Process Control: Modeling, Design, and Simulation

3.6. Integrating System

We found in the previous chapter that material balances on liquid surge vessels or gas drums often yielded models with the following form:

Equation 3.32

In the Laplace domain, this is

Equation 3.33

Consider an integrating process initially at steady state, with y(0) = 0.

Step Response

If a step input change of Δu is made at t = 0,

and we find the time-domain value

Equation 3.34

That is, the output ramps with a constant ...