Study on Heat Dissipation and Cooling Optimization of the Junction Box of OBSEA Seafloor Observatory

Multidisciplinary underwater observatories represent an exceptional technological resource that can signify a qualitative forward step in marine scientific research as well as operational oceanography and climate change study. A cabled underwater observatory system that can provide broad bandwidth communication and power to oceanographic instruments is developed. The observatory consists of a subsea junction box that is fixed at a cable terminal, enabling real-time communication, power conversion, and power distribution of up to eight oceanographic instruments and one connection for a junction box. Therefore, the observatory has the capacity to cover a large range of distance-time observations, and to provide new opportunities for research and technological innovation. However, there are some issues to consider when designing the electronic system for the underwater observatory. The main concern is the location of the equipment in a hostile environment with difficult access for inspection and repair. Hence, appropriate heat management of the electronic apparatus has a significant influence on the useful life of this equipment. Specific validation and study of the behavior of the system prior the deployment, and permanent equipment status monitoring is essential to assure fault-free operation over the longest possible period of time. In this study, we present the thermal studies carried out on the junction box of the Observatorio Submarino Expandible Cableado (OBSEA) (expandable underwater cabled observatory) and the monitoring procedures are established. The underwater observatory has been deployed off the coast of the Balearic Sea and has been operating in real conditions for more than three years without interruption. The results show that this underwater observatory system is adequate for subsea real-time and long-term observations.