The invention discloses a
waste heat recovery system and method with discharged
smoke waste heat as a heat source of an
air heater. According to the
waste heat recovery system and method with the discharged
smoke waste heat as the heat source of the
air heater, a low-temperature
economizer and the
air heater are connected through a pipeline to form a first circulation loop, a
circulating pump is arranged on an inlet pipeline of the low-temperature
economizer, and an air heater intake water regulating valve is arranged on an inlet pipeline of the air heater; and the low-temperature
economizer is connected with the circulating water side of a
condensed water heater through a pipeline to form a second circulation loop, the
condensed water side of the
condensed water heater is connected with a low-pressure heater in parallel through a pipeline, and a
booster pump is arranged on a condensed water connecting pipeline between the condensed water side of the condensed
water heater and the low-pressure heater. The
system and method have the advantages that the air heater is reserved, low-temperature
corrosion of an
air preheater is relieved, the low-temperature economizer recovers discharged
smoke waste heat of a boiler, and power generation
coal consumption of a
steam turbine is reduced; and meanwhile, the defects that since the air heater consumes low-pressure suction steam of the
steam turbine, the
heat consumption of the
steam turbine is increased, the temperature of discharged smoke is increased, and the heat efficiency of the boiler is reduced are overcome, and the problems that a low-temperature economizer pipeline system is high in cost and operating reliability requirement are solved.