Combustions systems create NOx, how will this be managed?
• Micro turbines are recognized as clean burning systems, even relative to conventional gas turbine engines. Estimates of the additional NOx contributed by micro turbines, derived from product literature, indicate that the increase in NOx concentration if all tunnel air in a typical tunnel were combusted could be from around 25 mg/Nm3 without the turbines to around 30 mg/Nm3. • Conventional gas turbine engines will produce NOx in the burning process, and add to the NOx already in the tunnel air from the vehicle exhaust and drawn into the tunnel with the fresh air intake. Initial estimates from numerical modeling indicate that if all of the air in a typical tunnel was processed through conventional gas turbine engines, the concentration of NOx might increase from around 25 mg/Nm3 without turbines to around 47 mg/Nm3. • It is possible to fit conventional gas turbine engines with reburner technology which is designed to minimize NOx creation in the turbine and to eliminate some of the NOx
