To increase the efficiency of a thermal power plant, there had been several processes for recovering exhaust gas heat at the boiler cold - end with an integration of the steam turbine heat regenerative system. However, the existing processes for this purpose encounter a great challenge on the heat exchanger, in which acid corrosion, fouling, and abrasion to heating surfaces are inevitable as the surface is exposed to the flue gas in very low temperature. To avoid these tricky problems, a novel hot - air recirculation (HAR) process, in which clean air is used as a heat transfer medium for exhaust heat recovery while a condensate air heater is integrated into it for a more efficient power generation, is proposed and analyzed in this paper. To demonstrate the thermo - and techno - economic performance of HAR, an in - service 600 - MW hard coal - fired power unit was used as a reference unit for analyses. Meanwhile, the performance of the conventional bypass flue process was also calculated for comparison. The results show that, when recovering the boiler exhaust heat from 122 degrees C to 90 degrees C, the net coal savings, initial capital cost, and payoff period of the HAR are 3.49 g/(kW center dot h), $1.473 million, and 1.34 years, whereas the corresponding results of the conventional bypass flue are 2.98 g/(kW center dot h), $2.528 million, and 3.04 years. Overall, the HAR can benefit the power plant with a safe and reliable operation, greater energy savings, and a better techno - economic performance, exhibiting an obvious superiority in similar processes.