Since 2006, the superconducting toroidal field（TF） coils of the Experimental Advanced Superconducting Tokomak（EAST） have been successfully cooled by supercritical helium at a temperature of 4.5 K and a pressure of...Since 2006, the superconducting toroidal field（TF） coils of the Experimental Advanced Superconducting Tokomak（EAST） have been successfully cooled by supercritical helium at a temperature of 4.5 K and a pressure of 4 bara in eleven experiments. To obtain higher operating currents and magnetic fields it is necessary to lower the operating temperature of the TF coils.The EAST sub-cooling helium cryogenic system, with a warm oil ring pump（ORP）, was tested twice in cool-down experiments, which made the TF coils operate at 3.8 K. However, the long term operational stability of the sub-cooling system cannot be guaranteed because of the ORP＇s poor mechanical and control performance. In this paper, the present status of the EAST subcooling helium cryogenic system is described, and then several cooling methods below 4.2 K and their merits are presented and analyzed. Finally, an upgrading method with a cold compressor for an EAST sub-cooling helium cryogenic system is proposed. The new process flow and thermodynamic calculation of the sub-cooling helium system, and the main parameters of the cold compressor, are also presented in detail. This work will provide a reference for the future upgrading of the sub-cooling helium system for higher operation parameters of the EAST device.展开更多
CIPS(Crud Induced Power Shift),是指反应堆冷却剂系统内腐蚀积垢物在燃料棒表面沉积而导致轴向功率峰值向堆芯入口处偏移的现象。这一现象会影响核电厂运行的安全性,如:使降功率时轴向功率分布控制困难、停堆裕量减少、反应堆启堆时...CIPS(Crud Induced Power Shift),是指反应堆冷却剂系统内腐蚀积垢物在燃料棒表面沉积而导致轴向功率峰值向堆芯入口处偏移的现象。这一现象会影响核电厂运行的安全性,如:使降功率时轴向功率分布控制困难、停堆裕量减少、反应堆启堆时的临界工况评价出现偏差等,进而影响经济性。本文阐述了CIPS现象的成因、危害、风险降低途径,并使用3D核设计程序、热工-水力子通道程序和CIPS评价专用程序对AP1000核电厂首循环的CIPS风险进行了分析并给出了降低风险的建议。展开更多
基金supported by National Natural Science Foundation of China(No.11505237)
文摘Since 2006, the superconducting toroidal field（TF） coils of the Experimental Advanced Superconducting Tokomak（EAST） have been successfully cooled by supercritical helium at a temperature of 4.5 K and a pressure of 4 bara in eleven experiments. To obtain higher operating currents and magnetic fields it is necessary to lower the operating temperature of the TF coils.The EAST sub-cooling helium cryogenic system, with a warm oil ring pump（ORP）, was tested twice in cool-down experiments, which made the TF coils operate at 3.8 K. However, the long term operational stability of the sub-cooling system cannot be guaranteed because of the ORP＇s poor mechanical and control performance. In this paper, the present status of the EAST subcooling helium cryogenic system is described, and then several cooling methods below 4.2 K and their merits are presented and analyzed. Finally, an upgrading method with a cold compressor for an EAST sub-cooling helium cryogenic system is proposed. The new process flow and thermodynamic calculation of the sub-cooling helium system, and the main parameters of the cold compressor, are also presented in detail. This work will provide a reference for the future upgrading of the sub-cooling helium system for higher operation parameters of the EAST device.
文摘CIPS(Crud Induced Power Shift),是指反应堆冷却剂系统内腐蚀积垢物在燃料棒表面沉积而导致轴向功率峰值向堆芯入口处偏移的现象。这一现象会影响核电厂运行的安全性,如:使降功率时轴向功率分布控制困难、停堆裕量减少、反应堆启堆时的临界工况评价出现偏差等,进而影响经济性。本文阐述了CIPS现象的成因、危害、风险降低途径,并使用3D核设计程序、热工-水力子通道程序和CIPS评价专用程序对AP1000核电厂首循环的CIPS风险进行了分析并给出了降低风险的建议。
