高温熔盐在螺旋槽管内流动与传热的数值模拟

A numerical simulation of the flow and heat transfer of high temperature molten salt in the spirally grooved tube

利用Fluent软件对高温三元熔盐在4种不同槽深螺旋槽管内流动传热进行了三维模拟,揭示了高温熔盐在螺旋槽管内强化传热的机理,分析了槽深、雷诺数Re对螺旋槽管传热性能的影响,并进一步对阻力性能进行研究。采用有限容积法对连续性方程、动量方程和能量方程进行离散,采用标准κ-ε湍流模型,用Simple算法求解压力和速度耦合关系。研究结果表明,螺旋槽管3的管内传热努塞尔数Nu模拟值与试验值随Re的变化趋势一致,最大误差为13.5%,且试验值均比模拟值大;在相同的Re下,管内Nu和阻力系数f随着槽深的增加而增加,传热强化效果越好,阻力损失也越大。

Adopting the Fluent software, a 3-D simulation of the flow and heat transfer of the high temperature molten salt in the spirally grooved tube with 4 different groove depths was conducted. The mechanism of the enhanced heat transfer of the salt in the tube was disclosed. The effect of the groove depth and the Reynolds number on the heat transfer performance in the tube was analyzed. A further study of the resistance property was conducted. The finite volume method was employed to discretize the continuity equation, momentum equation and energy equation, and the standard κ-ε turbulence model and the Simple algorithm were adopted to solve the coupling relationship between pressure and speed. The result shows that the simulation and test values of the Nusselt number Nu in the third tube are in agreement with the tendency of the change of the Reynolds number, with the maximum error as 13.5% and the test value being greater than the simulation value. Under the same Reynolds number, the Nu of the heat transfer in the tube and the resistance coefficient f increase with the increase of the groove depth. The better the enhanced heat transfer effect, the greater the resistance loss.