Helical Bend Stiffener for Flexible Risers Without Heat Trapping
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Solution Overview
Problem
Existing bend stiffeners for flexible pipes in offshore installations can cause overheating due to their thermal insulation properties, leading to potential damage from excessive temperature, and are often complex and costly to produce and install.
Innovation Solution
A helically shaped bend stiffener that surrounds a length section of the flexible pipe, with a root end locked to the end fitting, providing effective resistance against excessive bending while minimizing weight and reducing the risk of overheating through a simple and lightweight design that allows for easy installation and reduced material complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a traditional bend stiffener with thermal insulation properties is used, then the pipe is protected against overbending, but the pipe section covered by the bend stiffener overheats due to trapped heat
Solution Approach 1:
The patent removes the thermal insulation layer from the bend stiffener design, extracting the harmful thermal insulation property while retaining the mechanical bending protection function. This allows heat to dissipate naturally from the pipe surface without being trapped by insulating materials.
Solution Approach 2:
The patent converts the previously harmful effect of heat trapping into a beneficial situation by deliberately designing the bend stiffener to be thermally conductive or thermally neutral, allowing the natural heat dissipation to occur while still providing the necessary mechanical support against overbending.
2Reliability
If complex bend stiffener designs are used to provide comprehensive protection, then the protection effectiveness is improved, but the production cost and installation complexity increase
Solution Approach 1:
The patent divides the bend stiffener into functional segments: a core support structure that provides mechanical strength, and optional modular protective layers that can be added or removed based on specific application requirements. This segmentation allows for simplified base design while maintaining flexibility for enhanced protection when needed.
Solution Approach 2:
The patent applies protective features only where locally required rather than uniformly across the entire bend stiffener. For example, reinforcement is concentrated at high-stress zones, and thermal protection is applied only in areas prone to overheating, reducing overall material usage and complexity while maintaining effectiveness.
Data Source
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AI summary
An offshore installation comprising a riser pipe and a bend stiffener (12a, 12b). The riser pipe comprises a flexible pipe body (10) having a pipe length and an end fitting and the riser has a longitudinal pipe axis (A). The bend stiffener (12a, 12b) comprises a helically shaped body (12) arranged to surround a stiffened length section of the flexible pipe body (10). The bend stiffener has a root end (11a) and a far end (11b), wherein the root end (11a) is closer to the end fitting than the far end (11b) and the root end (11a) is locked at an axial distance to the end fitting, determined along the longitudinal pipe axis (A).