Question:
A single capacity process tank is to be analyzed using proportional and integral PI and PD controllers. A single process tank could be a steam jacketed kettle as shown in Figure. Water is heated continuously by the steam flow and it is proposed to use a controller to regulate the steam flow. The steam flow is essentially depending upon to the valve opening which is controlled by TC. The temperature of the water in the kettle is measured using a RTD sensor and transmitted to the controller.
Analysis & Design aspect:
1. Assume appropriate time constants and other design parameters.
2. Study the possible step response of the system with proportional(P), and integral(1) controllers.
3. Evaluate the stability using Rouths Hurwartz criterion and obtain the range of K value for the stability under various controllers.
4. Evaluate the relative stability of the system with P and I controllers.