压力对低干度自然循环流动特性的影响

Effect of System Pressure on Flow Characteristics of a Natural Circulation System with Low Steam Quality

低温核供热反应堆的设计研究和开发,促进了低压、低干度自然循环流动系统中汽水两相混合物流动稳定性的研究。本文论述了在 HRTL-200热工水力学实验回路上,以水为工质,在加热功率为131kW,加热段入口流动阻力因数为25,冷却剂入口欠热度为5～80℃的条件下,针对系统压力变化对流动特性的影响所进行的实验研究。所研究的压力范围为1.0～4.0MPa,实验参数范围覆盖了200MW 核供热堆的运行参数。结果表明,系统自然循环平均流量和两相流振荡区域均随压力的增加而减小,但当压力上升到一定值之后。这两者的下降趋势均明显变缓;在流动不稳定区,随系统压力的升高,流量振荡的相对振幅变小,振荡周期变化不大。

The design and development of nuclear heating reactor promote the study on flow stability of water and steam two phase mixture in a natural circulation system with relatively low pres- sure and low steam quality.When the system pressure was changed from 1.0 to 4.0MPa the experimental results about the flow characteristic,obtained from the test loop HRTL-200 which uses water as coolant,are presented in this paper.The following are experimental condi- tions:heating power is 131kW,flow resistance coefficient on the entrance of test section is 25, and the subcoolings are from 5 to 80℃.The studied parameters cover ones of the 200MW Heating Reactor.The results show that with the increase of system pressure the natural circu- lation mass flow rate will decrease and the instability region will become smaller,but the change tendency will become unobvious after the system pressure is greater than a certain val- ue.With the increase of system pressure the oscillation amplitude of the mass flow rate will de- crease and the vibration period will almost not change in the instability region.