Testing,Identification,and Evaluation of Commercial and ''Advanced Experimental''Materials and Coatings under Design Conditions Simulating Fuel Power Cycle Combinations. Task II. Evaluation of Heat Exchanger Materials for Use in Coal-Fired Fluidized Bed Combustion Environment. Monthly Technical Progress Report No. 14.

摘要

The long-term combustor run was completed on July 10, 1977. During the July period,average bed temperature was 1610exp 0 F,superficial gas velocity was 7.4ft/s,while the SO sub 2content of the flue gas was 560ppM. During the 1500-hour run,specimen temperatures on the bed probe ranged from 1240to 1430exp 0 F,while the specimen temperatures on the freeboard probe were 1160to 1525exp 0 F. No gross deposit collected on the bed probe,but a pinkish-white deposit collected on the sides of the freeboard probe. Weight-loss measurements showed that alloys P9and IN671wasted linearly with time at high rates. The other alloys exhibited parabolic wastage with time. The data indicated that wastage rates for 310SS, 347SS, 18-18-2SS,and FSX 414would be 2to 3mils/year in the freeboard and 4to 6mils/year in the bed. The specimens exposed 500hours showed chromium depletion,except those specimens provided with a diffused aluminum coating. None of the alloys appeared to have been sulfidized. After 1100hours,the 316SS bed-cooling tubes were replaced because of severe leakage. The metal wastage on these tubes was found to vary with position in the bed,and perhaps with tube temperature. (ERA citation 02:055725)