Heat exchanger
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Solution Overview
Problem
The existing parallel flow heat exchangers exhibit varying heat exchange performances across different flow paths, with some paths having low efficiency, leading to overall suboptimal performance and increased flow resistance.
Innovation Solution
Incorporating a communicating passage between certain spaces in the header pipes allows a portion of the refrigerant to bypass certain flow paths, reducing flow resistance and enhancing fluid state parameters in more efficient paths, thereby improving overall heat exchange performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If imperforate baffles are used to separate header pipe spaces, then flow paths are defined and refrigerant distribution is controlled, but flow resistance increases and heat exchange performance deteriorates in certain paths
Solution Approach 1:
The header pipe spaces are segmented into multiple regions using baffles, and communicating passages are introduced to create selective connectivity between segments. This segmentation allows different refrigerant flows to be directed through different paths, optimizing heat exchange performance while managing flow resistance through strategic segmentation rather than complete isolation.
Solution Approach 2:
Communicating passages act as intermediary channels between header pipe spaces that are separated by imperforate baffles. These passages allow controlled refrigerant flow between compartments, reducing flow resistance and improving heat exchange performance without compromising the structural separation provided by the baffles.
2Productivity
If refrigerant flows through all defined paths, then comprehensive heat exchange occurs, but flow resistance increases and overall efficiency decreases
Solution Approach 1:
Instead of requiring refrigerant to flow through all possible paths, the communicating passages enable partial flow through alternative routes. This partial action principle allows the system to achieve sufficient heat exchange capacity through optimized paths while avoiding the excessive flow resistance that would result from forcing complete circulation through all paths.
Solution Approach 2:
The introduction of communicating passages changes the flow parameters (pressure distribution, flow velocity, flow direction) within the header pipe system. These parameter changes enable refrigerant to follow more efficient flow paths, reducing overall flow resistance while maintaining or enhancing heat exchange capacity through optimized flow distribution.
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 reduces flow resistance and increases heat exchange capacity in more efficient paths, resulting in improved overall heat exchange performance while maintaining or slightly reducing heat exchange performance in less efficient paths.
Implementation Method 1
a communicating passage for communicating the first space with the second space, and when the refrigerant flows from the first space of the first header pipe to the second header pipe along the flat tubes, a part of the refrigerant passes through the communicating passage to directly enter into the second space of the first header pipe
Implementation Method 2
The corrugated or louvered fins are provided between adjacent micro-channel flat tubes to improve the heat exchange efficiency between the heat exchanger and the air
Implementation Method 3
a parallel flow heat exchanger has characteristics, such as a high cooling efficiency, a small size and a light weight
Data Source
AI summary
A heat exchanger includes a first header pipe, a second header pipe, a third header pipe, a fourth header pipe and a plurality of flat tubes, the first header pipe is provided with a first space and a second space and a communicating passage for communicating the first space with the second space; when refrigerant flows from the first space of the first header pipe to the second header pipe along the flat tubes, a part of the refrigerant passes through the communicating passage and directly enters into the second space of the first header pipe, thus an overall flow resistance of the heat exchanger may be decreased to some extent. Besides, the flow quantity of the refrigerant in the third flow path is constant, however fluid state parameters may change, which may greatly improve the heat exchange capacity of the third flow path, thereby improving the heat exchange performance of the heat exchanger on the whole.