Session: 13-01: OTEC, Applications and Devices

Submission Number: 182024

Transient Analysis of Oceanographic Variables Relevant to Ocean Thermal Energy Conversion in the Blue Amazon 

The energy transition and the future of the oil and gas industry are increasingly symbiotic. The frontiers of renewables have expanded rapidly and swiftly toward the future and, as a consequence, toward the ocean. The movement of a portion of the market is already occurring in the current cycle, and its curve will become more pronounced in the coming cycles. Oil companies have already begun a race to access representative renewable energy sources and also to use renewable products to enhance their operations, whether by increasing their scale of electricity generation, intermittent production, or in the short term, mitigating carbon emissions in their oil and gas extraction. Given the rapid maturation of the technology known internationally as Ocean Thermal Energy Conversion, together with oil and gas operators, with a focus on meeting their transition needs, high energy production rates, continuous operation (24/7), products of high economic interest, and their engineering variables are useful for offshore platform operations. Therefore, this proposal focuses on surveying the transient behaviors of a theoretical OTEC plant, regarding its variability in continuous electrical conversion and the oceanographic parameters that control the oscillations of its net power output. The overall objective of this work is to map the oscillations of the oceanographic parameters that control the theoretical OTEC plant in the numerical version, allowing the verification of the factors that would bring greater stability, enabling a higher degree of energy production reliability, 100% capacity factor, and a low level of oscillation in the net power available throughout the operating time. These behaviors, tested throughout the basins of interest in the Brazilian Blue Amazon, allow us to elucidate, with the adjustment of oceanographic variables from water masses of different densities and origins, the variations in conversion to electrical energy. The round of 5MW OTEC plants in the ocean domains of interest, using a Theoretical OTEC Numerical Model (MNTO), simulates the behavior of an OTEC plant, fed with oceanographic input data via global ocean model simulation rounds (HYCOM). The conversion of temperature differences into electrical energy via MNTO takes into account the physical and chemical properties of seawater, thermodynamic assumptions, the characteristics of the Rankine cycle, system losses, dimensions, depths of seawater intake pipes, [Cold Water Pipe (CWP) and Hot Water Pipe (HWP), and the outputs of the OTEC plant, in addition to the mass flows of both cases, their pump power, heat exchanger sizing, and finally their gross and net power, always on the time scale of the oceanographic data input that feeds the MNTO. To achieve the objective mentioned in the previous paragraph, we will map the behavior and variability of the MNTO's oceanographic input data, that is, the thermohaline properties (temperature and salinity) and pressure fields, in the domain of fields of interest within the Blue Amazon, as well as the wide range of input and output variables available. In the end, we can offer detailed maps of the variability of the net power obtained, establishing direct and indirect correlation relationships. Given the variability of MNTO input and output, the input parameters are adjusted in the chosen ocean domains so that the effects of the maximums, minimums, and differences of the variables of interest are able to smooth the transient behavior of the electrical energy produced in the analysis of the adopted scale.

Presenting Author: Roberto Valente de Souza LOC - Laboratório de Ondas e Correntes - COPPE - UFRJ

Presenting Author Biography: He holds a degree in Physics (2002-2007) from the Federal University of Rio Grande, a Bachelor's degree in Ocean and Atmospheric Physics (2010-2013), a Master's degree in Computational Modeling from the Federal University of Rio Grande (2012-2014) and a PhD in Physical, Chemical and Geological Oceanography from the Federal University of Rio Grande (2015-2019). He is currently a postdoctoral fellow at COPPE, the Alberto Luiz Coimbra Institute of Graduate Studies and Engineering Research, of the Federal University of Rio de Janeiro, applied in Naval and Oceanic Engineering, located at the Wave and Current Laboratory (LOC). He has experience in Physics, focusing on Ocean and Atmospheric Physics, computational languages, numerical modeling applied to fluid physics, geophysical energy cascades, and renewable marine energy. His main research area is Ocean Thermal Energy Conversion (OTEC), and he dedicated his Master's, Doctoral, and Postdoctoral studies to the application of this technology and its feasibility alternatives in the Brazilian Blue Amazon.

Authors:

Roberto Valente de Souza LOC - Laboratório de Ondas e Correntes - COPPE - UFRJ
Joel Sena Salles Junior Institute of Naval and Ocean Engineering - Federal University of Rio de Janeiro
Antonio Carlos Fernandes \affil*[1Federal University of Rio de Janeiro - Institute of Naval and Ocean Engineering
Daniel De Oliveria Costa Federal University of Rio de Janeiro - Institute of Naval and Ocean Engineering