快堆蒸汽发生器小泄漏氢扩散数值模拟

Numerical simulation of hydrogen diffusion in small water/steam leaks in fast reactor steam generators

为了通过微氢泄漏探测系统正确判断快堆蒸汽发生器水 /水蒸汽小泄漏 ,建立了快堆蒸汽发生器水 /水蒸汽向钠泄漏后钠水反应产生的氢沿蒸汽发生器扩散的数值模型。假设为大孔隙多孔介质 ,模拟钠在蒸汽发生器内的流动 ,引入体积孔隙率 ,面渗透率和分布阻力来模拟管束、支撑板对钠流动的扰动。根据钠水 /水蒸汽反应生成的氢气和氢氧化钠在钠中离解动力特性 ,建立氢离子和氢氧根离子的扩散方程。钠回路蒸汽发生器的注水模拟水 /水蒸汽泄漏实验表明

A mathematical model is presented for hydrogen diffusion in a fast reactor shell tube steam generator(SG) with a small water/steam leak to judge small water/steam leaks in SG with a hydrogen meter. The model simulates sodium flow in the steam generator as quasi continuum. The model uses volume porosity, area permeability and distributed resistance to model the tubes and support plates. Meantime, The model of hydrogen and hydroxide ions diffusion is also established with the dissociation of hydrogen gas and NaOH in excess sodium. Water injection experiments in a sodium loop showed that the hydrogen meter response to the predicted hydrogen concentration agreed well with the experiment data.