A new concept of a supercritical water (SCW) circulating fluidized bed reactor is proposed to produce hydrogen from coal/biomass gasification. The cyclone is a key component of the reactor system. In this paper, cyclones with a single circular inlet (SCI) or a double circular inlet (DCI) were designed to adapt to the supercritical conditions. We evaluated the separation performance of the two cyclones using numerical simulations. A three-dimensional Reynolds stress model was used to simulate the turbulent flow of the fluid, and a stochastic Lagrangian model was used to simulate the particle motion. The flow fields of both cyclones were three-dimensionally unsteady and similar to those of traditional gas–solid cyclones. Secondary circulation phenomena were discovered and their influence on particle separation was estimated. Analyzing the distribution of the turbulence kinetic energy revealed that the most intensive turbulence existed in the zone near the vortex finder while the flow in the central part was relatively stable. The particle concentration distribution was non-uniform because of centrifugal forces. The distribution area can be divided into three parts according to the motion of the particles. In addition, the separation efficiency of both cyclones increased with the inlet SCW velocity. Because of its perturbance flow, the DCI separator had higher separation efficiency than the SCI separator under comparable simulations. However, this was at the expense of a higher pressure drop across the cyclone.

提出了一种超临界水（SCW）循环流化床反应器的新概念，用于从煤/生物质气化中生产氢气。旋风分离器是反应器系统的关键组成部分。在本文中，设计了具有单圆形入口（SCI）或双圆形入口（DCI）的旋风分离器以适应超临界条件。我们使用数值模拟评估了两个旋风分离器的分离性能。使用三维雷诺应力模型来模拟流体的湍流，并使用随机拉格朗日模型来模拟粒子运动。两个旋风分离器的流场在三维上都是不稳定的，并且类似于传统的气固旋风分离器。发现了二次循环现象，并估计了它们对颗粒分离的影响。分析湍流动能的分布表明，最强烈的湍流存在于涡流探测器附近的区域，而中心部分的流动相对稳定。由于离心力，颗粒浓度分布不均匀。根据颗粒的运动，分布区域可分为三部分。另外，两个旋风分离器的分离效率均随入口SCW速度的增加而增加。由于其扰动流，在可比的模拟下，DCI分离器比SCI分离器具有更高的分离效率。然而，这是以旋风分离器上更高的压降为代价的。