Apparatus for Open-Cycle OTEC Heat and Mass Transfer Experiments at the Seacoast Test Facility

Abstract

Recently, the open-cycle OTEC system has been a focal research area for the U.S. OTEC program. Simultaneous production of electric power and desalinated water using OTEC plants has a potential for near-term commercialization. Desalinated water is produced when a surface condenser is used in the open-cycle or hybrid-cycle OTEC plant. To date, no seawater experiments have been carried out for flash evaporation and passive deaeration in a prototypical configuration. Furthermore, data are lacking for surface-condenser design and the effects of noncondensable gases. A reliable system-integration study cannot be carried out, or the potential of open-cycle and hybrid-cycle OTEC plants be evaluated, until seawater experiments are performed using a prototypical apparatus. This paper discusses experimental research for the open-cycle heat- and mass-transfer program. The apparatus will be designed for existing seawater capabilities of 1600 gpm (103 kg/s) warm-water and 1000 gpm (65 kg/s) cold-water flow rates. It will be possible to test components in the range of 0.5 to 1 MWt heat capacity. Initial experiments will include performance testing of single- and three-vertical-spout configurations, deaeration studies, and scoping tests for a surface condenser using an existing heat exchanger. Later, a prototypical surface condenser will be designed and tested in this apparatus. The paper describes salient features of the apparatus and instrumentation for conducting seawater experiments for the open-cycle system.