AN INVESTIGATION OF THE SENSITIVITY OF FLUIDIZED BED HEATERS CONTROL SYSTEMS
Fluidized bed heat exchangers are finding progressively wider applications because of their particularly low heat transfer resistance especially in the case of gases.
The present work deals with the dynamic analysis of closed loop control systems for fluidized bed heat exchangers under changing operating conditions.
The dynamic of the process are first derived. A single loop control structure is then considered. Alternative controller tuning methods are hence applied to this system in order to compute the controller settings for a set of design conditions. The closed loop performance under both servo and regulator conditions is hence generated assuming different operating temperature ranges and using the controller transfer functions obtained by different setting methods. The ability of the alternative tuning methods in producing controller transfer functions capable of producing a satisfactory performance when the operating conditions range is different from the set of nominal design conditions, has been thus assessed.
A sensitivity analysis of alternative control structures for fluidized bed control systems has been also conducted in this work. Four different control schemes are considered.