Optimized Ultra High Efficiency Filter for High-Efficiency Industrial Combustion Turbines

Abstract

For modern high efficiency aero-derivative combustion turbines there is an urgent need for ultra high efficiency inlet air filters with a low initial pressure drop. Often high efficiency filters are associated with high pressure drop (e.g. HEPA). In this paper, through a mathematical analysis and design optimization, a new type of ultra high efficiency (>97% for 0.3 μm diameter particle), high capacity, and low pressure drop (0.5” w.g. at face velocity of 500 fpm) combustion turbine filter, particularly suitable for applications in the urban environment is presented. In mathematical analysis, a closed form analytical solution from Navier-Stoke’s equation for air flow between filter pleat spacing with uniform mass addition and extraction is applied to each finite element along the pleat channel. The optimum pleat aspect ratio is obtained by combining the expressions for the axial pressure gradient for upstream channel with mass extraction, the axial pressure gradient for downstream channel with mass addition, and the filter media flow characteristics for finite elements along the filter pleat channel with varying wall flow rates.