Valmet's Advanced Process Control (APC) application, Valmet DNA FBB Combustion Manager, has improved combustion for the biomass boiler at WestRock's Covington mill in Virginia, USA.
By optimizing combustion, the mill has been able to maximize and increase the main steam output of the biomass boiler beyond the maximum continuous rating (MCR).
Other benefits include more stable and controlled boiler steam output as well as improved operational uniformity across shifts, furnace symmetry and spray valve control. Valmet's APC application estimates the British thermal units (BTU) of the biomass fuel in real time and ensures a consistent optimum fuel power-to-air ratio.
The application has lowered the average O2 by about 0.3 percentage points, which improves boiler efficiency, reduces NOXemissions and subsequently minimizes NH3 consumption. Additionally, Valmet's advanced load controller now properly allocates the fuel demand between the feeders, taking into account any control and/or mechanical process limitations.
Valmet DNA FBB Combustion Manager is an advanced control application for the optimized combustion of both bubbling and circulating fluidized bed boilers. The purpose of the application is to protect the combustion process against variations in production, fuel amount, fuel quality and combustion circumstances.