Hydrodynamic analysis of an inverted catenary coldwater pipeline of A Lttd plant

Drinking water is a precious commodity with growing demand, motivating the researchers to explore innovative and cost effective measures to augment the available resources. Low Temperature Thermal Desalination (LTTD) is one among the ideas that utilizes the ocean thermal gradient for the production of freshwater. The cold water from deep sea is drawn and transported to the coast or to a floating platform to aid the conversion of surface seawater to fresh water. The behavior of this cold water pipeline in open waters is to be studied through analytical, numerical and experimental studies before actual field implementation. This paper presents the preliminary analysis of a flexible cold water pipe made up of High Density Polyethylene (HDPE) catering for an island based desalination plant. The water is drawn at a depth of 400 m and transferred to the shore. The site with coral reef demands an inverted catenary profiled pipeline to minimize damages and is connected to sump at the shallow end and a clump weight at the deep end. Preliminary hydrodynamic analysis of the cold water pipeline is carried out using OrcaFlex software under regular waves. Obtaining the effect of flexible pipeline under regular waves besides carrying out vortex induce vibration analysis and modal analysis forms the scope of this study. Variation of VonMises stresses, and effective tension at salient points (top end, middle and bottom end) are included.