Exhaust Gas Heat Exchanger Pipe Joint for Remote Laser Welding
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Solution Overview
Problem
Existing heat exchangers for gases, particularly exhaust gases, face challenges in attaching tubular pipes using remote welding techniques due to spatial constraints and the need for strong, reliable welds, often requiring modifications that compromise structural strength and access issues.
Innovation Solution
A heat exchanger design featuring a tubular pipe with a radial projection that is laser-welded to the heat exchanger block, eliminating the need for butt joins and allowing remote attachment, with positioning means ensuring secure alignment and a larger contact area for enhanced welding accessibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If CMT welding is used to attach tubular pipes to the heat exchanger block, then strong weld joins are achieved, but the welding process requires approximately 20 seconds per join and substantial access space around the pipes
Solution Approach 1:
The tubular pipe is segmented by adding a separate projection (flange or collar) that extends radially from the pipe body. This projection is the specific portion that gets welded to the heat exchanger block, separating the welding function from the main pipe structure. This allows the welding operation to be performed on a dedicated attachment feature rather than the entire pipe, enabling faster remote welding processes while maintaining strong joins.
2Reliability
If CMT welding is used to attach tubular pipes, then reliable attachment is achieved, but substantial access space is required around the pipes for welding torch access
Solution Approach 1:
The projection extends radially outward from the tubular pipe in a direction perpendicular to the pipe's longitudinal axis, creating a new dimensional workspace for welding. This radial extension provides the welding torch with access from the side rather than requiring access along the pipe length, enabling remote welding positions and reducing spatial constraints in the original welding direction.
3Ease of operation
If remote laser welding is used to attach pipes, then welding can be performed remotely with minimal access space, but the weld joins are not as strong as desired
Solution Approach 1:
The projection is pre-formed on the tubular pipe before the welding operation. This preliminary structural preparation creates an optimized welding geometry that concentrates the welding energy and material deposition in a controlled manner, enabling remote laser welding processes to achieve sufficient penetration and strength without requiring complex multi-pass welding sequences.
4Ease of manufacture
If the pipe is inserted into the hole in the part or connector (as in prior art proposals), then attachment is achieved, but substantial modifications to the part are required that could affect structural strength
Solution Approach 1:
Instead of inserting the pipe into the heat exchanger block (inward attachment), the projection extends outward from the pipe and is welded to the outer surface of the block. This inverted attachment approach eliminates the need for large insertion holes through the block, preserving the structural integrity of the heat exchanger block while achieving reliable pipe attachment through external welding of the projection.
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 facilitates faster and stronger welds, reducing processing time and costs, while maintaining structural integrity and enabling easier integration into automatic welding processes, with welds that penetrate both the projection and the block for robust attachment.
Implementation Method 1
the at least one projection is joined to a region of one of said two opposing surfaces that surrounds said through-hole by laser welding, preferably remotely
Implementation Method 2
a first fluid circuit for the circulation of gases and a second fluid circuit for the circulation of a coolant fluid, in which the first and second fluid circuits are isolated fluidically from one another and arranged to effect a heat exchange between said gases and said coolant fluid
Data Source
Figure 1~2
Figure 3A~3B
AI summary
The exchanger includes: - a heat exchanger block (B) with: - a first circuit for the circulation of gases and a second circuit for the circulation of a coolant fluid that are arranged to effect a heat exchange between the gases and the coolant fluid, - a part (P) with a through-hole (h) arranged so that the gases or the coolant fluid flow therethrough, and - a tubular pipe (T) with a projection (F) that extends radially outwards from one end (Ta) thereof and that is joined to a region that surrounds the through-hole (h). The method includes the manufacture of the heat exchanger according to the present invention.