Sludge indirect heat exchange evaporation dehydration coupled pyrolysis carbonization method and system

The invention discloses a sludge indirect heat exchange evaporation dehydration coupling pyrolysis carbonization method. The method comprises the following steps: 1) temporarily storing wet sludge; 2)conveying the wet sludge into a sludge indirect heat exchange evaporation device for heat exchange drying; 3) sending the dried sludge to a pyrolysis carbonization furnace for pyrolysis, separating out moisture and volatile matters in the sludge to form a combustible gas mixture, sending the combustible gas mixture to a pyrolysis gas combustion furnace for combustion, cooling the residual productin the sludge in the form of sludge carbon, and sending the cooled residual product to a storage system; 4) after high-temperature hot flue gas generated by combustion of the pyrolysis gas combustionfurnace provides heat for the carbonization furnace, feeding flue gas subjected to carbonization and heat absorption into a waste heat recovery device, heating the flue gas by using an added fuel togenerate a high-temperature