Laminated header, heat exchanger and refrigeration cycle device
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Solution Overview
Problem
In laminated headers for heat exchangers, the distribution of refrigerant to heat transfer tubes is often uneven, leading to non-uniform flow rates and reduced heat exchange performance, particularly when the heat exchanger acts as an evaporator.
Innovation Solution
A laminated header design featuring a distribution flow passage with linearly extending flow passages and branching passages that ensure refrigerant flows in opposite directions through certain passages, maintaining a uniform distribution ratio by allowing refrigerant to flow in reverse directions and branching into multiple paths, thereby preventing uneven refrigerant distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the refrigerant repeatedly branches in the distribution flow passage, then the refrigerant can be distributed to multiple heat transfer tubes, but the liquid refrigerant becomes uneven and flows out nonuniformly from the outlet flow passages
Solution Approach 1:
The distribution flow passage is divided into multiple linear flow passages (first, second, third flow passages) that extend in the lamination direction of plates. Each linear flow passage is further segmented into multiple sub-flow passages through branching flow passages, creating a hierarchical segmentation structure that maintains uniform flow distribution while enabling multi-directional refrigerant distribution to heat transfer tubes
Solution Approach 2:
The flow passages extend in the lamination direction (thickness direction) of the plates rather than in the planar direction. This dimensional change allows the refrigerant to flow linearly through the thickness of the laminated structure, preventing uneven liquid film formation and ensuring uniform flow distribution at the outlets while still providing distribution to multiple heat transfer tubes
2Quantity of substance
If the distribution flow passage branches repeatedly to supply refrigerant to multiple heat transfer tubes, then the coverage is improved, but the flow uniformity deteriorates
Solution Approach 1:
The distribution system is segmented into multiple linear flow passages extending in the lamination direction, with each linear passage further divided into multiple sub-flow passages through branching. This hierarchical segmentation provides extensive coverage to multiple heat transfer tubes while maintaining uniform flow distribution through the linear geometry of each segment
Solution Approach 2:
Each linear flow passage is designed with uniform cross-sectional properties and consistent geometry along its length, ensuring that the local flow characteristics remain uniform. The branching flow passages are symmetrically arranged to maintain equal flow distribution to each sub-flow passage, thereby preserving uniformity while expanding coverage
Data Source
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AI summary
In a laminated header, second flow passages and fourth flow passages are configured in such a manner that refrigerant flowing through each of the second flow passages and the fourth flow passages flows in a direction opposite to a direction in which the refrigerant flows through each of a first flow passage, third flow passages, fifth flow passages, and sixth flow passages.