HEAT EXCHANGER

摘要

Heat exchange tubes (30) which are formed as flat tubes in which grooves (36) and wave-like protrusions and recesses (33, 34) are formed are arranged parallel to each other in such a manner that the longitudinal direction thereof is aligned with the vertical direction, and a heat exchange medium is caused to flow from a lower inlet (31) to an upper outlet (32). Guide walls (43, 44) are provided to a shell (40). Exhaust gas is caused to flow from an upper inlet (41) to a lower outlet (42), and this causes the exhaust gas to meander in the gaps between flow paths (46a-46d) and the heat exchange tubes (30). The exhaust gas and the heat exchange medium as a whole become counter flows, and the wave-like protrusions and recesses (33, 34) produce a secondary flow in the exhaust gas. As a result, the heat exchange efficiency is improved. The alignment of the longitudinal direction of the heat exchange tubes (30) with the vertical direction and the formation of the grooves (36) and the wave-like protrusions and recesses (33, 34) in the heat exchange tubes (30) can promote the downward discharge of condensed water.