Pipe coupling structure and refrigeration cycle apparatus
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Solution Overview
Problem
Conventional pipe coupling structures in refrigeration cycle apparatuses face challenges in ensuring the strength of the coupling area between heat transfer tubes and pipes, particularly in smaller diameters, which can lead to defects and reduced durability.
Innovation Solution
A pipe coupling structure featuring a first refrigerant pipe with multiple expansion portions and a second refrigerant pipe with specific diameter configurations, allowing for easier insertion and brazing, while minimizing the brazed area to prevent defects and enhance durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the tube diameter of the heat transfer tube is reduced, then the heat transfer efficiency is improved, but the strength of the coupling area becomes insufficient
Solution Approach 1:
The coupling area is divided into multiple expansion portions (first expansion portion, second expansion portion, third expansion portion) with different expansion ratios. This segmentation allows each portion to contribute differently to the overall strength, enabling sufficient coupling strength even in small diameter tubes where the total coupling area is limited.
Solution Approach 2:
Different expansion ratios are applied at different locations along the coupling area. The first expansion portion has a first expansion ratio, the second expansion portion has a second expansion ratio different from the first, and the third expansion portion has a third expansion ratio different from the second. This local variation in expansion quality optimizes the strength distribution throughout the coupling area.
2Strength
If the brazed area is increased to improve coupling strength, then the strength is improved, but the risk of defects increases
Solution Approach 1:
The coupling area is segmented into multiple expansion portions with different expansion ratios, which distributes the brazing load across multiple zones. This segmentation reduces the concentration of stress and heat in any single area, thereby reducing the risk of brazing defects while maintaining overall coupling strength.
Solution Approach 2:
The expansion ratio parameter is varied across different portions of the coupling area. By changing the expansion ratio from the first expansion portion to the second and third portions, the brazing process can be optimized in each zone, reducing the likelihood of defects while achieving the required overall strength.
3Ease of manufacture
If the expansion ratio is uniform throughout the coupling area, then the manufacturing is simplified, but the strength distribution is suboptimal
Solution Approach 1:
Different expansion ratios are applied at different locations along the coupling area. The first expansion portion has a first expansion ratio, the second expansion portion has a second expansion ratio different from the first, and the third expansion portion has a third expansion ratio different from the second. This local variation in expansion quality optimizes the strength distribution throughout the coupling area.
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
The proposed structure improves the strength and durability of the coupling area, reduces the risk of defects, and facilitates easier assembly and brazing, while maintaining efficient heat transfer and reducing pressure loss.
Implementation Method 1
The fifth portion and the third portion are brazed
Data Source
AI summary
A heat transfer tube as a first refrigerant pipe has a first portion, a first expansion portion, a second portion, a second expansion portion, and a third portion arranged in order. A connecting tube as a second refrigerant pipe has a fourth portion facing the second portion and a fifth portion facing the third portion. The connecting tube is inserted into the heat transfer tube. The inner diameter of the second portion is larger than the inner diameter of the first portion, and the inner diameter of the third portion is larger than the inner diameter of the second portion. The outer diameter of the fifth portion is larger than the outer diameter of the fourth portion. The fifth portion and the third portion are brazed.