自然循环反应堆全寿期流量分配多目标优化研究

The design of core flow distribution is a key aspect of the core structure optimization of natural circulation reactors and is of great significance for enhancing the economy and safety of the core. A locally optimal flow distribution calculation model was constructed based on the closed parallel multi-channel model of the reactor, and the existing flow distribution schemes were analyzed. In view of their limitations, a multi-objective comprehensive evaluation method based on the optimal time zone was proposed, which can realize the optimization calculation of multi-objective flow distribution for the entire life cycle of the reactor. According to the proposed theory, combined with the TOPSIS comprehensive evaluation method, taking the maximum output power under natural circulation, the maximum temperature difference at the outlet during the reactor life cycle, and the standard deviation of the maximum temperature difference changing with time as attribute values, the optimization research on the core flow distribution scheme of the small long-life natural circulation lead-bismuth fast reactor SPALLER - 100 was carried out. The research results show that the core flow distribution scheme of the SPALLER - 100 reactor obtained based on the power distribution at an operating time of 3182 days is the best. Compared with the flow distribution scheme obtained based on the power distribution at the beginning of the life cycle, the maximum temperature difference at the core outlet of the obtained scheme is reduced by 30 K, the standard deviation of the maximum temperature difference at the core outlet changing with time is reduced by 41%, and the maximum output power of the reactor's natural circulation is increased by 2.35%.

堆芯流量分配设计是自然循环反应堆堆芯结构优化的重点内容,对提升堆芯经济性和安全性具有重要意义。基于反应堆闭式并联多通道模型构建了局部最优流量分配计算模型,并对现有的流量分配方案进行分析,针对其局限性,提出了一种基于最佳时区的多目标综合评价法,可实现反应堆全寿期多目标流量分配优化计算;根据所提出的理论,结合TOPSIS综合评价法,以自然循环下最大输出功率、反应堆寿期内出口最大温差以及最大温差随时间变化标准偏差为属性值,开展小型长寿命自然循环铅铋快堆SPALLER-100的堆芯流量分配方案优化研究。研究结果表明,基于运行时间为3182 d功率分布所得SPALLER-100反应堆堆芯流量分配方案最佳,与基于寿期初功率分布所得流量分配方案相比,所得方案堆芯出口最大温差降低30 K,堆芯出口最大温差随时间变化的标准偏差降低41%,反应堆自然循环最大输出功率提高2.35%。