Development of Design Guideline for Smokestacks of Standalone Emergency Generators to Satisfy Sri Lankan Emission Standards

This study presents a development of guideline for smokestack design of standalone emergency generators to satisfy the emission standards. Standalone generators of 10 kW to 1 MW range were considered for the study. Governing parameters for dispersion of the plume and effect of stack design parameters were studied. The backpressure effect of the stack design was analysed to establish its effect on the generator efficiency, and it was modelled by adopting ASME standards. Dispersion of the plume was modelled using Lakeview AERMOD software and the simulation results were validated using measured data in Colombo Fort region. The effect of the fuel type, emission source location and weather conditions were analysed using dispersion simulations. Influence of the considered weather data is valid for 2 km radius from the measured point. The ground level concentration of SO₂ with stack height and the diameter was plotted and it was used in determining the stack design parameters considering surrounding conditions. A set of design curves were developed by combining the dispersion simulations and backpressure calculations to design the smokestack height and diameter for stand-alone generators. The developed curves can be used to design the smokestack height and diameter for standalone generators of 10 kW to 1 MW.