Exhaust flue gas heat recovery potential of heating boilers of buildings

Abstract

In this study, the heat recovery potential from the flue gases of the boiler in a central heating system building was investigated. The energy consumption of the building was calculated from Turkish Insulation Standard TS 825 for the example building for the four climate zone. Natural gas is used as fuel. Calculations have been made based on the outdoor temperature. The flue heat energy recovery potential of using natural gas in boilers changes depending on the dew point temperature of the flue gases. The excess air coefficient of the heating boilers is taken as 1.1 and 1.6 for natural gas. The flue gas temperature has been accepted as 150 and 200 0C. As a result, the energy potential of the flue gases, depending on the excess air coefficient and the temperatures of the flue gases, was investigated by using combustion equations. As a result, it was determined that the 50 0C change in the flue temperature was 53% and the 0.5 change in the excess air coefficient was 41% effective on the potential of heat energy recovered from the flue gas.