Research On Mechanism And Control Technology Of Packing Fouling In Wet Cooling Tower

Dripping packing is a critical component in a wet cooling tower where heat dissipation can reach more than half of the entire cooling tower system and the packing is equivalent to the "heart" of the cooling tower.Most of the wet cooling towers use staggered corrugated packing,but there is the problem of fouling.Severe fouling will affect the heat and mass transfer coefficient of the packing,and even affect the thermal performance of the cooling tower.China has made great progress in the research of cooling towers and packings,but there is almost no research on the fouling of packings in cooling towers.There have been preliminary studies on the composition,fouling mechanism,and how to prevent fouling of packing fouling in foreign countries.The specific descaling effect remains to be verified,and there is no analysis of the distribution law of fouling severity and the influence of fouling on heat and mass transfer.Therefore,it is necessary to further study the fouling problem of cooling towers.Scanning electron microscopy and energy spectrometer,X-ray fluorescence spectrometry,infrared spectrometer and other instruments were used to analyze the filling fouling of a power plant.It was found that the surface of the filler fouling was very rough,flocculate,with a large number of agglomerates and ellipses.The shape of the sheet-like structure,multi-component structure is intricate,filler PVC material and dirt boundaries clearly.The main elements contained in the dirt are O,Ca,C,Zr,Fe,Al,Mn,Si,etc.The main oxides are SiO2,CaO,Al2O3,Fe2O3,P2O5,MgO,K2O,MnO,SO3,etc.Chemical functional groups include OH bonds,carbonates,silicates,and the like.The main substances in the filler fouling are SiO2,silicate,carbonate(mainly calcium carbonate)Al2O3,Fe2O3,phosphate,Mg(OH)2,sulfate,and the like.This result is consistent with the results of the circulating water quality analysis.Utilizing FLUENT software,the UDM program was compiled to calculate the distribution of filler fouling through a filler fouling prediction model.The cloud distributions of particle fouling,chemical reaction fouling and crystallization fouling under windy and non-wind conditions were calculated,and the influence of wind speed on the scale of fouling and the distribution of fouling was also studied.Descaling technologies include mechanical cleaning and chemical cleaning.For filler fouling,the main method of mechanical cleaning is high-pressure water jet flushing,but the effect is general.Relatively speaking,the chemical cleaning's effect is better and the labor intensity is lower.Through each group of experiments to determine the best chemical cleaning agents and the corresponding optimal concentration,the optimal cleaning time.Based on this,it proposes methods for on-line descaling and shutdown descaling.