Waste heat recycling device and method for boiler flue gas of thermal power plant

The invention provides a waste heat recycling and reusing device and method for thermal power plant boiler flue gas, belongs to the technical field of energy recycling, and aims to solve the problems that a traditional coal-fired thermal power device is low in energy conversion efficiency, and equipment such as a thermal power plant boiler is too large in coal heat energy waste amount, poor in energy utilization rate and high in energy purchasing cost. A coil pipe is arranged in the double-layer shell; a reservoir is arranged on one side of the double-layer shell; a heat exchange plate is arranged in the double-layer shell; and a generator is arranged on one side of the double-layer shell. According to the system, waste gas generated by coal combustion is subjected to gradient heating by combining heat gradient utilization three-thermonuclear hot water circulation heat absorption equipment, so that flue gas waste heat and condensation heat generated by a steam turbine are recycled by utilizing a first-class a