Numerical Simulation Research On The Influencing Factors Affecting The Emission Of The Technology Of NOCT With Flue Gas Injection

Because of its obvious economic and technological advantages and the ability of reducing the flue gas pollution,the technology of natural draft cooling tower?NOCT?with flue gas injection is gradually paid attention to in the power plant industry.On the basis of the predecessors,the computational fluid dynamics software Fluent was used in this paper for numerical calculation about the three factors that affect the smoke emission of the technology,such as atmospheric wind speed,flue gas emission rate and flue gas emission temperature.At the same time,the economic and technical analysis of the technology of NOCT was carried out.The main contents and conclusions of this paper are as follows:?1?The value method of the vertical profile wind velocity u?Z?and vertical section air temperature??Z?was determined by exploring the mechanism of uplift and diffusion for the smoke plume and two factors—dynamic lifting and buoyancy lifting.At the same time,the mass,buoyancy and momentum conservation equations of the smoke plume were determined.?2?The numerical simulation model of the NOCT was established in this paper.The factor about atmospheric wind speed was numerically simulated and the conclusions were as follows.The larger the atmospheric wind speed was,the smaller the height of smoke plume would be.At the same time,when atmospheric wind velocities were2m/s,4m/s,8m/s,the peak ground concentrations of NO in the region of downwind direction were 86.5?g·m^-3,55.8?g·m^-3,19.7?g·m^-33 respectively.That meant with the increase of atmospheric wind velocity,the ground concentration of the main smoke plume pollutant NO decreased gradually,which was beneficial to the diffusion of the flue gas pollutants.?3?The factor about flue gas emission rate was numerically simulated and the conclusions were as follows.The larger the flue gas emission rate was,the larger the height of smoke plume would be.At the same time,when flue gas emission rates were 4.7m/s,8m/s,12m/s,the peak ground concentrations of NO in the region of downwind direction were 86.5?g·m^-3,76.1?g·m^-3,59.2?g·m^-33 respectively.At the same time,the distance about the peak ground concentration of NO from the smoke tower was also increased,which were 2500m,2800m and 3100m respectively.That meant with the increase of flue gas emission rate,the ground concentration of the main smoke plume pollutant NO decreased gradually,which was beneficial to the diffusion of the flue gas pollutants.?4?The factor about flue gas emission temperature was numerically simulated and the conclusions were as follows.The larger the flue gas emission temperature was,the larger the height of smoke plume would be.At the same time,when flue gas emission temperature were 30?,60?,120?,the peak ground concentration of NO in the region the downwind direction were 97.3?g·m^-3,86.5?g·m^-3,61?g·m^-3 respectively.At the same time,the distance about the peak ground concentration of NO from the smoke tower was also increased,which were 2200m,2500m and 2900m respectively.That meant with the increase of flue gas emission temperature,the ground concentration of the main smoke plume pollutant NO decreased gradually,which was beneficial to the diffusion of the flue gas pollutants.?5?Through the comparison and analysis of this paper,the technology of NOCT has obvious advantages over the technology of traditional thermal power plants,such as these aspects:equipment investment,operation and maintenance and technology.The technology of NOCT has obvious economic and technical advantages.