Preliminary Study of an Efficient OTEC Using a Thermal Cycle with Closed Thermodynamic Transformations

The research work is focused on thermal engine structures undergoing isobaric expansion-compression based thermal engines powered by ocean thermal energy. The isobaric expansion-compression based thermal cycles referred to in this paper, differs from the conventional quadrilateral Carnot based thermal cycles in that the conversion of heat to mechanical work is performed assuming a load reaction driven path function, where as heat is being absorbed (isobaric expansion process) and rejected (isobaric compression process), mechanical work is simultaneously performed without the conventional quasi-entropic expansion, contrary to what happens in conventional quadrilateral based Carnot engines.
An analysis of the ideal thermal cycle performed by means of an isobaric expansion-compression based cylinder is carried out and results compared with some previously achieved results of conventional technology including that of a Carnot cycle operating under the same ratio of temperatures. Into the range of its inherent low operating temperatures high ideal thermal efficiency is achieved for hydrogen and helium as working fluids. The achieved results associated with a simple and compact machine envisage the way towards a new generation of ocean thermal energy convertor (OTEC) power plants operating with the isobaric expansion-compression based cylinder.