An exothermic reaction occurs in a 1000-gal reactor in which the temperature is maintained by cooling water in the jacket. The transfer function relating reactor temperature to cooling water is given by:
G(s) = 1.17e^-3s/10s+1
Each gallon of cooling water removes 167 Btu. The coolant control valve is a square root valve which delievers 50 GPM wide-open at a controller output of 15 psig and is fully closed at 3 psig controller output.
The steady state heat removal rate is 450,000 Btu/hr when the reactor is fully loaded. The controller is a PID, tuned by the Cohen - Coon procedure at the fully loaded operating condition.
A few days later the reactor throughput is reduced, with a corresponding reduction in the heat removal rate to 190,000 Btu/hr. The controller was not re-tuned.
What will happen to the process control and why?