114.What are the reasons for high steam temperature at the primary super heater outlet? How to handle it?

The heat transfer in this zone is purely by convection. In this the steam flow and mass flow of flue gas shall be matched. If the flue gas mass is more than the steam flow, the steam temperature will increase. No attemperator is possible for this section. By properly adjusting the air flow for this low load will maintain the primary super heater steam temperature within limits. When the Automatic combustion is tuned, the fuel/air ratio shall take this into consideration in fixing the excess air.