| Ammonia desulphurization technology has been widely used now, but thephenomenon of ammonia escape is very serious, especially for the single tower. Thereason for the formation of ammonia escape in ammonia desulfurization of the singletower was analyzed in this paper. It was pointed out that the flow field distribution ofabsorption tower and the performance of the demister had a great influence in theammonia escape. Based on the structure of the tower, the control scheme was proposed,and the optimization simulation on the fluid flow of absorption tower and demister wascarried out with CFD software in this paper.To solve the problems of uneven distribution of the airflow in the wet flue gasdesulfurization tower，a new-type inverted "V"-shaped airflow distribution boards wereproposed for airflow uniformly distributed. Numerical simulation of the airflow field,temperature field and pressure field in the desulfurization tower was carried out with theCFX software. Inverted "V"-shaped airflow distribution boards with different porositiesand no airflow distribution board in the desulfurization tower were simulated respectively.The results show that the airflow in the desulfurization tower without the airflowdistribution board were unevenly distributed, and the deflective flow in the tower wasobvious，which effects the Characteristics of demister and leads to ammonia escape. Wheninverted "V"-shaped airflow distribution boards was installed, the airflow distributioninside the tower was uniform. According to airflow distribution and pressure drop, theinverted "V" airflow distribution boards with porosity of50%were better than others.Besides, numerical simulation of the desulfurization tower with porous board was alsocarried out with the CFX software, and the results show the porous boards with porosity of30%and40%were better than porosity of20%. Compared with the porous plate, theinverted "V" shaped air distribution boards has advantages of airflow distribution, uneasyto fouling and small spraying impact force.To solve the low efficiency problems of the Wave-plate demister, a new type ofcosine plate demister was proposed. Numerical simulation results of the airflow field,pressure drop and efficiency in the state of five different bending width including30mm、40mm、50mm、60mm、70mm were compared and analyzed. The efficiency was better when the bending width demister was50mm. To further improve the demisting efficiencybased on this evidence, simulation-optimization was carried out when the length and theposition of hamulus was changed in the cosine plate demister, and a better structure of thecosine plate demister was gained. The simulation results show that the demistingefficiency could increased by4.5%compared with Wave-plate demister with theoptimized cosine plate demister in the same conditions. |
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