To improve the energy utilization efficiency and reduce the coal consumption of power supply of thermal power units

an integrated energy saving device which can synchronously recover the flue gas of boiler and the steam residual heat of small steam turbine of induced draft fan is proposed. In this system

the heat medium water is used as the carrier of energy transfer and transformation. By setting independent small turbine condenser and low-temperature economizer

two different forms of waste heat of steam turbine exhaust and boiler exhaust are recovered together. The heated heat medium water enters into the heater

and the heat is used uniformly to heat the primary air and secondary air of the furnace. Finally

with the help of forced circulation of the heat medium water

the collaborative recovery and utilization of steam flue gas waste heat is realized

and the operation economy of the unit is further improved. The practical operation results show that

this waste heat combined utilization system has the advantages of flexible operation

strong seasonal adaptability and significant energy saving effect. After the system was put into service

the standard coal consumption of the unit reduced by 3.948 g/(kW·h)

the water consumption of the desulfurization system reduced by 20 t/h

and the annual income of single unit increased by about 3.6 million yuan. The experience obtained in this paper can be used as a reference for similar units in the future.