Acta Montanistica Slovaca (Dec 2006)
Concentration of NOX in the vicinity of the power plants Vojany EVO 1 and EVO 2
Abstract
The paper presents a calculation of the maximal concentration of nitrogen oxides in the vicinity of point sources (main chimneys) of power plants Vojany EVO1 and EVO2. The wind velocity u10,M (7), at which the concentration on a given place in the surrounding of the pollution source attains a maximal value, is calculated. The relation (8) for a calculation of the place with the maximal concentration for a given class of air stability (Table 1 and 2) and for a given wind velocity is derived. According to equation (3) and Table 3, a thermal capacity of EVO1 and EVO2 is calculated, considering a flat country in the vicinity of the sources (x3 = 0 in relation (1)). Subsequently, it is also considered that the wind direction has the direction joining the source and the place of concentration calculation (x2 = 0). The calculations of concentration are performed for the 5th class of air stability. As to this class, favourable conditions for the pollutants dispersion are there. Thus, the maximum concentration is in a relatively small distance from the source with a sharp concentration maximum. As to other classes of the air stability (Table 1 and 2), the maximum concentration is located in larger distances from the source, i.e. about 10 km, as it is considered in Table 4 and 5. The theoretical calculation of NOX concentration in the vicinity of the sources, EVO1 and EVO2, shows (Table 4 and 5) that it does not exceed the allowable limit of 150 µg.m-3.
