FIELD: power plants burning fossil fuel. SUBSTANCE: method involves heating of air supplied for fuel combustion and transfer of some portion of heat contained in stack gases and/or in heated air to bypass line for air supply to process medium. For further raising power plant efficiency, air supplied for fuel combustion is heated before admitting it to air heater by means of low-pressure process medium; so, heat applied to air meant for fuel combustion is extracted from stack gas passed through bypass line to air heater or from circulating air used for fuel combustion so as to heat up process medium held at higher pressure. EFFECT: facilitated procedure. 5 cl, 1 dwg
