Room Temperature sensor L Steam v D 5 L v Blower Heat

Chapter , Problem 12.19

(choose chapter or problem)

Hot-air heating control systems for large buildings may involve significant dead time if there is a large distance between the furnace and the room being

                                                     

heated (Figure P12.19). Proportional control applied to the specific plant

                                                     \(G_{p} (s) =\frac{1}{0.1s + 1}\)

has the gain \(K_P = 10\). The time units are minutes. How large can the dead time D between the controller and the plant be if the phase margin must be no less than \(40^{\circ}\)?