Study On Heat Transfer Characteristics And Regulation Of Low-temperature Flue Gas Denitrification With Cyclonic Fluidization Reactor

In addition to coal-fired power plants,non-power industries such as steel,cement,and coking also emit relatively low-temperature flue gas.It contains harmful nitrogen oxides,which can have a significant impact on the environment and human health.To address this issue,lowtemperature flue gas denitration technology(60～200℃)has been developed to remove nitrogen oxides from non-power industry systems.This technology has important environmental and economic benefits,as it allows for the efficient removal of nitrogen oxides without the need for excessive heating or energy consumption.This paper presents experimental research,sophisticated detection methods,and mature computer simulation techniques to investigate the heat transfer characteristics of low-temperature flue gas and catalyst particles in cyclone fluidization reactors.The research is guided by the development of fluid-structure interaction heat transfer theory,turbulence theory,and computer fluid mechanics theory.The optimal structure and operating parameters of the cyclone fluidization reactor are designed and optimized based on the research results.The key findings of this study are as follows:(1)The residence time and retention mass of catalyst particles in the swirl fluidization reactor decrease as the apparent gas velocity and particle feeding speed increase.At catalyst particle feeding rates of 4.8 g/s,4.8 g/s,and 14.8 g/s,the minimum inlet gas velocities in the transport state were 3.5 m/s,3.90 m/s,and 4.02 m/s,respectively.As the feed rate of catalyst particles increases from 4.8 g/s to 14.8 g/s,the average residence mass of the corresponding catalyst particles in the cyclone fluidization reactor increases from 14.79 g to 40.62 g,and the average residence time decreases from 3.66 s to 2.915 s.(2)The heat exchange rate of catalyst particles increases with the inlet gas velocity,but decreases with increasing catalyst particle feeding rate.The energy-saving efficiency of the swirl fluidization reactor increases with the mandrel height,but the effect of mandrel height on energy-saving efficiency is minimal.The energy-saving efficiency increases with the inlet gas velocity,with a greater impact on energy-saving efficiency than the feed rate.The energy-saving efficiency decreases with the increase of the feed rate,with the feed rate having the greatest impact on energy-saving efficiency.Therefore,at low inlet gas velocities,a catalyst feeding rate of 14.8 g/s can reduce the airspeed of the swirl fluidization reactor and save energy by about 15%.