Heat Exchanger Head Welding for Thick-Wall I-Seam Joints
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Solution Overview
Problem
The existing heat exchanger manufacturing processes, particularly for thick-walled components, are labor-intensive and costly due to the need for complex weld seam preparations and multiple layers of welding, which can lead to material waste, long processing times, and high costs, especially when using submerged arc welding for high-pressure and high-thermal-cycling applications.
Innovation Solution
The use of electron beam welding, combined with other processes like submerged arc welding, to create high-quality I-seam welds that reduce material requirements, minimize heat-affected zones, and allow for precise, fast production, with a root back weld supporting the electron beam welding process, enabling efficient connection of thick components with larger tolerance fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional submerged arc welding is used for thick-walled components, then weld quality can be maintained, but manufacturing time and costs increase significantly
Solution Approach 1:
The patent combines two welding processes (submerged arc welding and electron beam welding) into a hybrid manufacturing approach. The submerged arc welding creates a root counter-weld that prepares the joint, while electron beam welding completes the fusion. This merging allows thick-walled components to be welded with fewer passes and reduced manufacturing time while maintaining high weld quality and reliability.
2Reliability
If complex weld preparations are made for high-pressure applications, then media tightness is ensured, but device complexity and manufacturing effort increase
Solution Approach 1:
The patent replaces extensive mechanical weld preparation (complex grooves, multiple passes) with a combination of automated welding processes. The submerged arc welding process automatically creates the root counter-weld, and electron beam welding automatically fuses the components. This substitution reduces the need for manual weld preparation while ensuring media tightness through consistent, high-quality automated welding.
3Strength
If multiple weld passes are applied to thick components, then complete welding is achieved, but heat input and thermal stresses increase
Solution Approach 1:
The patent achieves continuous welding action by combining two processes that together complete the weld in fewer steps. The submerged arc welding continuously builds the root counter-weld, and electron beam welding continuously fuses the remaining joint. This continuous action reduces the number of intermittent passes, thereby reducing cumulative heat input and thermal stresses while achieving complete welding penetration.
4Reliability
If difficult-to-weld materials like nickel-molybdenum alloys are used, then corrosion resistance is improved, but welding difficulty and costs increase
Solution Approach 1:
The patent changes the welding parameters by using electron beam welding, which operates under vacuum and allows precise control of energy input. This parameter change enables the welding of difficult-to-weld nickel-molybdenum alloys without excessive heat input, preventing microcrack formation while achieving complete fusion. The process transforms an otherwise intractable welding problem into a manageable operation.
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 approach significantly reduces manufacturing time and costs by minimizing material usage and heat input, ensuring high-quality welds with reduced thermal stresses and oxidation, allowing for efficient production of heat exchanger elements with wall thicknesses up to 200 mm, and enabling the use of difficult-to-weld materials like nickel alloys.
Implementation Method 1
The weld joint is welded by an electron beam
Implementation Method 2
in the area of the weld root, which is supported by a root counter-weld, a weld joint is formed by an electron beam
Data Source
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AI summary
The invention relates to a heat-exchanger element for connection to tubes of a heat exchanger, the heat-exchanger element (1, 29, 32) consisting of a plurality of components (13, 14) welded to each other, and said components (13, 14) being interconnected by electron beam welding and being part of a heat exchanger head.