A Comparison of the Transfer Function of the Internal Reactor Loop for the Cases of both Distributed and Lumped Parameters

The power-coolant temperature transfer functions obtained for cases of both distributed and lumped parameters are used to compare three models of the internal reactor loop. The power-coolant transfer functions are considered for two values of the coolant velocity, and the results as attenuation and phase characteristics are presented. After adding the attenuation and phase characteristics of the power-coolant temperature and zero power kinetics transfer functions, the open-loop frequency responses of the examples considered are obtained. Two examples of the closed loop transfer functions are also considered. It is concluded that the distributed model of the thermal processes in the reactor core allows the open loop gain coefficient to he greater in comparison with the lumped model at the same conditions of damping of the closed loop. (C.E.S.)