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Show River Rouge Conclusions The SPO test successfully met Detroit Edison's objectives, providing a 20 to 30% improvement in NOx emissions and a 0.4 to 0.9% improvement in boiler performance. These gains were achieved without sacrifice of normal operating requirements. The knowledge obtained from this tuning demonstration will by used by Detroit Edison to evaluate and develop strategies to meet the CAAA Phase II requirements. Operating guidelines will be developed from the modeling information. Use of these guidelines will demonstrate whether the improvements achieved can be sustained over time. The model will be updated periodically with new data to maximize its accuracy and value. Attention will be given to what effects, if any, the new operating regimen has on corrosion and other long-term concerns. CASE 3 -ILLINOIS POWER'S HENNEPIN STATION Hennepin Background Illinois Power Company (IP) has three boilers that were affected by CAAA Phase I. As part of its compliance strategy, IP chose to installlow-NOx burners on only two of those boilers. The strategy employed for the third boiler, Hennepin Power Station Unit 2, was to reduce NOx emissions to a minimum level via tuning. In addition, it was important that the boiler be operated without a reduction in efficiency under the new operating regimen. IP, working with the EPRI, determined that these objectives were consistent with SPO and began a Tailored Collaboration project with EPRI7 • IP's goal was to achieve a boiler-tuning solution that would give equal emphasis to the dual objectives of compliance with emission regulations while securing cost savings and a rapid return on investment. The solution should also provide for continuous improvement and response to boiler system dynamics through an on-line operator advisory capability. Hennepin Unit 2 is a tangential, twin-furnace, controlled-circulation, coal-fired boiler rated at 235 MW. Figure 8, the Decision Diagram, shows the control parameters that were adjusted and the outputs that were to be improved or constrained to acceptable levels. Hennepin Improvements The initial optimization resulted in a reduction of NOx emissions at full load exceeding 20% from previously untuned baseline conditions. At the same time, boiler efficiency was increased from 89.3% to 91.5% in obtaining a lowest-cost balance to the operation of the boiler. These results were achieved with less than two weeks of effort. Figure 9 shows the run-by-run progress in reducing NOx and improving boiler efficiency using SPO. "Goal" is a function that was created to give equal weight to accomplishing both these objectives at the same time. For both the NOx and efficiency components of goal, lower is better. Operator AdviSOry System An additional task performed after initial optimization was assessment of the operational, functional and technical requirements for integrating an UL TRAMAX Workstation with the Hennepin Unit 2 Westinghouse WDPF Distributed Control System (DCS) as a continuous, on-line Operator Advisory System. 7 |
