EXHAUST GAS RESIDUAL HEAT RECOVERY DEVICE

PROBLEM TO BE SOLVED: To provide an exhaust gas residual heat recovery device having a simple structure and capable of preventing wetting and drying cycle in a condensation economizer.SOLUTION: The exhaust gas residual heat recovery device 1 includes a dry economizer 2 using sensible heat of an exhaust gas for heating water to be heated, and the condensation economizer 4 disposed on a downstream side of the dry economizer 2 and using condensation latent heat of the exhaust gas for heating the water to be heated, in a duct leading to a chimney 10 discharging the exhaust gas to the atmosphere. The duct is composed of a first stage duct 6 provided with the dry economizer 2, and a latter stage duct 8 connected to the first stage duct 6 and changing exhaust gas flow into rising flow, provided with the condensation economizer 4 in the latter stage duct 8, and configured so that the exhaust gas reaches a condensation temperature in the vicinity of an upper part 5 of the condensation economizer 4.