The invention discloses an
industrial waste heat type low-temperature multi-effect sea water desaltation
system and a sea water desaltation method. The
system comprises a
flue gas
waste heat recovery device used for preparing heat source steam and preheating
seawater and a low-temperature multi-effect sea water desaltation device which utilizes the heat source steam to realize sea water desaltation treatment; the low-temperature multi-effect sea water desaltation device comprises a first-effect
evaporator, a plurality of intermediate-effect
evaporator, a final-effect
evaporator and a condenser; the condenser is connected with a vacuum-pumping device; the first-effect evaporator is connected with a feeding
seawater pipe on which a plurality of preheaters are serially arranged; a
fresh water pipe between every two adjacent evaporators penetrates the preheaters. According to the invention, in-order
water supply is adopted, so that the scaling and
corrosion problems are solved, equipment cleaning and maintenance are reduced, and therefore the sea water desaltation cost is low; the low-temperature multi-effect sea water desaltation device is combined with
exhaust heat utilization, so that comprehensive
resource utilization is realized, the
flue gas
discharge temperature is lowered, the desulphurization efficiency is favorably improved and emission of pollutants is reduced.