Dynamic modelling and control system design of micro-high-temperature gas-cooled reactor with helium brayton cycle

Abstract

It is possible to use the micro-high-temperature gas-cooled reactor with helium Brayton cycle (Mi-HTR) as a mobile micro-nuclear power source to provide a stable power supply. Because the Mi-HTR is a highly integrated system, the devices involved are highly coupled and mutually constrained. Therefore, the dynamic model of 5 MW Mi-HTR was established through theoretical derivation. Compared with the design value, the maximum error of steady-state calculation results is less than 2%, and the temperature error is less than 1 K. The transient behaviour is consistent with the experimental trend. The maximum relative error of flow is less than 1.5%, and the maximum relative error of pressure is less than 2.8%. On this basis, the characteristics of Mi-HTR such as large time delay, nonlinear, strong coupling and parameter time-varying are obtained by analysing the dynamic characteristics. The steady-state operation scheme of Mi-HTR is proposed. The reactor outlet helium temperature control, the electric power/rotor speed control, and the precooler/intercooler outlet helium temperature control are designed. A dynamic control model for Mi-HTR is established. The designed control system can cope with the 33% step change of external load.