Cooling system for bottom slag of fluidized bed boiler

The utility model discloses a circulating cooling system for bottom slag of a fluidized bed boiler, which comprises a cooling unit connected with the boiler, a control unit and a deslagging unit, wherein the cooling unit comprises water-cooled roller slag coolers and a negative pressure air-cooled steel band machine, a closed casing is arranged at the periphery of the negative pressure air-cooled steel band machine in a sleeving manner, a cooling air inlet and a cooling air outlet are formed in the casing, the cooling air inlet is connected with an air blower, the cooling air outlet is connected with a furnace chamber of the boiler, and the air ingoing direction is opposite to the conveying direction of the negative pressure air-cooled steel band machine; the deslagging unit comprises a slag bin and a deslagging valve arranged on the slag bin; the control unit is a PLC control system. The cooling system has the benefits that the slag can be cooled quickly, the recovery of waste heat is high, the consumption o