不同稳压器布置方式对超临界二氧化碳自然循环流动不稳定性影响实验研究

Experimental Investigation on Influences of Different Pressurizer Layout Patterns on Supercritical Carbon Dioxide Natural Circulation Flow Instability

摘要: 流体的可压缩性是诱发流动不稳定性的必要条件。在反应堆系统中稳压器是利用流体的可压缩性稳定压力的主要设备。本文开展了不同稳压器布置方式，包括稳压器接入冷段、热段、全接以及全关等四种情况下，超临界二氧化碳自然循环流动不稳定性实验研究，观察并记录了流动不稳定过程中瞬时温度、流量、压力等演化规律，分析了不同的稳压器布置方式对自然循环流动不稳定性的影响机理。研究结果表明：超临界二氧化碳在自然循环工况下，稳压器接入冷段，回路流量波动最大，其余方式波动较小；无论稳压器哪种布置方式，回路出口温度皆有波动，其中接入冷段波动最大；综合来看稳压器接入热段时有助于抑制和消除自然循环回路中的振荡，对控制回路的稳定性最有利。本文成果可为探明可压缩空间对不稳定的影响规律以及稳压器合理布置提供参考和借鉴。

Abstract: The compressibility of fluid is the essential condition to trigger flow instability. Pressurizer is the main equipment that takes advantage of fluid’s compressibility to stabilize the pressure in a nucle-ar reactor system. This paper carried out experiments on supercritical carbon dioxide natural cir-culation flow instability with 4 different layout patterns of the pressurizer, including pressurizer accessing into the cold leg, hot leg, all in and all off, respectively. The evolution law of transient temperature, flow rate and pressure was observed and recorded, and the influences of the mecha-nism of different layout patterns of pressurizer on natural circulation flow instability were analyzed. In the natural circulation of supercritical carbon dioxide, the flow fluctation of the loop is the largest when the pressureizer is accessing into the cold section, and the rest is small. There are tempera-ture fluctuations at the outlet whatever the layout pattern is, among which when pressurizer ac-cessing the cold leg has the highest fluctuations. On the whole, it will be helpful for restraining or eliminating oscillation in the natural circulation when the pressurizer accesses the hot leg, and which turns out to be the most beneficial for stability. The results in this study can be useful for the investigation on the flow instability of mechanisms and the reasonable layout patterns for the pressurizer.