The main objective is to analyse the dispersion of gases emitted under different conditions of mass flow rate at the exit and ambient crossflow velocity by using software ANSYS. Main focus id to find out whether designed boiler stack can disperse atmospheric pollutants away from city or surroundings where the boiler is installed. Dispersion modelling includes means of calculating ambient ground level concentrations of emitted substances, considering the information like meteor ological data, pollutants flow rates and terrain data of area. This modelling is done to assess that the Ground level concentrations (GLC) of atmospheric pollutants owing to emissions from boiler stack are less than applicable ambient air quality standard
