热工水力参数对矩形双通道管间脉动的影响

在中国核动力研究设计院热工试验回路上进行了矩形双通道管间脉动试验.对各种热工水力参数的试验研究后得出结论:随着进口过冷度的增加,界限热流密度增大,脉动振幅增大,脉动周期变长,进口过冷度对界限含汽率的影响表现出一定程度的非单值性;随着进口质量流速的增大,界限热流密度增加,界限含汽率减小,脉动振幅增大,脉动周期变短;随着系统压力的升高,界限热流密度和界限含汽率增加,脉动振幅减小,系统压力对脉动周期的影响表现出一定程度的非单值性;根据进口过冷度数Nsub和相变数Npch绘制出的脉动界限图,拟合出判断管间脉动界限的准则关系式:Npch＝3.1419 Nsub 10.014.

Effects of Thermo-Hydraulic Parameters on Flow Oscillation in Double Narrow Rectangular Channels

Flow instability in parallel rectangular channels is one of the important factors to affect the operation safety of the flat-plate-type fuel assembly cores.The experiment of flow oscillations in double narrow rectangular channels has been carried out in the thermo-hydraulic loop in NPIC.The results of experimental research of thermo-hydraulic parameters on characteristics of flow oscillation in double narrow rectangular channels show that:(1)With the increasing of inlet subcooling,the limit heat flux,amplitude and period of oscillation are increased;and effects of inlet subcooling on critical quality of oscillation are of ambiguity.(2)With the increasing of inlet flow velocity,the limit heat flux and amplitude of oscillation are increased;and the critical quality and period of oscillation are reduced.(3)With the increasing of system pressure,the limit heat flux and critical quality of oscillation are increased,the amplitude of oscillation is reduced;and effects of system pressure on period of oscillation are.of ambiguity.(4)Based on the stability boundary map obtained by using Nsub and Npch,an experimental correlation of stability boundary in double narrow rectangular channels has been obtained as follows: Npch=3.1419 Nsub 10.014.