Double-Pipe Combustor Structure for Thermal Expansion and Rotation Restraint
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Solution Overview
Problem
In CO2 gas turbine facilities, the thermal elongation difference between inner and outer pipes in a double-pipe structure causes instability and potential abrasion due to rotational forces, making it difficult to securely fix the inner pipe, which is critical for efficient power generation.
Innovation Solution
A double pipe configuration with a circumferential rotation prevention mechanism and axial movement restriction mechanism, including protruding parts and fitting grooves, prevents the inner pipe from rotating and moving axially, ensuring stable positioning and reducing abrasion risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the inner pipe is supported swingably to accommodate thermal elongation difference, then the pipe can handle thermal expansion, but the inner pipe may rotate due to rotational force causing abrasion
Solution Approach 1:
The patent applies preliminary anti-action by providing a rotation prevention mechanism that counteracts the rotational force before it can cause damage. The mechanism includes a rotation prevention member that engages with the inner pipe to prevent rotation in advance, while the swing support continues to accommodate thermal elongation. This resolves the contradiction by preemptively preventing the harmful rotation while maintaining the adaptability for thermal expansion.
2Reliability
If the inner pipe is fixed to the outer pipe, then rotational stability is improved, but thermal elongation difference causes stress and potential damage
Solution Approach 1:
The patent applies segmentation by dividing the support function into two independent parts: a swing support mechanism that handles thermal elongation accommodation, and a rotation prevention mechanism that handles rotational stability. The inner pipe is supported swingably by the swing support while a rotation prevention member prevents rotation. This segmentation allows each mechanism to perform its specific function without causing stress to the pipe structure.
3Adaptability or versatility
If the inner pipe extends further than the outer pipe to accommodate thermal elongation, then thermal expansion is managed, but the swing portion undergoes abrasion
Solution Approach 1:
The patent applies preliminary anti-action by preventing the rotation that causes abrasion before it occurs. The rotation prevention member is positioned to engage with the inner pipe and prevent rotational movement that would otherwise cause the swing portion to undergo abrasion during thermal elongation accommodation. This resolves the contradiction by preemptively eliminating the harmful rotational motion while maintaining the necessary thermal expansion capability.
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 configuration effectively prevents the inner pipe from rotating and moving excessively, reducing the risk of abrasion and maintaining structural integrity, thereby enhancing the operational stability and efficiency of the gas turbine combustor system.
Implementation Method 1
the inner pipe sometimes undergoes rotational force in the circumferential direction, which centers the center axis of the double pipe, due to the low-temperature carbon dioxide supplied to the annular passage between the inner pipe and the outer pipe
Implementation Method 2
This causes the inner pipe to extend further in a center axis direction of the double pipe than the outer pipe, and therefore, a thermal elongation difference occurs between the inner pipe and the outer pipe
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A double pipe 60A of an embodiment includes: an outer pipe 70; an inner pipe 80 inserted through an interior of the outer pipe 70 to make high-temperature carbon dioxide flow therethrough; and an opening 72 of the outer pipe 70 which introduces low-temperature carbon dioxide to an annular passage 61 between the outer pipe 70 and the inner pipe 80. The double pipe 60A further includes: an inner pipe protruding part 91 protruding from an outer peripheral surface of the inner pipe 80 to a radial outside; and an outer pipe protruding part 92 protruding from an inner peripheral surface of the outer pipe 70 to a radial inside, the outer pipe protruding part 92 having a fitting groove 93 fitted to the inner pipe protruding part 91 and penetrating in an axial direction.