OCR Text |
Show Conclusions M P V systems offer a new tool for boiler diagnostic and optimization. It must be stipulated that although these systems are user-friendly, they reflect the complexity of combustion process, and the user must learn how to apply the new systems to his specific boiler/burner design and operating conditions. Therefore, a learning is required and a learning curve is involved. The user has to develop a boiler and burner adjustment strategy applicable to his particular boiler. The H C plant engineers applied significant efforts trying to learn the new M P V systems and to develop strategies of using them in efforts to enhance boiler performance. And while learning the new systems, they were actually learning their boilers, developing a better understanding of boiler design, operation, interactions and limitations. It became clear, for example, that the optimum strategies of using the M P V systems with B & W and F-W boilers were quite different. During the ozone season of 98, the main emphasis of boiler adjustment efforts at Homer City was reducing N O x . The main objective was to determine the lowest N O x level that could be achieved using the M P V systems. It was expected that LOI levels might even increase as a trade-off for N O x reduction. Long term boiler testing and adjustments conducted by plant engineers on all 3 units using the MPV-Plus system confirmed that the N O x level was essentially and consistently reduced. Daily plant records indicated consistent reduction of N O x by 10-20%. For example, the Unit 3 records indicated the average N O x level of 0.475 lbs/MMBtu during 5 days prior to M P V adjustments (in M a y 1998) vs average N O x level of 0.415 lbs/MMBtu during 5 days after the M P V adjustments (in August 1998). Further tests proved that the N O x level at HC-3 could be further reduced to 0.35 lbs/MMBtu (the initial target) and even down to 0.31 lbs/MMBtu (at 3.73%02). At the same time, the average LOI level was also reduced by 15-25 %. Similar results were achieved on Units 1 and 2. These numbers of N O x and LOI reduction produced significant actual savings due to increased boiler efficiency and N O x credits. Only in the course of summer months of 1998, the Homer City Station has accumulated almost $ 4 M in N O x credits. These impressive results proved the great potential capabilities and benefits of the new M P V systems. References 1. Khesin M.J. et al. "Combustion Control: New Environmental Dimension", American Power Conference, Chicago, 1993. 2. Khesin M.J. "Combustion Diagnostics based on Frequency Spectra Analysis", American Flame Research Committee, Monterey, C A , Oct. 1995. 3. Khesin M.J. "Signal Processing for Combustion Diagnostics", U S Patent No. 5,798,946. 4. Khesin M.J. et al. "Demonstration of N e w Frequency-Based Flame Monitoring System, American Power Conference", Chicago, April, 1996. 5. Khesin M.J. et al. "Application of a Flame Spectra Analyzer for Burner Balancing", ISA/EPRI Conference, Baltimore, June 1996. 6. Khesin M.J. et al. "Demonstration of N e w Flame Monitoring System at a Pilot-Scale Gas- Fired Combustion Test Facility", American Flame Research Committee, International Symposium, Baltimore, M d , September, 1996. 7. Khesin M.J. et al. "Demonstration Tests of N e w Burner Diagnostic System on a 700 M W Coal-Fired Utility Boiler", American Power Conference, Chicago, April 1997. 8. Khesin M.J. et al. "Application of a N e w Burner Diagnostic System for Coal-Fired Utility Boilers", ISA/EPRI Symposium, Knoxville, June 1997. 9. Khesin M.J. et al. "Continuous On-line Monitoring of Unburned Carbon. Case Study on a 650 M W Coal-Fired Unit", D O E FETC Conference on Unburned Carbon, Pittsburgh, May, 1998. 13 |