With the continuous progress of the work of “carbon neutrality and carbon peak”

the installed scale of photovoltaic

wind power and other new energy is expanding

energy saving and consumption reduction as well as flexibility improvement become the two key tasks the thermal power units faced. Through mathematical modeling and hourly calculation analysis for the hybrid system

performance and economic characters for solar-thermal systems replacing high pressure heaters are obtained. The calculation results indicate that

using solar thermal and coal fired hybrid system can realize sharp decline of the unit coal consumption

which is a most direct and effective method for coal saving and reducing consumption

it has great significance for life prolonging of the units to be retired from active service because of high coal consumption indexes. However

the economic benefit of the system itself is insufficient. So it can be supplemented with molten salt electric heater to improve the system's frequency modulation ability and enhance the project's profitability. According to the calculation

when the frequency modulation income is not considered

the system's yield is only 6.0%

but it can be increased to 8.0% after considering the frequency modulation income. Therefore

the hybrid system has double effects in improvement of both coal saving transformation and flexibility transformation.