The invention discloses a
seawater desalting device for
tail gas of an engine. The device comprises a superconductive
pipe heat exchanger(4), a vacuum evaporating pot(6) and a condenser(5) which are orderly connected as a whole, wherein the superconductive
pipe heat exchanger(4) is communicated with an
exhaust pipe(2) of the engine through a
flue gas diversion valve(3), and the condenser(5) has a
seawater inlet provided with a sea water replenishing pump(10) and a
condensed water outlet provided with a
vacuum pump(9) and a
fresh water collection pot(8). The invention utilizes the
tail gas of the engine which is the waste energy to produce
fresh water by the
distillation method, which fully utilizes the energy, reduces the emission of pollutants and fully utilizes the
heat energy of the
tail gas; the
seawater desalting device has the advantages of simple running, easy operation and maintenance, low cost, small volume and few requirements of the power section, and can effectively resolve the
water supply problem for sailing warships, civilian ships and
oil drilling platforms which use engines as power sources or use other devices the temperature of the tail gases of which is more than 80 DEG C, as power sources.