A control method for combined cycle coupled with HTGR at part load

An efficient power conversion scheme and its characteristics at part-load conditions are crucial for the thermal system. The combined cycle coupled with HTGR is able to achieve the cascaded utilization of energy, which includes the topping closed Brayton cycle and the bottoming Rankine cycle. This paper provided an effective control method for part load of combined cycle coupled with HTGR. When the power of the combined cycle changes, the topping cycle is controlled by helium inventory, and the bottoming cycle works under constant pressure. The mass flow of steam is changed with helium synchronously. This control method can keep the cycle efficiency at a high level: when the load is changed from 100% to 30%, the cycle efficiency just decreases by 5.1%. This is a new control method, which can ensure the inherent safety of HTGR in a wide range of power. (author)