Flat-Tube Heat Exchanger Header Partition for Uniform Refrigerant Flow
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Solution Overview
Problem
Conventional heat exchangers with flat tubes and circular header collecting pipes face issues with refrigerant flow rate and wetness variation, leading to inefficient performance as an evaporator due to liquid refrigerant accumulation at the bottom of communication spaces, which reduces the effectiveness of the heat exchange process.
Innovation Solution
The introduction of a partition plate in the upstream communication space that divides it into two areas, allowing for a communication path at the lower portion to increase the refrigerant flow rate by reducing the cross-sectional area and ensuring uniform distribution to the flat tubes, thereby reducing wetness variations and enhancing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the flat tubes are inserted deep inside the communication space to reduce the cross-sectional area of the refrigerant flow path, then the flow rate of the refrigerant is increased, but the cross-sectional area can only be reduced to a certain level and the flow rate cannot be sufficiently increased
Solution Approach 1:
The communication space is divided into a first space and a second space by the partition plate. The first space contains the flat tubes and the second space is the inlet space for refrigerant. This segmentation allows the refrigerant to flow from the second space through the communication path into the first space, effectively reducing the cross-sectional area of the flow path and increasing the refrigerant flow rate without requiring complex design modifications to the header collecting pipe shape.
2Speed
If the shape of the header collecting pipe is changed to reduce the cross-sectional area of the refrigerant flow path, then the flow rate of the refrigerant can be adjusted to an optimum flow rate, but the design requires significant modification which makes it difficult to change the flow rate easily
Solution Approach 1:
Instead of changing the overall shape of the header collecting pipe, the invention segments the communication space internally using a partition plate. This allows the flow path cross-sectional area to be reduced and the refrigerant flow rate to be optimized while maintaining the simple circular cross-section of the header collecting pipe, thereby preserving ease of manufacture and adaptability.
Solution Approach 2:
The partition plate is positioned at a specific location in the communication space to divide it into two spaces. This spatial arrangement in the vertical dimension effectively reduces the flow path cross-sectional area without altering the horizontal cross-section of the header collecting pipe, enabling flow rate optimization while maintaining design simplicity and adaptability.
3Stability of the object's composition
If the refrigerant flows at a slow rate in the communication space, then the liquid refrigerant accumulates at the bottom of the communication space due to gravity, but increasing the flow rate is difficult with conventional structures
Solution Approach 1:
The partition plate divides the communication space into a first space (containing flat tubes) and a second space (inlet space). The communication path connects these two spaces, forcing the refrigerant to flow through a restricted path. This segmentation prevents liquid refrigerant accumulation at the bottom by maintaining adequate flow velocity while ensuring uniform distribution to all flat tubes, thus improving both wetness uniformity and heat exchange performance.
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 configuration significantly increases the refrigerant flow rate and reduces wetness variations, ensuring that the heat exchanger operates effectively by preventing liquid refrigerant accumulation and ensuring uniform distribution to the flat tubes, thus improving overall performance.
Implementation Method 1
the partition plate extends in the vertical direction and divides the upstream communication space into a first space in communication with the plurality of flat tubes and a second space in communication with an inlet portion configured to introduce a refrigerant into the upstream communication space
Implementation Method 2
a communication path, which is located at a lower portion of the upstream communication path, allows the first space and the second space to communicate with each other
Implementation Method 3
When such a heat exchanger functions as an evaporator, a gas-liquid two-phase refrigerant flows into the communication space
Implementation Method 4
configured to exchange heat between a fluid flowing in the flat tubes and air outside the flat tubes
Data Source
AI summary
A heat exchanger includes a plurality of flat tubes arranged one above the other, a plurality of fins connected to the flat tubes, a first header collecting pipe in which one end of each of the plurality of flat tubes is inserted, and a second header collecting pipe in which the other end of each of the plurality of flat tubes is inserted. The heat exchanger exchanges heat between a fluid flowing through the flat tubes and air outside the flat tubes. Each of the first and second header collecting pipes extends in a vertical direction. At least one of the first and second header collecting pipes comprises a communication space that communicates with an upstream side of the plurality of flat tubes when the heat exchanger functions as an evaporator. The communication space comprises a partition plate.