绕丝结构对氦氙气体流动换热特性影响研究

在开放栅格式气冷空间堆堆芯的设计中，会在燃料棒上采用绕丝结构，这将对工质的流动换热特性产生很大影响。本文采用CFD方法开展了He-Xe混合气体在气冷空间堆典型带绕丝燃料通道内的流动换热特性的数值研究，获得进出口温度、压力、流速及流体密度等参数的空间分布。结果表明引入绕丝使得范宁摩擦因子出现大幅增加，部分绕丝结构会使努塞尔数降低20%～30%，且本文所研究5种绕丝结构热工水力性能比均小于1。研究结果对于气冷空间堆堆芯热设计、提高系统的安全性具有重要意义。

Flow and Heat Transfer Characteristic of He-Xe Gas Mixturewith Helical Wire Structure

In the design of the open grid gas-cooled space reactor core, the helical wires are used on the fuel rods, which will have great influence on the flow and heat transfer characteristics of the working mass. In this paper, the CFD method was used to analyze the flow and heat transfer characteristics of He-Xe gas mixture in an annulus wrapped with a helical wire and the import and export parameters spatial distributions such as temperature, pressure, flow rate and fluid density were obtained. The results show that the introduction of helical wire greatly increases the Fanning friction factor, and some helical wire structures will reduce the Nusselt number by 20%-30%. Moreover, the thermal-hydraulic performance ratios of the five helical wire structures studied in this paper are all less than 1. The research results are of great significance to the thermal design of gas-cooled space reactor core and to improve the safety of the system.