Dynamic modelling of an Organic Rankine Cycle applied to electricity production by the mean of Ocean Thermal Energy Conversion (OTEC)
Résumé
Ocean Thermal Energy Conversion (OTEC) consists in using the temperature difference between hot surface seawater and cold deep seawater as an energy resource. This latter is often considered to be used as a stable base mean for electricity production. This study presents a dynamic model of an Organic Rankine Cycle (ORC) applied to OTEC, by using a Moving Boundary Model (MBM) for heat exchangers. This model consists in dividing the evaporator into three variant size parts (heating, evaporation and overheating) as well as the condenser (desuperheating, condensation and subcooling). Temperature variations in both working fluid and seawater side were computed. The response of the system following a step change in working fluid mass flow rate is then studied by considering input parameters from an OTEC onshore prototype located in Reunion Island. The output power of the system is then decreasing from 15.7 kW to 13.7 kW in a time lower than two minutes, after a decrease in working fluid mass flow rate by 25 %. This results show that the power of an OTEC power plant can be modulated with relatively short response times and it is therefore possible to consider using OTEC not only as a base resource, but also as a way to regulate the network in critical periods, particularly for non-connected grids.
Origine | Fichiers produits par l'(les) auteur(s) |
---|
Loading...