skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Preliminary experimental studies with seawater on OTEC spout evaporator thermal effectiveness and phase transition in upcomer

Conference ·
OSTI ID:5748241

An experimental open-cycle ocean thermal energy conversion (OC-OTEC) test facility has been erected to perform spout evaporator experiments with seawater. The facility, located at Ke-ahole Point, Kona, Hawaii, consists of a spout evaporator, a spray condenser and an on-line deaerator. Warm seawater at 25-27/sup 0/C from 8 m depth and cold deep seawater at 7-10/sup 0/C from 580 m depth is available throughout the year to the facility. The results of thermal effectiveness tests are reported. The error due to instrumental uncertainties in thermal effectiveness measurements has been estimated to be of the order +-5.5 percent. The effect of design parameters; spout height, spout diameter and liquid loading on thermal effectiveness have been observed and compared with the existing theoretical predictions. A modified thermodynamic approach is proposed to evaluate average heat transfer characteristics of spout evaporators using a three component heat transfer coefficient approach. It adequately describes heat transfer characteristics of the spout evaporator under study. Results essentially agree with data obtained by others for fresh water, but clearly indicate the need for improvement of the existing model to take into account a number of identified factors associated with the real life OC-OTEC conditions, such as the transience in evaporator performance associated with the ocean-generated flow and pressure fluctuations and effects of noncondensable gases.

OSTI ID:
5748241
Report Number(s):
CONF-861211-
Resource Relation:
Conference: American Society of Mechanical Engineers winter meeting, Anaheim, CA, USA, 7 Dec 1986; Other Information: Technical Paper 86-WA/HT-34
Country of Publication:
United States
Language:
English