A single β″-alumina tube AMTEC cell in which sodium working fluid is returned by a wick structure is designed, built and tested. The sodium which condenses in the low temperature condenser is transported to the high temperature evaporator through the wick, which generates the capillary force against the sodium vapor pressure using the fine porous structure of stainless-steel powder. Current-voltage characteristics were measured at an operating temperature of 923 K. The cell with TiN electrode achieves a specific power output of 0.13 W/cm2 initially. An electrochemical model is introduced to predict the cell performance and the calculated total resistance of the cell is 25% smaller than the measured one. The anode side current collecting resistance appears to increase the internal total resistance. Time dependent power output is also measured. Following an initial 15-30% decrease, the cell continues to generate power output in excess of 0.1 W/cm2 for a period of 100 hours. The result indicates that the designed wick can return liquid sodium against the pressure difference between the low pressure condenser and the high pressure evaporator in the cell.
ASJC Scopus subject areas
- Chemical Engineering(all)