Numerical investigation on startup characteristics of high temperature heat pipe for nuclear reactor

• DOI: 10.1016/j.nucengdes.2021.111180
• Publication Date: 2021-03-27T04:36:21Z
• Authors: Zeqin Zhang; Xiaoming Chai; Chenglong Wang; Hao Sun; Dalin Zhang; Wenxi Tian; Suizheng Qiu; G.H Su
• Keywords: 0211 other engineering and technologies; 02 engineering and technology; 7. Clean energy

Abstract Heat pipe cooled reactor (HPR) has a good adaptability to portable power system, which is popular in recent years. Due to the particularity of alkali-metal working fluid, the deep understanding of startup characteristics of high temperature heat pipe from frozen state is essential for the development of HPRs. In this paper, a three-stage frozen startup model is developed to describe the thermal behavior of heat pipe during the startup process, and the continuum flow in the vapor space is modeled as a one-dimensional compressible flow. A numerical code is carried out, in which the governing equations are discretized by Finite Element Method (FEM), and then the code is used to simulate the startup performance of a NaK heat pipe in HPRs. Numerical results indicate that the heat pipe startup behavior can be well described by the three-stage model. The NaK heat pipe is successfully started with a final consistency temperature of 834 K, although the entire second stage is restricted by the sonic limitation. The startup lasts 1550 s in total, and enters the second and third stage at 230 s and 650 s, respectively. After 1500 s, the maximum Mach number of vapor flow is lower than 0.1, which verifies the rationality of the one-dimensional compressible flow model of vapor. This work could provide a reference for the design and application of HPRs.