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Show • • • • ID fan damper positions, Stock feeder speeds, and conditions around the turbine (e.g., condenser backpressure) performing tests around the air heater to measure air heater inleakage as well as to measure velocity and flow of flue gas at the air heater inlet and outlet determining the furnace exit temperatures using optical pyrometry measurements taken at the 7th elevation of the unit characterizing the bottom ash or slag, and flyash, with respect to unburned carbon obtaining airborne emissions data from the continuous emissions monitoring system (CEMS) for opacity, S02, and NOx Some 21 parametric tests were conducted under this program. Each test lasted 2.5 to 4.5 hrs. Tests included baselines (100 percent coal) plus variations in fuel blend. Other variables considered in developing the tests included load and base coal. While most tests were conducted at or about full load, some minimum load tests were conducted. Data analysis associated with the tests focused upon measuring the ability of the unit to achieve full capacity when cofiring and trifiring blends, by measuring the fuel input to the boiler as a percentage of the firing rate associated with MCR. Stability was measured by calculating the mean values for all parameters, calculating the standard deviation, and then expressing the standard deviation as a percentage of the mean as well as calculating the 95 percent confidence interval. Efficiency was calculated by developing heat and material balances about the boiler when firing different blends of fuel under varying conditions. Emissions were determined, in lb/hr, from the CEMS ~ and emissions were converted to Ib/l06 Btu using the heat balances. It is important to note that the tests conducted at ALF were parametric tests. Each test, lasting only 2.5 to 4.5 hrs, provided some insights into the potential benefits and issues associated with cofiring and trifiring alternate fuels. At the same time, the phenomena observed during the tests were not evaluated with long term test programs. Consequently significant uncertainty exists with regard to the precision of these measurements. The parametric tests were designed to identify potential outcomes associated with alternate fuels, rather than to provide precise measurements of the long term impacts of such programs. Given the parametric nature of the test program, the results are summarized in terms of fuel characteristics, combustion and boiler performance characteristics, and the formation of airborne emissions. 2.0 Characteristics of Fuels Burned at the Allen Fossil Plant The Allen Fossil Plant was originally designed to bum high sulfur interior province coal, mined in the Illinois and Western Kentucky coal fields. In 1995, the plant initiated a switch from interior province coals to Utah bituminous coal. At the same time the plant initiated the TDF program and the testing of sawdust as a supplementary fuel. 4 |
