Refrigerant pipe
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Solution Overview
Problem
The existing method of joining stainless steel and copper tubes using furnace brazing results in strength deterioration of the copper tube at high temperatures, leading to potential deformation during transportation and assembly of refrigerant pipes.
Innovation Solution
A refrigerant pipe design featuring a stainless steel pipe body and a copper or copper alloy connecting tube, where the connecting tube is overlapped and brazed with a lower melting point filler material to prevent strength loss, and a protrusion on the pipe body ensures reliable connection and compensation for strength deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If furnace brazing is used to join stainless steel tube and copper tube, then the tubes can be connected, but the copper tube experiences strength deterioration in high-temperature furnace environment
Solution Approach 1:
The invention changes the brazing temperature parameter from high temperature (furnace brazing) to low temperature (below 450°C), thereby preserving the strength of the copper tube while still achieving reliable joining. This parameter change resolves the contradiction by allowing easy manufacture through brazing without suffering from high-temperature strength deterioration.
2Ease of manufacture
If copper tube is used for connecting, then ease of joining is improved, but strength deterioration occurs at high temperature during furnace brazing
Solution Approach 1:
By changing the brazing temperature to below 450°C, the invention maintains connection reliability through proper brazing while avoiding the high-temperature strength deterioration of copper. The low-temperature brazing process ensures reliable joining without compromising the copper tube's mechanical properties.
3Productivity
If high-temperature furnace brazing is applied, then joining efficiency is improved, but deformation risk during handling increases due to strength loss
Solution Approach 1:
The invention adopts low-temperature brazing (below 450°C) which maintains tube strength while still providing efficient joining. The reduced temperature prevents strength deterioration and deformation risk during subsequent handling and assembly, resolving the contradiction between joining efficiency and strength preservation.
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 design enhances the strength and durability of the refrigerant pipe by preventing strength loss in the copper tube at high temperatures, ensuring reliable connection and reducing the risk of deformation during handling and assembly.
Implementation Method 1
the pipe body and the connecting tube are brazed with use of a brazing filler material having a melting point of below 450°C
Data Source
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AI summary
The invention provides a refrigerant pipe constituting a refrigerant circuit of a refrigeration apparatus, the refrigerant pipe including: a pipe body (21) made of stainless steel; and a connecting tube (22) made of copper or a copper alloy and provided to connect a different refrigerant pipe (23); wherein the connecting tube (22) is connected to an outer circumferential surface of an end in a pipe axis direction of the pipe body (21), and the connecting tube (22) has an entirety in the pipe axis direction overlapped with the pipe body (21) in a pipe diameter direction.