Dynamic behavior of water intake riser for ocean thermal energy conversion system

Abstract

Renewable energy has been regarded as an alternative to generate electricity. One of the examples for this energy is the Ocean Thermal Energy Conversion (OTEC) system which harnesses the temperature difference between sea surface and deeper ocean layer. Most research on OTEC is related to system efficiency but does not address the behavior of subsystem such as its water intake riser (WIR). Thus, this research aims to identify the dynamic behavior of water intake riser in terms of its vertical displacement and tension in order to investigate the sensitivity of key parameters of water intake riser design. The study covers the dynamic behavior of a derived mathematical model with reference to its vertical displacement and tension ratios result in which the length of the riser needs to be suitably designed particularly during the riser excitation period. A stiffer material of the riser has to be selected to obtain small vertical displacement and tension ratios while the diameter of the WIR only needs to be taken into account if the efficiency of the OTEC is of major concern. This study could aid in designing the suitable WIR to be implemented for the OTEC system.