Energy & Power Generation Consulting,
Engineering & Management Services



PROJECT: Refurbishment of Large Boiler Pneumatic Combustion Controls

Southern Cal Edison sold most of their traditional fossil fueled power generation facilities in approximately 1998 to several independent power producers (IPP's). Two 1950's vintage units were scheduled to be retired because recent air pollution environmental compliance requirements made it cost prohibive to invest advance technologies (e.g., SCR) to reduce NOx production. But, California was in the middle of an energy shortage and the Independent System Operator (ISO) needed these two unit's generation capacity of 172 net MW each. Therefore, the ISO granted the IPP funding to conduct maintenance activities and scaled down burner air flow modification to lower NOx production.

These two units were built in 1953, came with balanced draft B&W radiant type, single steam drum, bent tube boilers. Each boiler was rated at 1,140,000 lb/hr superheated steam at 1,990 psig and 1000/1000F superheat/reheat temperatures. The units have since been decommissioned and torn down for space to build gas turbines.

Services provided included providing the process evaluation for the draft and combustion systems and to manage the refurbishment of all the Bailey pnuematic controls. Both of the units had exceeded the capacities of the induced draft fans to maintain the boiler draft setpoint and thus had been curtailed in load up to 21 MW's. Success was achieved at finding and managing the corrections to the draft system to restore full generation capacity for both units. The restoration engineering and management services successfully returned both units to full automatic control, meet CA load demands, and attain Nox reductions exceeding expectations while still maintaining CO levels well within compliance limits.

A detailed engineering article describing the success of this project appeared in the August, 2002, Power Engineering magazine.