首先最重要的一点：如果煤气管道内着火，应立即封闭所有入孔、放散管、采封管，并向管道内通大量蒸汽灭火。

First of all the most important point: if the gas pipeline inner fire, immediately closed all into the hole, radiation tube and sealing pipe, and in general to pipe of steam to extinguish fire.

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介绍了一种双面换热的套管式直流蒸汽发生器，其元件由直管外管和螺旋内管组成。

The once-through steam generator with double-side heat transfer component was presented in this paper. And the component is composed of straight tube outside and helix tube inside.

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