| 摘要 |
The fluid medium to be heated passes through an initial heating system (2,3) and at least one following heating system (5,6). Each heating system has heat exchangers (2,5) in contact with the medium flow, with higher temp. levels at the second system (5,6) than in the first (2,3). The direct medium flow into the first heating system (2,3) is reduced, to accelerate the increase in temp. and, in extreme cases, is stopped, and the medium within the first system (2,3) is recirculated. The medium can be fed directly to the second heating system (5,6), with medium recirculation in the first system (2,3) or a combined recirculation in both systems (2,3;5,6). |
