Stirred tank heater feedforward control

Figure 1.4 Feedforward temperature control for stirred tank heater.

The question that arises is How do we design feedforward controllers The reader may have suspected already that conventional P, PI, or PID controllers will not be appropriate. Let us start with an example, the design of feedforward controllers for a stirred tank heater. 

Figure 21.3 Block diagram for feedforward temperature control of a stirred tank heater (a) steady state (b) dynamic.

Figure 21.8 (a) Temperature response of a stirred tank heater under feedforward control alone, and with feedback trimming (b) corresponding block diagram. 

Consider the stirred tank heater shown in Figure 1.1. The control objective is to keep the temperature of the liquid in the tank at a desired value (set point) despite any changes in the temperature of the inlet stream. Figure 1.2 shows the conventional feedback loop, which measures the temperature in the tank and after comparing it with the desired value, increases or decreases the steam pressure, thus providing more or less heat into the liquid. A feedforward control system uses a differ-... 

V.21 Derive the nonlinear, steady-state feedforward control system that will keep the exit temperature of a stirred tank heater at the desired set point despite any changes in the inlet temperature or flow rate, T, and F,. The feedforward control system should be capable of (1) rejecting the effect of disturbance changes, and (2) tracking any set point changes. Identify all relevant transfer functions. 

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See also in sourсe #XX -- [ ]

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