A control system with the computer used on 35t/h fluidized bed utility boiler

A real-time closed loop control system using microcomputer, which has been used for the control of two 35t/h fluidized bed boilers in practice, is introduced in this paper. The overall control scheme, including eighteen loops i.e. level of steam drum, temperature of superheat steam, steam pressure, bed temperature, vacuum of combustion chamber, rest of fluidizing air and bed height, are presented. Its main features are that the boiler load is adjusted by the bed temperature associating with the bed height, while water supply and steam temperature adjustment are decoupled. The hardware and the software of the system as well as the anti-interference measures are introduced, and some plots of experimental results are also given. The techniques developed in the paper can be spread in the field of fluidized bed boiler, and also have application to other control systems.<
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