Empirical Estimation of Virtual Point Source Height Over a Bank of Coke Ovens

Abstract

This paper addresses an empirical method of assessment of the height of a virtual point source. In order to achieve such assessment, three planes defining the location of a virtual point source in a space are created and formulas describing the geometry of observer's sight and plume orientation are used. Data for calculations are obtained on a basis of plume photographs. The final position of a virtual emission point is described by a set of its coordinates in the Cartesian coordinate system. Presented method may be applied as a means to verify and validate the existing formulas describing the rise of plume above the stack exit or as a tool enabling acquisition of information for the sake of creating new formulas of this type. The calculation of the location of a virtual point source ascribed to the point emission from the roof of the bank of coke oven is presented and illustrated with photographs which reveal position of plume, adequate planes, axes and characteristic objects.

Inclusion of Increased Air Turbulence Caused by Coke Production into Atmospheric Propagation Modelling

“…The exemplary distribution shapes of these concentrations on measurement arcs are shown in the Also, the NMSE was calculated for the model with modified exponents and adjusted emission height ( _ Zeliński et al 2016). The NMSE value of 8.83 has been found.…”

“…In such models, the ability to generate mechanical turbulence by terrain surface is described by the surface roughness coefficient z0, while the power-law (or meteorological) exponent p constitutes a measure of both thermal and mechanical turbulences (El-Harbawi 2013;Saha 2008;Zanetti 1990). Parameterisation of the atmosphere due to thermal turbulence consists in determining atmospheric stability and introducing the right value of the exponent p into a model.…”

Validation of dispersion model designated for the coke production industry

“…As part of the model modification process, a few modules have been introduced. They take into account the following (Schulman & Scire, 1980 ): a larger rise in emitted plumes over the ground associated with considerable heat introduced into the air from technological sources (Żeliński et al, 2017 ), overlapping of plumes originating from several, closely located, neighboring sources which increases as well the height of virtual point of common emission, the mechanism of plume shear, which plays a particularly important role at low-altitude emission points, due to the strongly non-linear wind profile in such areas. It can influence the concentration due to locally weak air speed just over the ground surface, the phenomena occurring in the aerodynamic wake of buildings and other constructions, where the downwash usually causes the increase of concentration in close neighborhood of object body.…”

“…Increased air flow turbulence in such areas has been reflected both in computational simulations (Mirzaei & Carmeliet, 2013 ; Xie et al, 2013 ) and in measurements (Huq & Franzese, 2012 ), the plume rise height is increased due to higher buoyancy. This problem has been researched by many authors over many years, with the use of various methods: full-scale data analysis, wind tunnel experiments, and small-scale or numerical simulations (Briggs, 1984 ; Contini et al, 2011 ; Freitas et al, 2006 ; Kozarev et al, 2014 ; Żeliński et al, 2017 ). The observations made in these studies reveal a fundamental dependence between plume convection intensity and the temperature of outlet gases, this increased plume rise is often multiplied due to the merging of plumes from multiple sources, forcing an overall buoyancy enhancement which is characteristic of the several point emission points arranged in a line, especially when the wind direction is aligned with their long axis of symmetry.…”

“…the plume rise height is increased due to higher buoyancy. This problem has been researched by many authors over many years, with the use of various methods: full-scale data analysis, wind tunnel experiments, and small-scale or numerical simulations (Briggs, 1984 ; Contini et al, 2011 ; Freitas et al, 2006 ; Kozarev et al, 2014 ; Żeliński et al, 2017 ). The observations made in these studies reveal a fundamental dependence between plume convection intensity and the temperature of outlet gases,…”