Studie samt reglering av luft- och massflöde för en barkpanna

Sammanfattning: This report treats two assignments that concerns the biofuel furnace at Billerud Skärblacka AB and how these assignments were solved. The assignments were: reducing the number of CO-spikes and tuning the overfire air control loop. To reduce the number of CO-spikes the possibility that skewness in mass distribution affects the number of CO-spikes were study. The skewnwss of mass distribution was controled and adjusted with two experiments. The conclusion that was made is that the skewness of mass distribution were not sufficient enough to affect the number of CO-spikes. Most likely because there are other factor that affects the number of CO-spikes more than the skewness of mass distribution. The objective with tuning the overfire air control loop was to find a faster and better interplayed control loop. To solve the assignment the first thought was to make a model of the furnace. But this idea was too much work for a single master thesis. Therefore a Simulink-model and a control strategy were produced instead. During the work with tuning the overfire air control loop the changes were issued from the control strategy and the Simulink-model were used for the tuning of the air valves. The result from tuning the overfire air control loop were faster regulators and a better tracking of the reference value for the secondary and tertiary air valve along with a reduced levels of carbon monoxide.