The pressure drop characteristics of humid air outside staggered tube bundles in the evaporative cooling process

Based on Euler-Lagrange method, a numerical model was established for the pressure drop characteristics of humid air outside staggered tube bundles (STB) during evaporative cooling in this paper. The influences of structural and operation parameters were analyzed for that. The results show that the pressure drop of humid air increases with the increase of mass flow rate of humid air and spray water, but it decreases with the increase of transverse and longitudinal distance. Meanwhile, the total pressure drop of humid air increases with the increase of tube diameter. It can also be found that the pressure drop in the transition area at the top of STB will increase with the STB height when the transverse distance is less than the minimum value (30 mm). Lastly, a new pressure drop correlation was proposed according to the CFD data. The error is less than 5% between the CFD results and the correlation results. The above conclusions will provide a theoretical basis for the research and selection of fan power in evaporative cooling heat exchangers.