基于运行数据的船用堆波动管热分层现象研究

基于运行数据将船用堆波动管热分层划分为升功率、降功率、变工况、小喷淋流量4类典型瞬态，对4类典型瞬态分别进行无量纲里查德森数（Ri）分析、瞬态工况数值模拟计算，得到波动管在4类典型瞬态下水平管段的热分层区间长度、持续时间和最大温差。结果表明，升功率和降功率瞬态热分层仅单次贯穿波动管，升功率瞬态的接头部位循环的热波动以及小喷淋流量瞬态水平段的长区间、长时间、大温差的热分层现象和变工况导致的热应力波动可能影响到波动管的安全。本文提出的基于运行数据的波动管热分层现象研究方法为后续热应力和热疲劳分析奠定了基础，同时可以为其他容积设备热分层研究提供参考。 

Study on Thermal Stratification of Marine Reactor Surge Line Based on Operating Data

The thermal stratification of marine reactor surge line is divided into four types of typical transient based on the operating data: power increase, power decrease, off-design conditions, and small spray flow. The dimensionless Richardson number (Ri) analysis and the numerical simulation calculation of transient conditions are performed separately for these typical transients, generating the thermal stratification section length, duration and maximum temperature difference along the horizontal line section of the surge line under these typical transients. As indicated by the results, the thermal stratification under power increase and decrease transient conditions extends through the surge line just once, and the surge line safety may be affected by the circulating thermal fluctuation at the joint under the power increase transient condition, the thermal stratification of long section, long time and large temperature difference in the horizontal section under the small spray flow transient condition, and the thermal stress fluctuation caused by the off-design conditions. The method of study on thermal stratification of surge line based on operating data, proposed in this paper, lays a foundation for the subsequent thermal stress and thermal fatigue analyses, and also provides reference for the thermal stratification studies of other volumetric equipment.