核电站一回路用机械密封

机械密封在各类核电站的一回路中有大量应用.核电站一回路用机械密封是核电站的关键部件之一,其性能好坏很大程度上决定着核电站能否长周期安全可靠运行.本文以几种具有代表性的核电站反应堆堆型为例,对其一回路用机械密封进行了介绍,这些反应堆分别以水、氦气和液态金属为冷却剂并跨越第二代到第四代核电技术.首先介绍了压水堆核主泵机械密封,分别叙述了美式风格的流体静压型核主泵密封及欧式风格的流体动压型核主泵密封的结构特点、工作原理和最新的基础研究状况;随后介绍了高温气冷堆氦气轮机/氦气风机干气密封的结构特点、使用要求及相应的针对性设计;最后介绍了钠冷快堆钠泵机械密封,包括1种惰性气体缓冲、油膜润滑的三级串联式机械密封和1种直接以液态金属润滑的螺旋槽式机械密封.

Mechanical Seals for Primary Circuit of Nuclear Power Plants

Mechanical seals are widely used in the primary circuits in all kinds of nuclear power plants. In the nuclear power plant, whether a long-period safe and reliable operation can be achieved is largely determined by the quality of the mechanical seal. So mechanical seal used in the primary circuit is regarded as one of the most important parts in the nuclear power plant. In this paper, mechanical seals applied in several typical reactor types were introduced, where water, helium and liquid metal were applied as coolants separately. They cover the range from the second-generation to the fourth-generation nuclear technology. For a start, mechanical seals used in reactor coolant pumps of the pressurized water reactors were illustrated. Their structure, operation principal and recent research status both in American-style, most of which were based on the hydrostatic principal, and European-style, most of which were based on the hydrodynamic principal, were described in detail separately. Then, introduction about the structure, use requirements and specific design of the dry gas seal used in helium turbine or helium fan in the High-temperature gas-cooled reactor are presented. Finally, two kinds of mechanical seals which were used in the sodium pumps of the sodium-cooled fast reactors were introduced. One was inert gas buffered, oil lubricated, three-stage series seal, and the other was the spiral groove mechanical seal directly lubricated by the liquid metal.