Optimization of Powerhouse Operation at Champion International Inc., 1995 Process Control, Electrical & Information Conference Proceedings

R. Meyers, D. Standerfer,

E. Zychowski, G. Gover

Champion International

N. Ito, W.L.Bialkowski,

Engineering Inc.

The Champion International Inc. Quinnesec mill has experienced boiler instability problems since start-up, to the extent that boiler trips occurred as a result of boiler steam drum level swings. Steam demand changes of only 22.7 tonnes/hr (50,000 lbs/hr) were often sufficient to induce upsets large enough to cause boiler trips. Many attempts were made to correct this problem without success. The problem has now been resolved as a result of a recent project which involved: a thorough analysis of the dynamic behavior of the boilers, steam header, fuel system, equipment and instrumentation; the building of an accurate dynamic simulation model of the powerhouse; and Lambda tuning key control loops. The simulation model allowed both equipment sizing and control tuning changes to be assessed. The Lambda tuning methods used to tune the boiler steam drum level controls, accounted for the steam drum shrink/swell effects, and allowed the drum level controls to be both responsive and stable. Similar tuning was used to settle down the bark delivery system, the steam header controls and the boiler water conductivity control. As a result of the project, there have not been any boiler trips resulting from drum level upsets.