Autocompression as a Method of Accumulating Waste Energy during the Emergence of an Autonomous Transport Module using a Change in Buoyancy

Abstract

Despite the Covid-19 pandemic lasting for few years, the interest in the exploitation of deposits lying at the bottom of seas and oceans at great depths has not been waning. Many new concepts for the exploitation of sea deposits have been developed. Many consortia were established, interested in mining activities in seas and oceans. And although the most advanced venture of Nautilus-Minerals has not been successful so far, it has made a huge leap forward in terms of research and technology. The exploitation on an industrial scale is most likely to start in the coming years, especially in the waters of the EEZ (Exclusive Economic Zone). Recently, for example, the Cook Islands authorities have granted three licenses for this type of activity. In international waters though, we must, unfortunately, still wait for legal solutions satisfying all interested parties. The exploitation of shelf deposits is successfully being carried out with various methods in many regions around the world (Karlic, 1984; Depowski et al., 1998; Abramowski, Kotliński, 2011; Niedoba 2015, SPC 2013; Sharma, 2017); however, reaching for deposits of massive polymetallic sulphides or polymetallic nodules lying at great depths places considerable demands on scientists and engineers. Among the heaviest ones is the development of a method of transporting spoil from the bottom to the sea surface. For several years, the authors have been conducting theoretical and experimental research on new concepts of transport from the seabed, the results of which were presented in numerous publications (Filipek W., Broda K .: 2016, 2017, 2018, 2019, Broda, Filipek, Tora 2023). While considering various concepts of transport from the seabed using an autonomous module, we paid attention to energy losses during the exchange of the working medium between the autonomous transport module and the surroundings (sea water). In the articles (Filipek W., Broda K. 2018, 2019) we focused on the positive aspect of this exchange, but nevertheless these are energy losses. In this publication, the authors analyze what part of this energy can be used (in autocompression) and what impact it has on the energy balance of the transport module.