Numerical Investigation of LBE Flow and Heat Transfer Characteristics in Helical-coiled Tube Bundles with Different Coil Strategies
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摘要: 螺旋管式直流蒸汽发生器(H-OTSG)被广泛应用于液态金属反应堆的设计中,其中相邻的径向螺旋管束可以布置为同一旋向或相反旋向,不同的旋向策略会影响到蒸汽发生器壳侧的流动行为。为探究不同旋向对螺旋管束中铅铋流动与传热特性的影响,采用剪切应力输运(SST k-ω)模型、湍流模型和Kays湍流普朗特数(Prt)模型对其进行数值模拟研究。首先通过现有液态金属横掠棒束实验对数值方法进行了验证;其次建立了同一旋向和交替旋向2种螺旋管束模型,比较了其传热和阻力的差异;最后从流场的角度对产生差异的原因进行了分析。结果表明,交替旋向的螺旋管束中的阻力和传热分别比同一旋向管束高7.1%和4.4%,这是因为交替旋向管束中的速度场更均匀且湍流交混更强。
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关键词:
- 螺旋管式直流蒸汽发生器(H-OTSG) /
- 铅铋 /
- 旋向策略 /
- 数值模拟
Abstract: Helical tube once-through steam generators (H-OTSG) are widely used in the design of liquid metal reactors, in which adjacent radial tube bundles can be coiled in the same direction or opposite direction, and different coil strategies will affect the flow behavior on the shell side of the steam generator. To explore the lead-bismuth eutectic (LBE) flow and heat transfer characteristics in helical tube bundles with different coil strategies, the shear stress transport (SST k-ω) model, turbulence model and Kays turbulent Prandtl number (Prt) model are used for numerical simulation. First, the numerical method is validated by existing experiments of liquid metal flow cross tube banks. Then, helical-coiled tube bundles with the same coiling direction and alternate coiling direction are established, and the differences in heat transfer and flow resistance are compared. Finally, the reason for the differences is analyzed from the perspective of the flow field. The results show that the flow resistance and heat transfer in the helical-coiled tube bundle with alternate coiling direction are 7.1% and 4.4% higher than those with the same coiling direction respectively. This is due to the stronger turbulent mixing and more uniform velocity field in the alternate-coiled bundle. -
表 1 不同网格划分下的换热系数和压降
Table 1. h and Δp under Different Grid Strategies
网格数量/个 0.83×106 2.77×106 4.62×106 h/[W·(m2·K)−1] 35963.63 37174.86 37082.44 Δp/Pa 3950.28 4124.75 4193.61 -
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