Preliminary Study on Features of Key Components for HTGR Helium Turbine System

High temperature gas cooled reactor (HTGR) is featured by inherent safety. With high outlet temperature, HTGR is of potentially economical competitiveness. Helium turbine system can take advantage of high temperature helium to achieve high efficiency as well as compact structure, with development perspective. Key components of HTGR helium turbine system include rotary machinery such as turbo compressor and motor/generator, and heat transfer components (i.e. precooler, intercooler, recuperator and nuclear reactor). Due to the closed cycle, the features of key components are not independent. This paper preliminary explores the inherent relationships among features of key components, especially changing with reactor power. For heat transfer components, the general relationship between pressure drop and the effectiveness of heat transfer is analyzed. Furthermore, it is found that the pressure drop in recuperator, precooler and inter-cooler depends on the reactor power with engineering constraints. Besides, There exists the approximate squared relation between power and pressure drop in heat exchangers. For rotary machinery, it is found that the moment of inertia is the function of reactor power. For example, the moment of inertia of motor/generator is proportional to the reactor power. The relationship between moment of inertia of turbo-compressors and reactor power is more complex. This study is expected to be helpful to the design of key components for HTGR helium turbine system and can be applied to analyze the cycle’s dynamic characteristics.