San Miguel Electric Cooperative Unit 1

Location: Jourdanton, Texas

Client: San Miguel Electric Cooperative

Completion Date: 2004

Burns & McDonnell supported San Miguel’s efforts with a NOx emission reduction project at San Miguel Unit 1, near Christine, Texas. San Miguel Unit 1 is a mine mouth 442-MW opposed wall-fired boiler firing Texas lignite.

  • Low NOx burner design and procurement
  • Multiple contract development, bid evaluations
  • Contract administration
  • Combustion air, FD fan, air heater evaluations
  • NOx compliance strategy evaluation
  • Windbox modeling and design modifications
  • Mill performance testing
  • Combustion tuning

San Miguel Electric Cooperative (SMEC) initiated a combustion improvement project to look at options to comply with Texas environmental restrictions. Burns & McDonnell was retained to evaluate options and implement a phased approach to solve the problem within the existing utility outage schedule.

After an evaluation of alternatives, a parallel path effort was begun to install new burners and overfire air along with evaluating SNCR application on the unit. The main goal of the project was to improve combustion and operation of the boiler as well as achieve NOx performance that met the new Texas regulations. The original SMEC burners were no longer adjustable after years of operation coupled with the lignite fuel, combustion optimization was challenging.

Overall operation investigations led the project team into several areas on the unit that needed attention including the FD fan preheat coils, windbox air flow distribution system as well as diagnostic equipment for preventing excessive slag formations.

Burns & McDonnell’s scope included all engineering, procurement, support of field installation contractor, startup and combustion optimization services. Project results include improved flame stability, better understanding of critical operating parameters on this unique fuel along with low cost NOx reduction.

  • Computational fluid dynamic modeling
  • Replacement burners designed for implementation with existing OFA system
  • Overfire air system
  • Combustion optimization
  • SNCR mapping, modeling and testing