An OTEC Pilot Plant Heat Engine

This paper summarizes the heat-engine system design for an ocean thermal energy conversion (OTEC) plant and its integration in the platform, and describes system components and their performance and construction requirements together with the computed overall cycle performance and operation. Ancillary equipment and platform arrangement and support requirements are discussed as to their effect on the platform design. The heat engine and platform design is based upon the JHU/Applied Physics Laboratory (APL) folded-tube, shell-less heat exchanger module concept as developed from analytical and experimental work previously reported. The heat engine design discussed is among the candidates for the construction of large commercial OTEC plantships. In the APL concept, the plantship will cruise (graze) the tropical oceans to utilize the maximum available ocean temperature difference. They will produce energy-intensive products such as ammonia, which can be synthesized from sea water and air and shipped to U.S. or foreign ports for use as fertilizer or as a hydrogen fuel carrier. The pilot plant design presented is for a 10–20-MW net output plant made up of 2.5-MW_e net heat exchanger modules manifolded to 5 MW_e net turbine-generator sets. In this approach, it is anticipated that all construction requirements, manifolding, cycle control, and installation and operational requirements can be determined and evaluated for the detailed design of large commercial vessels.