Dynamic Submarine Power Cable Bend Stiffener Water Cooling

The bend stiffener is divided into two functional zones: an upper non-cooled section for bending control and a lower cooled section for thermal management. The water cooling system is segmented to cool only the lower portion where the hot spot occurs, leaving the upper portion uncovered to maintain bending flexibility. This segmentation resolves the contradiction by allowing each zone to optimize its specific function without compromising the other.

Water cooling is applied locally to the lower part of the bend stiffener where the hot spot forms, while the upper part remains non-cooled to preserve bending control capabilities. The radial through-opening is positioned at a specific height to deliver water precisely to the hot spot region. This local quality approach allows the system to address thermal issues only where needed without compromising the mechanical flexibility required for bending control.

The cooling system extracts heat from the cable conductor through the water circulation path in the bend stiffener. By removing the hot spot caused by the bend stiffener's low thermal conductivity, the cable can operate at higher temperatures elsewhere, enabling reduced conductor cross-section for the same power rating. The extraction of heat in the critical region allows overall material reduction.

The temperature distribution along the cable is changed by introducing water cooling in the lower bend stiffener region. This parameter change (temperature reduction in specific zone) allows the conductor cross-section to be reduced while maintaining the same current carrying capacity, as the cooled region can sustain higher current density without exceeding maximum temperature limits.

The water cooling system utilizes natural convection and gravity-driven water flow through the bend stiffener, eliminating the need for external pumps or complex control systems. Water enters through the radial through-opening, cools the lower bend stiffener region, and exits through the water outlet. This self-service approach provides effective cooling while minimizing system complexity and avoiding additional active components.

Water acts as an intermediary cooling medium that transfers heat from the cable conductor to the surrounding environment. The water circulation path serves as a thermal bridge between the hot spot region and the cooler external environment. This intermediary approach provides efficient heat transfer without requiring direct thermal contact between the cable and complex cooling apparatus.