OCR Text |
Show TVA'S PROPOSED LABORATORY-SCALE COAL COMBUSTOR Earl G. Marcus, Robert L. Frank, Jr. Tennessee Valley Authority r _ J) (j /2^>, 1170 Chestnut Street Towers II Chattanooga, Tennessee 37401 y AT TW 1CIUI6BB66 v a n c j nuLUULi-LJ^ j | ^ - 501 Chemical Engineering Building Jj you^ O^^. Muscle Shoals, Alabama J. W. Barrier Tennessee Valley Authority ABSTRACT TVA operates^63jcoal-fired boilers ranging in size from 60 MW's (Watts Bar) to 1,300 MW's(Cumberland). The individual TVA power plants are designed to burn coals with ash contents ranging from 11.0 percent (Allen) to 21.0 percent (Paradise 1 and 2), and with sulfur contents ranging from 3.0 percent (Bull Run) to 5.0 percent (Paradise 1 and 2 and Widows Creek 8). Many of these plants are actually fired with a variety of coals from a large number of mines. The general types of coal fired by TVA plants range from V the high-sulfur, low-ash fusion temperature coals of western Kentucky and r ^y' > Illinois to the low-sulfur, high-ash fusion temperature coals of West /§ $6±/j~~ Virginia, eastern Kentucky, and eastern Tennessee. £cr*JD An improved method of evaluating specific coals to determine their suitability for use in specific boilers is needed. This paper describes the conceptual design of a proposed pulverized-coal laboratory-scale combustor for evaluating coals under a range of firing conditions to determine their slagging and fouling behavior, the ease of carbon burnout, emissions, and other items of interest. It is expected that coal samples can be evaluated by burning them under a range of standardized conditions, and that the slagging and fouling behavior exhibited in the laboratory furnace will be predictive of slagging and fouling behavior in a full-scale boiler. The conceptual design and cost of the test facility and its economic viability as a fossil plant improvement project are reported. The economic effect of reductions in the forced outage and equivalent forced outage (unit deratings) rates at TVA steam plants due to boiler slagging are investigated. Cost/benefit ratios and potential net savings associated with the project are reviewed. 4-1 |