| OCR Text |
Show from the HPS™ burner flame, causing it to read a higher temperature. If this was the case, the actual temperatures inside the firebox may have been comparable. In response to the difference in stack thermocouple readings, the advanced burner was tested at two different furnace configurations. The first configuration was with the furnace insulated, which produced firebox temperatures from 1,950 to 2,050oP. This condition represents the worst case scenario for NOx emissions, due to the likelihood for increased thermal NOx production. Tests 1 through 4 were performed with the furnace insulated. The other configuration was to test with the insulation removed. This lowered the firebox temperature to temperatures varying from 1,250 to 1,5()()OP depending on the overall heat input to the burner. The uninsulated firebox represented the worst case scenario for DRE, due to the relatively cool temperatures at the wall caused by the presence of the water jacket. The overall cooler firebox temperatures also acted to limit the DRE for this furnace configuration. In addition to the variations in firebox temperature, there were also some differences in the air preheat temperature for the tests. However, the variations among the ambient temperatures and preheat temperatures did not exceed 50oP, and therefore had a minimal impact on the rate of NOx formation. The advanced burner was tested on both No.2 and No.6 fuel oil. The No.2 fuel oil has an average fuel-bound nitrogen content of 0.02 percent. The No.6 fuel oil was measured to have approximately 0.24 percent nitrogen by weight. Since the burner was designed to operate on high-nitrogen content fuels, the No.6 fuel oil tests were considered to be more representative of a typical application. Therefore, this discussion will focus on the No.6 fuel oil results. Tests 1, 3, 5, and 6 on the advanced burner may be used for comparison with baseline test 3. Tests 1 and 3 demonstrate the performance of the advanced burner firing natural gas and No. 6 fuel oil with ambient combustion air. These tests were conducted in the insulated furnace, 10 |
