The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and ...The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and the results matched well with those of previous researches. The Reynolds number based on the diameter of the primary cylinder is 500. The diameter ratio between the control rod and the primary cylinder （d/D） is 0.25. It was found that the effect of the combination of one upstream tandem control rod and one staggered control rod on the hydrodynamics of the primary cylinder is a linear superposition of the effect of a corresponding single control rod, and the effect of the upstream tandem control rod is dominant at larger spacing ratios such as G/D=2. For the combination of a downstream tandem control rod and a staggered control rod, the effect of the control rods is different from that of the corresponding single control rod in the region of 0.2〈G/D〈0.5 ＆ 30°〈a〈120° and 0.9〈G/D〈1.4 ＆ 30°〈a〈50°, where the additional effect is obvious. In this case, the effect of the downstream tandem control rod is dominant at small spacing ratios （such as G/D=0.1）. At moderate spacing ratios such as G/D=0.4, the effects of the tandem control rod and the staggered control rod are comparable in both cases.展开更多
熔盐堆是第四代反应堆中唯一一种以液体为燃料的反应堆,因此对于熔盐堆反应性的研究不同于其他反应堆。基于蒙特卡洛方法,利用Monte Carlo N-Particle(MCNP)软件模拟控制棒在堆芯径向不同位置及轴向不同插入深度对熔盐堆堆芯有效倍增因...熔盐堆是第四代反应堆中唯一一种以液体为燃料的反应堆,因此对于熔盐堆反应性的研究不同于其他反应堆。基于蒙特卡洛方法,利用Monte Carlo N-Particle(MCNP)软件模拟控制棒在堆芯径向不同位置及轴向不同插入深度对熔盐堆堆芯有效倍增因数的影响。随后将熔盐堆堆芯由上到下划分成八个区域,分别计算熔盐与石墨在八个不同区域发生多普勒效应,以及发生膨胀效应对整个堆芯的有效倍增因数的影响。结果表明控制棒位于熔盐堆不同位置对反应堆有效倍增因数影响不同,沿径向21.21 cm处插入深度80 cm时控制棒有效利用价值最高。熔盐在不同区域发生多普勒效应时,顶部和底部对反应堆有效倍增因数影响相对较大。不同区域熔盐发生膨胀效应时,轴向中心处对有效倍增因数的影响相对较大。石墨发生局部温度扰动对有效倍增因数的影响较小。展开更多
基金the support from the National Natural Science Foundation of China(Nos.11372188,and 51490674)the National Basic Research Program of China(973 Program)(No.2015CB251203)
文摘The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and the results matched well with those of previous researches. The Reynolds number based on the diameter of the primary cylinder is 500. The diameter ratio between the control rod and the primary cylinder （d/D） is 0.25. It was found that the effect of the combination of one upstream tandem control rod and one staggered control rod on the hydrodynamics of the primary cylinder is a linear superposition of the effect of a corresponding single control rod, and the effect of the upstream tandem control rod is dominant at larger spacing ratios such as G/D=2. For the combination of a downstream tandem control rod and a staggered control rod, the effect of the control rods is different from that of the corresponding single control rod in the region of 0.2〈G/D〈0.5 ＆ 30°〈a〈120° and 0.9〈G/D〈1.4 ＆ 30°〈a〈50°, where the additional effect is obvious. In this case, the effect of the downstream tandem control rod is dominant at small spacing ratios （such as G/D=0.1）. At moderate spacing ratios such as G/D=0.4, the effects of the tandem control rod and the staggered control rod are comparable in both cases.
文摘熔盐堆是第四代反应堆中唯一一种以液体为燃料的反应堆,因此对于熔盐堆反应性的研究不同于其他反应堆。基于蒙特卡洛方法,利用Monte Carlo N-Particle(MCNP)软件模拟控制棒在堆芯径向不同位置及轴向不同插入深度对熔盐堆堆芯有效倍增因数的影响。随后将熔盐堆堆芯由上到下划分成八个区域,分别计算熔盐与石墨在八个不同区域发生多普勒效应,以及发生膨胀效应对整个堆芯的有效倍增因数的影响。结果表明控制棒位于熔盐堆不同位置对反应堆有效倍增因数影响不同,沿径向21.21 cm处插入深度80 cm时控制棒有效利用价值最高。熔盐在不同区域发生多普勒效应时,顶部和底部对反应堆有效倍增因数影响相对较大。不同区域熔盐发生膨胀效应时,轴向中心处对有效倍增因数的影响相对较大。石墨发生局部温度扰动对有效倍增因数的影响较小。
