| 摘要 |
In the cover chamber (9) of the steel boiler, the inner surface of which forms a first heat exchange surface, a water-conducting conduit is arranged, the one end of which is connected with a back flow conduit (8) and its other end is connected to a forward flow conduit (12). The combustion chamber (1) at its face-side end is provided with a burner (2). The heat exchange surface for transmission of heat from the combustion gases to the hot water is formed by at least two flue gas heat exchangers (3,4) outside the boiler and near to it on the back flow conduit. The heat exchangers in parallel connection are flowed through by a part of the backflow water. Each heat exchanger has a back flow conduit (8a,8b) which are brought together into a single conduit between the heat exchangers and the boiler and connected to the boiler. |
