Development of a Spreadsheet to Model Releases from Continuous Volume Sources

摘要

Atmospheric dispersion models are used to estimate the downwind concentration of pollutants emitted from industrial sources. Air quality dispersion modeling has been evolving rapidly in the United States since the passage of the Clean Air Act of 1970. Over the last three decades, stringent environmental regulations and the accessibility of personal computers have fueled an enormous growth in the use of mathematical models to meet the requirements of different air quality regulations. The air quality models for point and area sources are well developed. However, the current model for volume sources used in the Industrial Source Complex (ISC) model and the AERMOD model are approximate solutions of dispersion equations. Volume source releases emanate from a three-dimensional volume such as a box and are encountered in many industrial plants. Examples include releases from conveyor belts or the collective releases from the gas pumps at service stations. The volume source model is also used to simulate the effects of emissions from sources such as building roof monitors and line sources (such as conveyor belts and rail lines). There are two types of volume sources: surface-based sources, which may also be modeled as area sources, and elevated sources. An example of a surface-based source is a surface rail line. The effective emission height for a surface-based source is usually set equal to zero. An example of an elevated source is an elevated rail line with an effective emission height set equal to the height of the rail line.