage.

Methodology Applied
Scientific EffectLoop circulation:

Implementation Method 2

The inflow port is formed on the first partition member at the bottom part of the first space, and the inflow port allow refrigerant to pass from the lower internal space to the upper internal space so that an ascending flow arises in the first space

Methodology Applied
Scientific EffectAscending flow: Free Convection

Implementation Method 3

refrigerant that has passed the partition members can be returned via underneath he partition members to the spaces on the sides where the flat tubes are provided, whereby it is possible to avoid situations in which too much refrigerant of high specific gravity collects in the tops of the header collecting tubes

Methodology Applied
Scientific EffectGravity-driven flow: Gravitation

Data Source

PatentEP3088833B1Heat exchanger and air conditioning device
Publication Date: 2018.02.14 DAIKIN INDUSTRIES LTD
  • EP3088833B1 patent drawingFigure 1
  • EP3088833B1 patent drawingFigure 2
  • EP3088833B1 patent drawingFigure 3

AI summary

Provided are a heat exchanger and an air conditioning apparatus with which it is possible to suppress eccentric flow of refrigerant, even when employed under conditions in which the circulation rate varies. A plurality of flat multi-perforated tubes (21 b, 121 b) are connected at different heightwise locations in a first internal space (23a) of a doubled-back header collecting tube (23) of an outdoor heat exchanger (20). For the first internal space (23a), a loop structure is adopted including a first partition plate (51), and first inflow port (41x), a first upper communicating passage (51x), and a first lower communicating passage (51y) for allowing the refrigerant to ascend within a first outflow space (51 a). The first internal space is partitioned by a first flow regulation plate (41), the first partition plate (51), and a first blocking plate (61) into the first outflow space (51 a), a first loop space (51b), a first inflow space (61b), and a first ascension space (61a). The refrigerant passage of the flat tube (121b) that is connected to the first inflow space (61b), and a lower communicating port (61x) linking the first inflow space (61b) and the first ascension space (61 a), are arranged so as to not overlap each other.