破冰型大型航标船线型开发设计及破冰阻力评估研究

结合北海航海保障中心大型航标船的破冰功能需求,为本船选取合理的推进功率,对本船具有破冰功能特点的线型设计进行分析论述,同时运用破冰阻力经验公式对本船在一定冰厚和航速下的破冰阻力进行估算,结合冰池试验结果对破冰阻力数据进行对比分析,并进行冰区航行的快速性评估。     

Evaluation of consequence assessment methods for pool fires on water involving large spills from liquefied natural gas carriers

This article concerns thermal radiation hazards associated with unconfined liquefied natural gas (LNG) spills on water. Consequence assessment methods were compared to clarify their model characteristics in large-scale LNG spills from an LNG carrier (LNGC). The consequences of LNG release, pool spread, and pool fire hazards were estimated using the following practical methods: the Federal Energy Regulatory Commission’s (FERC) method, the Sandia National Laboratories’ method, and the Fay method. The sensitivity of consequence analysis results to the breach size of a tank was examined under the assumption that LNG is released from a common type LNGC of 125000 m³ cargo capacity. Consequently, it was found that the FERC method is useful from the practical viewpoint of being applicable to any breach size. Finally, thermal radiation hazards from pool fires involving spills from one of the latest and largest LNGCs (250 000 m³ cargo capacity), which are currently considered for construction, were investigated using the recommended FERC method, and the results are discussed in comparison with those for common type LNGCs. As a result, it was found that the maximum thermal hazard distance is longer by only about 24% compared with the common type LNGC, whereas the spill volume is twice as much.     

海洋核动力平台大破口事故下安全壳压力控制与影响

安全壳是海洋核动力平台的核安全二级耐压舱室,包容反应堆及一回路系统,是设计基准事故工况下限制放射性物质对环境释放的重要屏障。海洋核动力平台采用分散式压水堆型,主管道大破口是一种严重的设计基准事故,导致安全壳内产生高压高温的放射性气体。文章通过对安全壳压力控制技术的对比研究,提出了海洋核动力平台安全壳设计适合采用湿阱抑压控制措施的建议,并研究了压力控制对总体方案改进带来的收益,对海洋核动力平台总体方案设计具有指导意义。