Flue gas and slag waste heat gradient utilization system of circulating fluidized bed combined heat and power generation unit

The utility model belongs to the technical field of circulating fluidized bed combined heat and power generation units, and particularly relates to a circulating fluidized bed combined heat and powergeneration unit flue gas slag waste heat gradient utilization system which comprises a slag cooler booster pump, a slag cooler, a low-temperature economizer booster pump, a low-temperature economizer,a heat supply network circulating water pump and a heat supply network heater. Wherein a water inlet of the slag cooler is connected with a water outlet of the slag cooler booster pump, the slag cooler booster pump is connected with a heat supply network water return pipeline, a water outlet of the slag cooler is connected with a booster pump of the low-temperature economizer, the booster pump ofthe low-temperature economizer is connected with a water inlet of the low-temperature economizer, and a water outlet of the low-temperature economizer is connected with a heat supply network water supply pipeline. A water inle