Thermodynamic analysis and techno-economic analysis are performed on a novel thermal system(modified power plant) for a 300 MW single reheat subcritical coal-fired power plant. In the modified power plant

all the flue gas from the air preheater is used to heat the partial condensate in flue gas-condensate preheater(FGCP)

air for combustion is preheated by extraction steam in steam-air preheaters(SAH)

which is arranged in series with the corresponding regenerative heater. In the FGCP

the flow rate of the condensate is adjusted to ensure that its heat-capacity flow rate is equivalent to that of the flue gas

thereby avoiding the pinch point of temperature difference in the conventional air preheater. The results show that the exit temperature of flue gas from boiler can be reduced to near the acid dew point of the flue gas without cold end corrosion and clog. And the power generation efficiency of the modified power plant can be improved by up to 45.29%

which is 1.14 percentage points higher than that of the conventional unit. The dynamic investment payback period of the modified power plant is about 4 years

which is feasible.