Thermodynamic analysis of an OC-OTEC system in the direct-contact condenser configuration incorporating predeaeration and reinjection

The present study addresses the pertinent Open-Cycle Ocean Thermal Energy Conversion (OC-OTEC) noncondensable gas desorption rates and the subsequent effects this evolution of gases has on typical OC-OTEC system component thermodynamic performances. This study has determined that the OC-OTEC warm seawater resource can be expected to desorb approximately 70-80% of the available dissolved noncondensables under typical vertical spout evaporator temperatures and pressures. The cold seawater resource, under a coaxial direct-contact condenser configuration, can be expected to desorb approximately 90-100% of the dissolved noncondensables. These values were determined experimentally on a prototype scale 1.0+ MW OC-OTEC system (excluding the turbine system) under typical OC-OTEC seawater resource flow rates, temperatures and system pressures.;With this experimentally determined knowledge and the overall mass transfer rates for these noncondensables as determined by previous researchers, a thermodynamic evaluation and design was performed to determine the relative thermodynamic benefits associated with a 10 MW;Two hydraulic compressor configurations were investigated; a standard discharge pipe design and a tapering pipe design. It was found that a nominal savings of approximately 0.1% of the total gross power production could be recovered through the use of the tapering pipe design over the standard discharge pipe design.