Thermal Efficiencies of Alternative Combined Cycle: Nitrogen/Helium Brayton and Subcritical-Pressure Rankine Cycles

Abstract

Currently, 446 nuclear-power reactors are connected to electrical grids in the world. All these reactors are connected only to SubCritical-Pressure (SubCP) Rankine cycle of various thermodynamics arrangements. The maximum thermal efficiency, which is nowadays the driving force for all advances in the nuclear-power industry, is up to 43%. However, Thermal Power Plants (ThPPs) have reached thermal efficiencies of 55% at coal-fired PPs with the SuperCritical Pressure (SCP) Rankine cycle and 62.5% at gas-fired PPs with the combined cycle. Therefore, to compete with ThPPs Nuclear PPs (NPPs) have to increase thermal efficiencies quite substantially. This is only possible with High-Temperature Reactors (HTRs) equipped with SCP Rankine cycles or combined cycles. Therefore, the current paper presents an analysis of the one alternative combined power cycle for HTRs.