RJM CleanAir Burner™ retrofit to meet 30mg/Nm3 NOx

Key challenges

3 x 116MWth boilers require retrofit to meet NOx levels below 30mg/Nm³ as mandated by the new China Clean Air Act.

RJM Solution

Detailed site survey plus sophisticated CFD modelling, with a focus on diverting around 20% of the flue gases back through the burner to lower peak flame temperatures and thus reduce the formation of NOx. A new RJM Ultra-Low NOx CleanAir Burner™ was designed and combined with revised ducting for the FGR system plus a new, re-sized FGD fan.

Results

Boilers operating reliably and safely in automatic mode, across the entire boiler load range with NOx emissions at less than 30mg/Nm³ at 3.5% O₂ and CO emissions of less than 10mg/Nm³ at 3.5% O₂ with a measured boiler O₂ of 1%. With NOx emissions originally at 120mg/Nm³, this represents a substantial reduction of over 75%. In addition, because the new RJM burners can operate at less than 1% O₂, the plant is able to run more efficiently; typical competitor products cannot operate at less than 3% – 4% O₂ without impacting on combustion stability.