Irradiance modeling in annular photoreactors using the finite-volume method

A computational radiation field model for simulating the irradiance in single-phase annular photoreactors was developed and evaluated experimentally. The developed model included the lamp within the computational domain allowing to incorporate important interactions between the UV radiation, the quartz walls, and the Hg vapor inside the lamp. Several lamp emission models were evaluated against far- and near-field experimental data. The models with diffused radiation emission showed better overall irradiance prediction capabilities. In particular, a modification of the extensive source volumetric emission model that incorporates the high photon absorbance/re-emission effect produced by the Hg vapor in the lamp illustrated superior results. This latter model showed excellent agreement with near- and far-field experimental data indicating its suitability for integration in multi-physics models for the simulation of photoreactor performance. The advantages of this model are: it is very easy to set up; it comprises the main physical phenomena occurring in the lamp; and it allows for taking into account important lamp-sleeve interactions. Experimental results reaffirmed the importance of applying proper estimates of the lamp power output under the actual operating conditions to perform accurate simulations of radiation distribution.