The coupling of solar energy and high parameter coal-fired units is an effective way to improve the efficiency of solar power generation

reduce unit carbon emissions

and increase unit investment in solar thermal power generation. Through the sorting and analysis of the current coupling mode between solar energy and coal-fired units

this article proposes a deep coupling mode between solar energy and coal-fired units

which uses a solar thermal system to heat the feedwater from the outlet of the high-pressure heater

vaporizes the feedwater

and then enters the boiler superheater for further heating before entering the high-pressure cylinder of the steam turbine. The exhaust steam from the high-pressure cylinder of the steam turbine first enters the solar thermal system for heating

and then enters the boiler reheater for further heating before entering the intermediate pressure cylinder of the steam turbine. By adopting this coupling mode

the boiler can eliminate the economizer and water-cooled wall

and necessary technical modifications need to be made to the powder production system

including the use of hot flue gas powder production

the addition of smoke powder heaters

and the elimination of the boiler’s primary air system. Through energy efficiency analysis of the deep coupling mode

the results show that when the solar thermal system is deeply coupled with a 670 MW ultra supercritical unit

the thermoelectric efficiency can reach 47.31%. The economic analysis of this coupling mode shows that the investment payback period of the coal-fired unit coupled solar thermal system is 4~8 a at different grid prices. By modifying the powder production system and adding a smoke powder heater

the exhaust temperature of the boiler can be maintained without increasing

which provids a good technical basis for further increasing the thermal and electrical efficiency of light energy by raising the feedwater temperature.