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DOE OSTI · 1326856

OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

Varley, Robert·Halkyard, John·Johnson, Peter·Shi, Shan·Marinho, Thiago
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Abstract

A commercial floating 100-megawatt (MW) ocean thermal energy conversion (OTEC) power plant will require a cold water pipe (CWP) with a diameter of 10-meter (m) and length of up to 1,000 m. The mass of the cold water pipe, including entrained water, can exceed the mass of the platform supporting it. The offshore industry uses software-modeling tools to develop platform and riser (pipe) designs to survive the offshore environment. These tools are typically validated by scale model tests in facilities able to replicate real at-sea meteorological and ocean (metocean) conditions to provide the understanding and confidence to proceed to final design and full-scale fabrication. However, today’s offshore platforms (similar to and usually larger than those needed for OTEC applications) incorporate risers (or pipes) with diameters well under one meter. Secondly, the preferred construction method for large diameter OTEC CWPs is the use of composite materials, primarily a form of fiber-reinforced plastic (FRP). The use of these material results in relatively low pipe stiffness and large strains compared to steel construction. These factors suggest the need for further validation of offshore industry software tools. The purpose of this project was to validate the ability to model numerically the dynamic interaction between a large cold water-filled fiberglass pipe and a floating OTEC platform excited by metocean weather conditions using measurements from a scale model tested in an ocean basin test facility.

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13 HYDRO ENERGYCold Water PipeCoupled ResponseModel BasinOTEC

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Varley, Robert, Halkyard, John, Johnson, Peter, Shi, Shan, Marinho, Thiago. 2014-05-09. OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation. https://doi.org/10.2172/1326856

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