| 摘要 |
<p>. A steam generator has a wound flow pipe which forms an enclosure structure that surrounds an inner chamber, an inner housing which surrounds the jacket and frame therewith a first annular gap for guiding exhaust gas from a burner, an intermediate housing which surrounds the inner housing and forms therebetween a second annular gap through which a combustion air flows to the burner and is heated by the exhaust gas in the first annular gap, and an outer housing which surrounds the intermediate housing and forms a third annular gap through which the combustion air is aspirated from the third gap and is preheated by the combustion air in the second annular gap.</p> |
