Industrial waste heat type low-temperature multi-effect sea water desalination system

The utility model discloses an industrial waste heat type low-temperature multi-effect sea water desalination system and a sea water desalination method. The industrial waste heat type low-temperature multi-effect sea water desalination system comprises a flue gas waste heat recovery device for making heat source steam and preheating fed sea water and a low-temperature multi-effect sea water desalination device for carrying out sea water desalination treatment by use of the heat source steam; the low-temperature multi-effect sea water desalination device comprises a first-effect evaporator, a plurality of intermediate-effect evaporators, a last-effect evaporator and a condenser which are connected in series; and the condenser is connected with a vacuumizing device, the first-effect evaporator is connected with a feeding sea water pipe, a plurality of preheaters are connected on the feeding sea water pipe in series, and a fresh water pipe between two adjacent evaporators with different effects penetrates through the preheater. According to the industrial waste heat type low-temperature multi-effect sea water desalination system, sequential water feeding is adopted, the scaling and corrosion problems can be solved, the frequency of cleaning and maintaining the equipment can be reduced, and the sea water desalination treatment cost is low; the low-temperature multi-effect sea water desalination device and exhaust gas waste heat utilization are combined, so that the comprehensive utilization of resources is achieved, the flue gas emission temperature is reduced, the improvement of the desulphurization efficiency is facilitated and the emission of pollutants is reduced.