Control principles for NPP with a dissociating coolant

The use of a dissociating gas as a coolant and a working substance for NPP enables the realization of a gas-liquid thermodynamic cycle in a single-circuit scheme. A small metall volume of turbines with a dissociating working substance as opposed to turbines of the same capacity operating on water vapour results in the decrease of inertia moments. Besides, small time constants of warming-up gas volumes and reactor metal mass result in the increase in requirements for response of a number of controllers. The control principles for NPP appear to be substantially different in the presence of a circulating pump with a steep or sloping curve for consumption-head. Various structural schemes of a single-circuit NPP control have been investigated on an analog computer. To find out advantages and disadvantages of fast response systems of frequency control, the investigation of various procedures of frequency control has been performed using: 1) a throttle valve with a pneumatic drive; 2) a hydrolically driven throttle valve; 3) mechanical or electric ballast loads. The use of a quasi-optimum control law permitting a simultaneous dynamic consideration of a change in the time constant and the gain coefficient of a turbine as well as real dynamics of the drive is one of the ways to increase the fast response of a frequency controller