Design research for the porous hexagonal prism shaped fuel element adopted in nuclear thermal propulsion reactor based on neutronics and thermal-hydraulics coupled method. (January 2021)

• Record Type: Journal Article
• Authors: Zhang, Jun; Wang, Chenglong; Zhang, Jing; Zhang, Dalin; Tian, Wenxi; Qiu, Suizheng; Su, Guanghui
• Is Part Of: Annals of nuclear energy. Volume 150(2021)
• Publication Date: 2021-01
• Subjects: Nuclear thermal propulsion -- Porous prismatic fuel element -- Neutronics-thermal-hydraulics coupling -- Fuel element design research; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2020.107847
• Languages: English
• ISSNs: 0306-4549

Abstract

Abstract: The Porous hexagonal prism shaped fuel element has the advantages of simple structure, high reliability and good practicability. It has been widely adopted by many nuclear thermal propulsion (NTP) reactor designs. A design method is present in this paper for determining key geometrical parameters of the porous hexagonal prism shaped fuel element. Four sets of fuel elements geometrical parameters are involved, including cases of 127, 169, 217 and 271 cooling passages. And they adopt different flow hole void fractions to have the same distance between adjacent cooling passages, this is done in order to ensure the reliability of fuel element. Three-dimensional neutronics/thermal-hydraulics coupled analyses of them are conducted to study their thermal hydraulic performances. The distributions of power density, coolant mass flow, temperature, coolant velocity and total pressure are obtained. The results indicate that the fuel element with larger numbers of cooling passages and smaller flow hole void fraction tends to have more uniform flow distribution, and the heat transfer efficiency of fuel element is improved at the same time. But those performance improvements by increase in numbers of cooling passages become much smaller when the number of cooling passages exceeds a certain value. Meanwhile, each additional of cooling passages would lead to almost doubled increase in the flow resistance of fuel element. Finally, through contrastive analyses, one set of geometric parameters is considered as the optimal choice which could ensures excellent heat transfer performance and relatively low flow resistance. This study could help set appropriate geometrical parameters for porous hexagonal prism shaped fuel element, thus being beneficial to improve the thermal-hydraulic performance of NTP reactor.