放气式B_4C控制棒

VENT TYPE B_4 C CONTROL RODS

根据表面张力-毛细管现象、液体中浸入式排气孔气泡成长与脱离行为以及基本水力学理论,对潜钟型双放气设计的基本原理进行了讨论,并给出算例与参考结构。分析表明:冷却剂(钠)不渗入潜钟的必要条件是潜钟与冷却剂之间的压差p_g-p_1>4σ/d_i;放气孔直径d_i的最可取值小于0.3mm,冷却剂流速v不是关键参量;放气方案对中等燃耗以下的设计没有显著好处;湿式放气方案特别可取。

Based on the effects of surface tention--capillary, the behavior of gas bubblegrowth and detachment from submerged vent ports and the fundamental theory offluid mechanics,the basic principles of double vent diving bell structure is discus-sed,the reference design is presented. Analysis indicates that the necessary condi-tion for no Na permeation from coolant to diving bell ought to be p_g--p_l>4σ/d_i,the preferable value of d_i ought to be<0.3mm, v is not a critical limited parame-ter,for under--medium burnup design, vented option has no significant advantages,the wetted and vented option is particularly preferred.