Thermal hydraulic analysis of concentric recuperator of DRAGON-V loop

An experimental Lead Lithium (PbLi) loop named DRAGON-V has been built at the Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences (INEST, CAS). The purpose of this loop is to test the technical issues of PbLi blankets for fusion reactors, such as thermal hydraulics, material corrosion, magnetohydrodynamics (MHD) effect and safety issues, etc. The main heat recovery system of the DRAGON-V loop is the Concentric Recuperator Heat Exchanger (CRHE) which was made of T91 steel. It has counter flow arrangements with PbLi as the working fluid across the tube and shell sides. In this paper, the system was analyzed in detail for thermal performance, pressure drop, pumping power, entropy generation, the effect of inlet temperature of shell side fluid on overall performance, and the temperature distribution and flow characteristics. It was found that the effectiveness and heat transfer rate of the CRHE was decreased with the inlet temperature of the PbLi across the shell side. The difference of effectiveness calculated by correlation and simulation was about 4.5%. The high pumping power of PbLi fluid circulation was required on the shell side due to its thermo-physical properties variation, which resulted in the high pressure drop across the shell side as compared to the tube side. The temperature variation across the tube and shell sides indicated that the simulation results agreed well with the design parameters within a deviation of less than ˜ 5%.