Simulation of Flow Field in an SCR Converter

SCR converters have been used in ships for several years and various types of SCR are available. Although an SCR is very effective for NO_x emission, due to progressively stricter emission regulations, the catalytic converter design and performance need to be continuously improved. The design improvement efforts require broadening of fundamental understanding of various physiochemical processes that occur in a catalytic converter. The complexity of modern systems and the resulting flow dynamics, thermal and chemical mechanisms have increased the difficulty in assessing and optimizing system operational performance. Due to overall complexity and increased costs associated with these factors, modeling and simulation continue to be pursued as a method of obtaining valuable information supporting the design and development process associated with SCR optimization. Detailed flow velocity, temperature and species concentrations in a catalyst are often difficult to measure experimentally, thus, simulation can provide additional information that may be unobtainable from other ways. In this paper, a theoretical investigation has been performed on the distribution of flow, uniformity index and pressure loss in a diesel engine catalyst converter. The numerical simulation of the flow field in a catalytic converter with different diffusers was carried out. The effects of different diffusers on the flow pattern, velocity distribution, uniformity index, temperature field, conversion efficiency and pressure loss in a catalytic converter were studied.