Header Loop Structure for Even Refrigerant Flow in Heat Exchangers
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Solution Overview
Problem
Existing heat exchangers face challenges in minimizing eccentric flow of refrigerant at varying circulation rates, as throttling can either enhance flow velocity too much at high rates or hinder it at low rates, leading to inefficient refrigerant distribution across flat tubes at different heights.
Innovation Solution
A heat exchanger design featuring a loop structure within the header collecting tube, with partition members, inflow ports, upper and lower communicating passages, and flow regulation spaces, which partitions the internal spaces to manage refrigerant flow and ensure even distribution by throttling the passage area and guiding the refrigerant through loop structures to maintain ascension velocity and prevent eccentric flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a throttle is formed inside the header collecting tube to increase flow velocity, then eccentric flow is minimized at low circulation rates, but flow velocity becomes excessively high at high circulation rates causing liquid phase refrigerant to collect at the top
Solution Approach 1:
The patent applies a loop structure that dynamically adapts to different circulation rates. At low circulation rates, the throttle increases flow velocity to prevent eccentric flow. At high circulation rates, the loop structure allows refrigerant to circulate back to lower sections, preventing excessive velocity and liquid collection at the top. This dynamic adaptation resolves the contradiction between maintaining sufficient velocity and preventing excessive velocity.
Solution Approach 2:
The header collecting tube is segmented into multiple sections using partition members, creating distinct flow paths. The loop structure divides the single flow path into multiple circulation loops, allowing different sections to handle different flow rates independently. This segmentation enables the system to manage eccentric flow at low rates while controlling velocity at high rates through distributed flow paths.
2Speed
If the throttle is adjusted to maintain appropriate flow velocity at high circulation rates, then liquid phase refrigerant collection is prevented, but refrigerant cannot reach the top at low circulation rates causing eccentric flow
Solution Approach 1:
The loop structure provides dynamic flow path selection based on circulation rate. At low circulation rates, the throttle restriction is overcome by the loop configuration that guides refrigerant upward. At high circulation rates, the loop allows refrigerant to circulate and redistribute, maintaining appropriate velocity without excessive liquid collection. This dynamic behavior resolves the contradiction between reaching the top and controlling velocity.
3Device complexity
If a simple throttle structure is used, then device complexity is low, but it cannot effectively minimize eccentric flow under varying circulation rate conditions
Solution Approach 1:
The header collecting tube is divided into multiple sections by partition members, creating a segmented structure with loop configurations. This segmentation transforms a simple throttle into a multi-section loop system that can handle varying circulation rates effectively while maintaining reasonable structural complexity. The segmented design enables independent flow management in different sections.
Solution Approach 2:
The loop structure is nested within the header collecting tube, with partition members and communicating passages integrated into the existing tube structure. This nesting approach adds the functionality of eccentric flow minimization across varying conditions without requiring a completely separate system, thereby managing device complexity while improving reliability.
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 minimizes eccentric flow of refrigerant across flat tubes at both low and high circulation rates, ensuring sufficient refrigerant flow to all tubes regardless of the circulation rate, thereby maintaining efficient heat exchange performance.
Implementation Method 1
Passing the refrigerant through the throttle formed in this manner facilitates mixing of the gas phase refrigerant and the liquid phase refrigerant, while at the same time improves the flow velocity
Implementation Method 2
the loop structure includes upper communicating passages which are located in upper parts of the first spaces and the second spaces and provide communication between the upper parts of the first spaces and the second spaces, thereby guiding the refrigerant which has ascended within the first spaces into the second spaces
Data Source
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AI summary
Provided are a heat exchanger and an air conditioning device with which it is possible to minimize eccentric flow of a refrigerant, even in cases of use under conditions in which the circulation rate varies. A plurality of flat perforated tubes (21b) are connected at different heights to a first internal space (23a) of a doubled-back header collecting tube (23) of an outdoor heat exchanger (20). In the first internal space (23a) there is adopted a loop structure including a first partition plate (51), first inflow ports (41x), a first upper communicating passage (51x), and a first lower communicating passage (51y). The first partition plate (51) partitions the first internal space (23a) into a first outflow space (51a) and a first loop space (51b). The first inflow ports (41x) are disposed at the bottom of the first outflow space (51 a), so as to cause the refrigerant to ascend within the first outflow space (51 a). Refrigerant that has reached the top end of the first outflow space (51 a) is guided into the first loop space (51b) via the first upper communicating passage (51x), and refrigerant having descended through the first loop space (51b) is returned to the first outflow space (51 a) via the first lower communicating passage (51y), in a direction other than a vertical direction.