Thermal hydrodynamic modeling and simulation of hot-gas duct for next-generation nuclear reactor

• Published in: Nuclear engineering and design Vol. 310; pp. 27 - 38
• Main Authors: Lee, Injun, Hong, Sungdeok, Kim, Chansoo, Bai, Cheolho, Hong, Sungyull, Shim, Jaesool
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.2016; Elsevier BV
• Subjects: Computational fluid dynamics; Computer simulation; Convection; Convection modes; Emissivity; Energy research; Fluid flow; Fluid mechanics; Heat exchangers; High temperature gas cooled reactors; Hydrogen; Hydrogen production; Mathematical models; Nitrogen; Nuclear energy; Nuclear reactors; Nusselt number; Porosity; Process heat; Radiation; Reactors; Simulation; Temperature requirements; K. Thermal Hydraulics
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2016.10.002

•Thermal hydrodynamic nonlinear model is presented to examine a hot gas duct (HGD) used in a fourth-generation nuclear power reactor.•Experiments and simulation were compared to validate the nonlinear porous model.•Natural convection and radiation are considered to study the effect on the surface temperature of the HGD.•Local Nusselt number is obtained for the optimum design of a possible next-generation HGD. A very high-temperature gas-cooled reactor (VHTR) is a fourth-generation nuclear power reactor that requires an intermediate loop that consists of a hot-gas duct (HGD), an intermediate heat exchanger (IHX), and a process heat exchanger for massive hydrogen production. In this study, a mathematical model and simulation were developed for the HGD in a small-scale nitrogen gas loop that was designed and manufactured by the Korea Atomic Energy Research Institute. These were used to investigate the effect of various important factors on the surface of the HGD. In the modeling, a porous model was considered for a Kaowool insulator inside the HGD. The natural convection and radiation are included in the model. For validation, the modeled external surface temperatures are compared with experimental results obtained while changing the inlet temperatures of the nitrogen working fluid. The simulation results show very good agreement with the experiments. The external surface temperatures of the HGD are obtained with respect to the porosity of insulator, emissivity of radiation, and pressure of the working fluid. The local Nusselt number is also obtained for the optimum design of a possible next-generation HGD.