Multi-Member Header Brazing Design for Heat Exchanger Assembly
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Solution Overview
Problem
Existing heat exchangers face issues with defective brazing due to uneven melting of brazing filler materials, particularly those farther from the heat source, leading to inadequate joining of header components.
Innovation Solution
A heat exchanger design where the brazing layer between the second and third members has a higher melt rate than the layers between the first and second, and first and third members, with increased silicon content in the brazing layer between the second and third members, ensuring effective brazing even when the latter receives less heat, and a configuration that allows for efficient insertion and alignment of heat transfer tubes with reduced friction and minimal blockage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If brazing is performed on a header constituted by multiple laminated members, then the header can be assembled from separate components, but the brazing filler material far from the heat source is less likely to melt, causing defective brazing
Solution Approach 1:
The patent applies local quality by providing different silicon content specifications for brazing layers at different positions. Specifically, the brazing layer between the second and third members (which are farther from the heat source) has a higher silicon content (5-12 wt%) compared to other brazing layers. This localized compositional variation ensures that the brazing filler material at positions receiving less heat has enhanced melting capability, thereby achieving reliable brazing throughout the entire header assembly.
2Temperature
If the brazing layer between the second and third members has higher silicon content, then the melt rate increases at lower temperatures, but the composition control becomes more complex
Solution Approach 1:
The patent applies parameter changes by modifying the silicon content parameter of the brazing filler material based on position. The brazing layer between the second and third members contains 5-12 wt% silicon, while other brazing layers have different silicon content ranges. This parameter variation allows the brazing process to achieve appropriate melt rates at the actual temperature distribution encountered during brazing, ensuring reliable joining without requiring complex real-time control systems.
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 achieves an excellent joining state of brazing between components, even when the brazing layer between the second and third members is lower in temperature, and reduces pressure loss by minimizing unnecessary spaces around the heat transfer tubes, enhancing the overall strength and efficiency of the heat exchanger.
Implementation Method 1
a brazing layer between the second member (72) and the third member (73) has a melt rate, at a predetermined temperature, being larger than a melt rate, at the predetermined temperature, of at least one of a brazing layer between the first member (71) and the second member (72) and a brazing layer between the first member (71) and the third member (73)
Implementation Method 2
When the plurality of members mentioned above is joined by brazing
Data Source
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AI summary
The invention provides a heat exchanger configured to inhibit defective brazing of a header constituted by a plurality of members, a heat pump device, and a method of manufacturing the heat exchanger. An outdoor heat exchanger (11) includes a gas header (70) and a plurality of flat tubes (28) connected to the gas header (70), the gas header (70) has a plurality of members including a first member (71), a second member (72), and a third member (73) to be brazed to each other, the second member (72) and the third member (73) interpose a clad layer (C3) having a melt rate at predetermined temperature being larger than a melt rate at the predetermined temperature of at least one of a clad layer (C2) between the first member (71) and the second member (72) and a clad layer (C2) between the first member (71) and the third member (73).