BROADWATER Sugar Mill has installed a new high-pressure co-generation boiler that is
able to use a wide range of fuel to provide steam energy for both the generation of
electricity and processing sugar. The control limits for the steam conditions are very
tight being + 10o C at 510o C at 72 bar pressure. Due to the wide range of fuel types
burnt in the boiler, the control system has been modified to be able to cope with these
changes while still delivering a constant steam pressure and temperature output. This
paper discusses the introduction of an on line “calorific†calculator and its utilisation in
the advanced control of the boiler. It has been possible, after the introduction of the CV
corrector control loop, to change fuel from straight bagasse to straight woodchip in less
than 2 min while maintaining smooth, automatic operation of the boiler.