OTEC performance tests of the Union Carbide sprayed-bundle evaporator

Technical Report · Tue May 01 04:00:00 EDT 1979

DOI:https://doi.org/10.2172/5926524· OSTI ID:5926524

Hillis, D L; Lorenz, J J; Yung, D T; Sather, N F

Results of performance tests on a Union Carbide sprayed-bundle evaporator with High Flux titanium tubes are reported. This unit performed satisfactorily and was free of operational problems. Under nominal operating conditions (3200 gpm water flow rate, 3.2 million Btu/hr heat duty, and 40 gpm ammonia feed rate), the overall heat transfer coefficient (U/sub 0/) was found to be 760 Btu/hr ft/sup 2/ /sup 0/F and the ammonia-side and water-side coefficients were 4600 and 1300 Btu/hr ft/sup 2/ /sup 0/F, respectively. The overall water-side pressure drop in the heat exchanger was 4.0 psi, and the vapor quality measured at various heat duties and ammonia feed rates was 99.2 +- 0.25%. Variations in heat duty (from 2.4 million to 4.0 million Btu/hr) and ammonia inlet temperature (from 52 to 72/sup 0/F) did not affect the value of U/sub 0/, nor did changes in ammonia feed rate in the range of 40 to 100 gpm. However, a minimum ammonia feed rate below which U/sub 0/ decreased sharply was observed; this corresponded to a local tube loading of 20 lb/hr ft and was essentially independent of heat duty. Finally contact between the liquid ammonia and the High Flux surface under nonboiling conditions appeared to deactivate nucleation sites, reducing U/sub 0/ to < 700 Btu/hr ft/sup 2/ /sup 0/F. The deactivated surface could be reactivated by drying out the tubes while maintaining warm water flow.

• Research Organization: Argonne National Lab., IL (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5926524
• Report Number(s): ANL/OTEC-PS-3
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140800* -- Solar Energy-- Ocean Energy Systems
AMMONIA
ELEMENTS
ENERGY TRANSFER
EVAPORATORS
FEEDWATER
FLOW RATE
HEAT TRANSFER
HYDRIDES
HYDROGEN COMPOUNDS
MEASURING INSTRUMENTS
METALS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
OCEAN THERMAL POWER PLANTS
OXYGEN COMPOUNDS
PERFORMANCE TESTING
POWER PLANTS
PRESSURE DROP
SEAWATER
SOLAR POWER PLANTS
TEST FACILITIES
TESTING
TITANIUM
TRANSITION ELEMENTS
TUBES
WATER