Control and Safety Studies for an HTR Gas Turbine System

When interest in HTR-GT systems began to develop seriously, it became evident that if, in the Dragon Project, we were to be able to assess sensibly the influences of various system arrangements on reactor design, physics and economics, then we must equip ourselves with the means to study rapidly the steady-state and kinetic behaviour of these arrangements. Unlike steam systems, gas turbine systems do not lend themselves to division into fairly independent parts, of which the reactor is one. The means of study we have been developing are digital computer codes for steady-states and analogue models for kinetics. The steady-state code has been written so that various machine and heat exchanger routes can be specified in the input and also some design parameters. At present only the design parameters of the recuperator can be varied, but the facility will be extended to other elements, the reactor core being of particular interest. In choosing to study kinetics by analogue computer, we bore in mind the difficulties of synthesising from theoretical transfer functions a kinetics system which could be represented on a digital computer using finite time-step methods. We also considered briefly the complete representation of the system by finite difference methods in both space and time. We decided that the former was too difficult and the latter too enormous for either the time or machines we have available.