Emissionen aus Ölheizungen im stationären Betriebszustand. (2) Kleinfeuerungsanlagen bis 350 kW und Anlagen mittlerer Leistung bis 3 MW mit Heizöl Leicht

During the last three years the exhaust emissions of 299 boilers using light residual heating fuel were investigated in Austria during stationary operation phase. Light residual heating oil is a residual fuel with low viscosity, low sulphur and paraffin content and excellent cold weather quality. The plants were measured under as is conditions, i.e. at installed power, without readjustment and using the available heating fuel. Where possible, additional measurements were done using a testing fuel of defined quality. After service and adjustment of the heating plants the measurements were repeated with both heating oil qualities. The data of all these tests were analysed. In contrast to the plants fired with domestic heating fuel, with a large number of existing technologies, only one technological group could be found to be predominant in plants fired with light residual heating oil. This technology was the type of boiler without a hot combustion chamber in combination with a yellow flame burner. The emission factors for this group were calculated as 8 mg/MJ for CO, 115 mg/MJ for NOx and 1,3 for soot number. Within this technological group the emission values were independent ofage and power of the boiler to a high degree. Service and adjustment of the plants resulted in an improvement of the combustion parameters and in a reduction of emissions of up up to 90 %. The influence of the fuel on the level of emissions was very low.