摘要
熔盐换热器因其系统压力低、运行稳定以及经济性能好等特点在太阳能、核能和高温制氢等领域得到广泛应用。由于熔盐运行温度高,冷热流体温差大,导致熔盐换热器主要部件中产生的热应力不可忽略。本文采用流热固耦合方法分析U型管式换热器的温度场与应力场,首先运用计算流体力学(Computational Fluid Dynamics,CFD)分析获取了换热器主要热性能参数,并与实验结果进行对比,最大偏差约3.07%,验证了CFD流体仿真结果的准确性。在此基础上,对熔盐管壳式换热器运行工况下的传热过程进行了详细分析,获得换热器流场和温度场。最后,通过Ansys workbench有限元软件计算得到由流场、压力场和温度场耦合产生的应力场,并着重分析了与换热管及壳体相连接的管板的应力分布,给出了管板最高应力值及某些路径的应力变化规律。结果表明:应力较大的部位发生在管板的布管区与非布管的连接区域,位于近壳侧的换热管内壁处,距离管板下端面约2 mm的位置。可为熔盐换热器实际运行和结构设计提供重要参考。
[Background] With advantages of low system pressure, stable operation and good economic performance, molten salt heat exchanger has recently been widely applied to the field of energy as concentrating solar power, nuclear power engineering, high temperature hydrogen production, and so on. [Purpose] This study aims to analyze the thermal stress generated in the main components of the U-tube heat exchanger due to the high operating temperature of the molten salt and the large temperature difference between the hot and cold fluids. [Methods] Fluidthermal-solid coupling method was adopted in this study. First of all, the main thermal performance parameters of the heat exchanger were obtained by using computational fluid dynamics(CFD) computation, and compared with experimental results to verify the accuracy of the CFD fluid simulation results. On this basis, the heat transfer process was analyzed in details for the molten salt tube-shell heat exchange under the operating condition, and the flow field and temperature field of the heat exchanger were obtained. Finally, the stress field generated by the coupling of flow field, pressure field and temperature field was calculated by Ansys workbench finite element software, and the stress distribution of the tube sheet connected with the heat exchange tube and shell was emphatically analyzed to find the maximum stress value of the tube sheet and the stress change rule of some paths. [Results] The result shows that the CFD fluid simulation method is feasible with a maximum deviation of 3.07%. The larger stress is found at the connection area between the tube plate and the non-tube, which is located near the inner tube wall on the shell-side with about 2 mm away from the lower surface of tube plate. [Conclusions] Results of this study provides important reference for the actual operation and structural deign of molten salt heat exchanger.
作者
陈玉爽
田健
丁梦婷
邹杨
王纳秀
CHEN Yushuang;TIAN Jian;DING Mengting;ZOU Yang;WANG Naxiu(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《核技术》
CAS
CSCD
北大核心
2023年第1期106-113,共8页
Nuclear Techniques
基金
中国科学院战略先导专项(No.XDA02010000)
中国科学院青促会(No.2020263)资助。
关键词
熔盐
流热固耦合方法
应力场分析
U型管式换热器
Molten salt
Fluid-thermal-solid coupling method
Stress analysis
U-tube heat exchanger
