Investigation of Effect of Dew Point Temperatures on Design of Condensing Heat Recovery Units According to Fuel Types

In this study, dew point temperatures of water and sulphuric acid vapour in flue gas are predicted as theoretical for fuels types such as coal, fuel oil, natural gas, LPG, wood with the different cities in Turkey. The factors like the excess air coefficient, relative humidity rate and the altitude of the city affected by the dew point temperatures and the mole ratios of water and sulphuric acid vapour in flue gas are studied. According to the results of the study, while the water dew point temperature changes for coal, wood, fuel oil, natural gas and LPG, over the range 30-40 degrees C, 40-50 degrees C, 37-50 degrees C, 44-60 degrees C and 41-56 degrees C, respectively; the acid dew point temperature waves to 125 degrees C from 140 degrees C for coal types and to 131 degrees C from 145 degrees C for fuel oil types in Turkey. To predict the condensing zone, a condensing economizer for a natural gas-fired boiler in a heating system is designed with Finite difference method. According to the results of the design, while the first 100 m of the heat exchanger tube is non-condensing zone, the only 10 m is the condensing zone.