Flue-gas waste heat recovery device

The utility model discloses a flue-gas waste heat recovery device, which comprises a water supplying part, a pipe-type heat exchanger and a separation-type heat pipe heat exchanger, wherein the pipe-type heat exchanger and the separation-type heat pipe heat exchanger are connected in series. In the using state, the pipe-type heat exchanger is positioned at the high-temperature section of a flue, the evaporation section of the separation-type heat pipe heat exchanger is positioned at the low-temperature section of the flue, and the condensation section of the separation-type heat pipe heat exchanger is positioned outside the flue and is connected with the water supplying part. In the scheme, the suitable temperature range is wide and the device is especially suitable for the situation that the sulphur content of flue gas is higher and the temperature of acid dew point of the flue gas is higher than water supplying temperature.