Optimization of Inventory Control Strategy for Part Load Operation in a sCO2 Recuperated Brayton Cycle for a 5 MWth Heat Pipe Micro Modular Reactor

Abstract This study focuses on the implementation of an inventory control strategy for part-load operation in a 5 MWth Recuperated supercritical carbon dioxide (sCO2) Brayton Cycle, integrated with a Heat Pipe-Cooled Micro Modular Reactor (MMR). A preliminary investigation emphasises the crucial role of the inventory tank design for efficient control. However, when relying solely on the inventory tank for control, matching lower power demands is challenging due to the low pressure at the compressor inlet. Without countermeasures, subcritical conditions are reached when the power decreases below 43% of the nominal capacity of the studied system. To overcome this limitation, a combined control strategy which involves increasing the inlet temperature of the compressor is investigated. This allows to reach 8% of the nominal power. The study further investigates the performance of the system under load-following conditions. An aggressive power rate change of 7.5%/min of the full load until 30% of the nominal power is simulated, with the resulting power output closely tracking the demand.