To improve heat efficiency and to achieve stable combustion in a combustion device by rationally treating dew condensation water in a sub-heat exchanger disposed at a latter part of a main heat exchanger.
The main heat exchanger 4 and the sub-heat exchanger 5 are disposed at an upstream side and a downstream side of a combustion gas flow channel 3 of the combustion device 2, the sub-heat exchanger 5 is constituted by penetrating a heat medium tube 13 through a fin block 12 constituted by arranging a number of heat absorption fins 11 at intervals, the heat absorption fins 11 are arranged in such manner that a combustion gas flows downward through the intervals, and a plurality of water dripping projections 15 are projected downward from a lower end of each heat absorption fin 11, thus the dew condensation water can be concentrated on the dewatering projections 15, and the formation of a water film by surface tension can be prevented.
COPYRIGHT: (C)2008,JPO&INPIT
KANEZAKI KOICHI
SHIBATA YASUSHI
Hiroki Naito
Daisuke Nagano