Застосування повітряного методу за¬побігання конденсатоутворенню в газовідвідних трактах котелень

The results of studies of the efficiency of use in the heat-recovery technologies of gas-fired heating and industrial boiler plants of the air method to prevent condensate formation in the gas exhaust ducts are presented. The boiler installations, equipped with hot-water heat-recovery exchangers, designed to heat the return heat-network water and other water are considered (for hot water system, technological use, water purification system and other consumers). The authors have researched heat and humidity state in chimneys of different types at used to reduce humidity and increase the temperature of exhaust-gases of dry and heated air from the air-heater of the boiler at different operating modes of boilers. Herewith, different modes of operation of the boilers during the heating period were considered with the values of the exhaust-gas temperature in the nominal mode of 160 and 200 °С and the temperature of the admixed air 150 and 250 °С. These values correspond to the practical range of variation of the parameters during the operation of the respective boilers. The main parameters of the corrosion protection systems for chimneys were determined under the conditions considered, which ensure the prevention of condensate formation in them while observing the regulatory regimes of operation of these chimneys. Namely, by the values of the obtained temperatures of the inner surface of the mouth of the chimney and the dew point of exhaust-gases were calculated necessary to prevent condensation formation of the proportion of mixing of heated air, depending on the temperature of the air. The comparative analysis of the effectiveness of the use of the considered method of anticorrosive protection of gas-exhaust ducts for heat-recovery plants for various purposes has been carried out. It is shown that the use of the method of mixing heated air in heat-recovery technologies of boilers prevents condensation formation in chimneys with different fractions of air in exhaust-gases. The value of this share depends on the mode of operation of the boiler, the purpose of recovered heat, the characteristics of the chimney and other factors.