A simplified mathematical model of a rotary regenerative air pre–heater (RRAP) is suggested and studied based on the averaged dynamics of the heat exchange process between nozzles and a heat carrier (i.e. air or gas–smoke mixture). Averaging in both spatial coordinates and time gives a linear discrete system that allows deriving explicit formulas for determining the characteristics of the air heater and establishing some properties such as periodicity, stability, ergodicity and others.This work was supported by Committee for Coordination Science and Technology Development Under Cabinet of Ministers of Uzbekistan (projectno F4–FA–F014).Authors express their gratitude to G.I.I bragimov for useful discussion and help
