Heat Exchanger Header Structure for Secure Tube Insertion
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Solution Overview
Problem
Existing heat exchangers face challenges in maintaining the proper insertion length of heat transfer tubes, leading to potential extraction during assembly, which complicates the assembly process and can result in pressure loss and blockage of refrigerant flow paths.
Innovation Solution
The heat exchanger design incorporates a header with a tubular shape, featuring a base portion and protruding portions that provide an appropriate insertion length for heat transfer tubes, preventing extraction by ensuring the tubes are securely fixed during brazing, and includes a communication hole for uniform insertion and reduced pressure loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insertion length of heat transfer tubes is not appropriately provided, then the heat transfer tube may become extracted from the header during assembly, but providing a longer insertion length increases the complexity of the header structure
Solution Approach 1:
The header is divided into multiple members (first member, second member, third member) that are joined together. The first member includes protruding portions that segment the insertion space for multiple heat transfer tubes, providing individual insertion length control for each tube while maintaining a modular header structure.
Solution Approach 2:
The protruding portions of the first member are pre-formed to extend into the insertion space before assembly. These protruding portions preliminarily define the insertion length and positioning for heat transfer tubes, ensuring proper insertion depth is achieved before the tubes are permanently fixed during brazing.
2Manufacturing precision
If the heat transfer tube insertion length is insufficient, then extraction during brazing may occur, but increasing insertion length requires additional header members
Solution Approach 1:
The first member is designed with localized protruding portions that specifically address the insertion length requirement at critical locations. Rather than uniformly increasing the length of all header members, the protruding portions provide localized extension into the insertion space, precisely controlling insertion depth where needed while keeping other parts of the header compact.
Solution Approach 2:
Instead of extending the insertion length by adding more members in the longitudinal direction, the first member protrudes laterally into the insertion space. This dimensional approach allows the protruding portions to extend toward the heat transfer tubes from the side, providing precise insertion length control without increasing the overall longitudinal length of the header assembly.
3Ease of operation
If heat transfer tubes are loosely inserted, then assembly is easier, but pressure loss and blockage of refrigerant flow paths occur
Solution Approach 1:
The protruding portions of the first member automatically provide insertion guidance and positioning for the heat transfer tubes during assembly. The tubes self-align with the protruding portions, which maintain the correct insertion depth and positioning without requiring complex external fixtures or tools, thus keeping assembly simple while ensuring proper insertion.
Solution Approach 2:
The mechanical positioning function is substituted from a complex multi-component positioning system to a simpler protruding portion structure. The protruding portions mechanically define the insertion depth and alignment through their geometry alone, replacing the need for elaborate mechanical positioning mechanisms while ensuring consistent, precise insertion that prevents pressure loss.
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 enhances the ease of assembly, prevents tube extraction, reduces pressure loss, and ensures reliable refrigerant flow by maintaining the appropriate insertion length and preventing brazing material from blocking the flow paths.
Implementation Method 1
when the members are fixed to each other by brazing, extraction of the heat transfer tube from the header after finishing the brazing step is prevented
Implementation Method 2
a plurality of heat transfer tubes that extend in a direction crossing the longitudinal direction of the header and that are connected to the header
Data Source
AI summary
A heat exchanger includes: a header that extends in a first direction; and a plurality of heat transfer tubes that extend in a second direction crossing the first direction, each of which has one end connected to the header, and that are arranged in the first direction at intervals. The header includes: a header body having a tubular shape, a first member through which the one end of each of the heat transfer tubes extends, and a second member positioned between the header body and the first member in the second direction. The second member includes: a base portion that extends in the first direction, and a plurality of protruding portions that extend from the base portion toward the first member in the second direction.