| 摘要 |
<p>A blowdown device for limiting excess pressure in a nuclear power plant under fault conditions is intended esp. for a boiling water reactor and consists of one or more condensation tubes having their lower ends immersed in a water pool, their upper ends being connected to the source of steam or steam-gas mixture. The lower, discharge end of the tube is equipped with an inbuilt component throughout its length which has a number of overflow edges for the cooling water in the pool. The pressure and water level fluctuations inside the tube caused by the condensation process cause water to flow over these edges, so that a sprinkling or spraying action provides a large thermal exchange surface between the water droplets and the steam. Increased cooling surface resulting from the splashing action and increased turbulence of the cooling water provide effective rapid heat transfer between steam and water and thus a relatively uniform rate of condensation. In addition, sub-atmospheric pressure waves may cause air to be drawn into the steam space, thus still further reducing the structural loading consequent upon steam pressure.</p> |
