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U.S. Department of Energy
Office of Scientific and Technical Information

Heat pipes for sodium-sulfur batteries. Final report, 29 August 1988-1 May 1989

Technical Report ·
OSTI ID:5194459
The objective of this program was to develop a variable-conductance heat pipe (VCHP) for the thermal management of sodium-sulfur batteries. The VCHP maintains the sodium-sulfur battery within a specified temperature rise limit (20 C) while the battery discharges a thermal load from 0 to 500 watts. A preliminary full-scale thermal-management design was developed for the sodium-sulfur battery, incorporating the VCHPs and supporting integration hardware. The feasibility of the VCHPs for this application was proved by test. The VCHP developed in Phase I utilized titanium as the heat-pipe envelope material, and cesium as the heat-pipe working fluid. The wick structure was axial grooves. Analysis and tests indicate that the VCHP can provide the passive thermal control necessary for the sodium-sulfur battery. Test data show that with the heat input from Q = 0 watts to Q = 500 watts, the VCHP evaporator temperature increased from 350 to 385 C. The temperature control range was higher than predicted due to working fluid vapor diffusion into the noncondensible gas and thermal axial conduction into the VCHP reservoir. Analysis has shown that by utilizing VCHPs for passive temperature control, the sodium-sulfur battery cells will have a lower axial delta-T during discharge than a current-louver design. The VCHP thermal management package has the potential to be used in geosynchronous earth orbits (GEO) and low earth orbits (LEO).
Research Organization:
Thermacore, Inc., Lancaster, PA (USA)
OSTI ID:
5194459
Report Number(s):
AD-A-212523/5/XAB
Country of Publication:
United States
Language:
English