Research on pressure loss calculation and determination of porous media resistance coefficients based on flow simulation of feed counterflow cooler

Abstract

In the feed industry, counterflow coolers are widely used cooling devices. The flow characteristics and pressure loss should be focused on during the design and optimization stages. Due to the complex accumulation of feed particles, it is difficult to accurately analyze the flow field behavior inside the cooler through experiments. Therefore, a detailed study was conducted with a cooler from Buhler using a simulation approach. First of all, the significant influence of the porous jump boundary of flap outlet in the simulation model on the flow field and temperature distribution was revealed. Second, limitations of the Ergun equation in estimating the drag coefficients of the porous medium and the porous jump boundary were explored. Finally, a rapid calculation model for pressure loss was established based on simulation data. Within a wide range of resistance coefficient inputs, the relative error between the model calculation and the corresponding simulation results is very small. Using this model to input a series of resistance coefficients, combined with a small number of overall pressure loss measurements for comparison, the resistance coefficient of the porous medium of the new material can be determined, solving the problem in determining this coefficient through typical measurement experiments at low flow velocity and the lack of effective estimation formulas. This research can provide practical references for improving cooling equipment and enhancing cooler efficiency, and the rapid calculation model can be extended to any fluid machinery containing porous media materials that satisfy Darcy–Forchheimer's law.