Comparative Evaluation of Energy-Saving Benefits of Flue Gas Waste Heat Utilization Under the Background of Coal Power Upgrading

The energy saving and emission reduction transformation of thermal power enterprises can reduce the coal consumption of thermal power supply, and then effectively reduce the growth of carbon dioxide emissions, which is of great significance to achieve the goal of carbon peak and carbon neutralization. Taking a 630 MW unit as an example, the system units of four waste heat utilization schemes (low-temperature economizer scheme, secondary low-temperature economizer scheme, bypass flue scheme and turbine boiler coupling scheme) were compared, and the key technical parameters and power saving effect were compared and analyzed. Moreover, a reference for the upgrading and technical transformation of energy conservation and emission reduction in China’s power industry was put forward. The results show that the exhaust gas temperature is reduced to 90 ℃, The coal consumption rate of power supply is reduced by 1.88 g/(kW⋅h) in the low-temperature economizer scheme, 2.16 g/(kW⋅h) in the secondary low-temperature economizer scheme, 2.29 g/(kW⋅h) in the bypass flue scheme, and 2.66 g/(kW⋅h) in the turbine boiler coupling scheme.