OCR Text |
Show 9 Key Elements of a NOx Tuning or Optimization Test Program The recommended key elements of a NOx tuning or optimization test program are outlined below: • Combustion diagnostics pulverizer performance improvement combustion controls diagnostics air register/damper adjustment ash carbon diagnostics • NOx emissions characterization parametric variation of boiler operating parameters • NOx tuning and optimization fine tuning of combustion uniformity over the load range definition of O2, ash carbon, and burner tilt and/or OFA tradeoffs (if appropriate) Based on the experiences outlined in the first half of the paper, diagnostic testing is recommended as a key initial element of any NOx field test program. At this point, it is appropriate to summarize some of the recommended diagnostic techniques that should be considered to address the problems illustrated previously. These recommendations are listed below: Recommended Diagnostic Techniques Problem Technique Furnace In-Leakage O2 Measurements from Furnace Exit to O2 Analyzer Location Non-Representative O2 Readings Recalibrate, Inspect Rlters, Add More Analyzers Non-Uniform FueUAir Distribution POint-by-Point Gaseous Emissions Traverse Burner Pipe Coal Loading and Primary Air Distribution Air Heater Leakage Test Combustion Controls Performance Reprogram Excess Air Controller and Reduce Deadband Design-Specific Factors Characterize O2 Uniformity with Burner Tilt, Load, OFA Flow and Windbox Pressure Off-Design Equipment Performance Review Sootblowing Practices, Boiler Heat Absorption Data, Boiler Performance Monitor Data |