What software can be used to analyze the integration of smoke towers?

Combining the smoke tower and the tower? ? Are they chimneys and spray absorption towers? ?

The smoke tower integration technology combines the chimney and cooling tower of a thermal power plant into one unit; by eliminating the chimney, the large volume of hot and humid air from the cooling tower is used to create an annular air curtain around the desulfurized exhaust gas. This curtain wraps around and lifts the desulfurized exhaust gas, increasing its elevation and thereby facilitating the dispersion of pollutants in the exhaust gas. By adopting this technology, it is possible to improve the energy utilization efficiency of thermal power generation systems; moreover, it **simplifies the flue gas system in thermal power plants, reducing equipment investment and the operating and maintenance costs of desulfurization systems. This technology has been applied at Huaneng Beijing Thermal Power Plant.

The smoke tower integrated process system generally has two types of emission methods: external and internal. 1.1 External type: The desulfurization unit is installed outside the cooling tower, and the clean flue gas after desulfurization is introduced into the cooling tower for emission. 　　The desulfurization unit is installed outside the cooling tower; the clean flue gas is directed directly to the upper part of the spray layer in the cooling tower, where it is demisted by a mist remover installed inside the tower before being released evenly, without coming into contact with the cooling water. In foreign countries, in the early days, when the desulfurization system malfunctioned, due to the relatively high temperature of the raw flue gas and the high sulfur dioxide content, it was not suitable to discharge it through cooling towers; instead, it had to be discharged through dry chimneys. At present, since the desulfurization unit operates stably, a bypass chimney is generally not installed outside the cooling tower. 1.2 Built-in type In recent years, the technology of integrating smoke stacks and cooling towers abroad has continued to develop, with a trend toward installing desulfurization devices within the cooling towers. It makes the layout more compact and saves space. The flue gas after desulfurization is discharged directly from the top of the cooling tower. By eliminating the chimney and flue gas heat exchanger, less land is required, which **reduces the initial investment and saves on operating and maintenance costs. 　　The following describes the built-in smoke tower integration process technology. 2 The impact of the smoke-tower integration technology on flue gas From an environmental protection perspective, the fundamental difference between flue gas emission from cooling towers and that from chimneys lies in: a. The different temperatures of the flue gas or flue gas mixture. 　　b. The discharge rates of the mixtures are different. 　　c. The initial concentrations at the mixture point are different.

Theoretical analysis of flue gas lift height: The purified flue gas discharged from the tower has a temperature of around 50 °C, which is higher than the temperature of the wet air inside the tower; as a result, mixing and heat exchange occur, and this mixing alters the gas flow conditions within the tower. Since the density of the flue gas entering the tower is lower than that of the air inside the tower, it has a positive effect on the thermal buoyancy of the air in the cooling tower. Furthermore, the flue gas entering the cooling tower is very small in volume, accounting for less than 10% of the air volume inside the cooling tower. Therefore, the flue gas can be discharged smoothly through the natural cooling tower. The emission of flue gas has a positive effect on factors such as the uplift and velocity of the air inside the tower. 　　Near the emission source, the rise of flue gas is less affected by environmental turbulence. When the temperature layers in the atmosphere are not very stable, the rise path of smoke is primarily influenced by its own turbulence, and is determined by factors such as the buoyant flux of the smoke, its momentum flux, and the wind speed in the environment. This period lasts from several dozen seconds to over a hundred seconds, during which the rising path of the smoke takes on a curved shape. As the flue gas rises, it continuously draws in ambient air due to its own turbulence. As the flue gas is continuously drawn into the ambient air with negative buoyancy, and at the same time suppressed by the positive potential temperature gradient in the environment, its upward trajectory gradually flattens until its ascent comes to an end [1]. 　　Wet flue gas also follows the aforementioned upward movement pattern; the difference is that as saturated wet flue gas rises, water vapor condenses due to the decrease in pressure and the reduction in saturated specific humidity. The condensation of water vapor releases latent heat of condensation, which raises the temperature of the wet flue gas and increases its buoyancy. In an unsaturated environment, only a small portion of the water vapor in the wet flue gas condenses; the latent heat released by this condensation does not result in a significant increase in the buoyancy of the flue gas. However, when saturated wet flue gas rises into a saturated atmospheric environment, this release of latent heat significantly alters the lift height, which increases by a factor of two. Figure 2 shows a comparison of the lift heights of dry and wet flue gas; it can be seen that the lift height of flue gas with the same volume is equivalent to that of dry flue gas after being heated by several dozen degrees. Flue gas desulfurization: Technical advantages of integrating the flue tower and cooling tower. At present, the height of chimneys in large thermal power plants in China is generally between 180 and 240 meters, while the height of cooling towers ranges from 110 to 150 meters, resulting in a significant difference in heights. Under the same conditions, the rise of wet flue gas is higher than that of dry flue gas. Analysis of actual lift height: The flue gas volume from the cooling tower is about 10 times that of the chimney, resulting in a high heat release rate. Relatively speaking, the heat carried away by the turbine exhaust through cooling water accounts for about 50% of the total heat loss in the plant (based on heat efficiency), while the heat carried away by the flue gas at the back of the turbine accounts for only about 5%. Although the temperature of the flue gas from the cooling towers is low, the high heat release rate of water vapor compensates for the lower height of these cooling towers; as a result, the actual elevation of the exhaust gas from the cooling towers is not lower than that of chimneys mounted at higher heights. This is the situation under conditions of unsaturated environmental humidity. When the environment is at saturation, the plume rise height of the cooling tower will be **higher than that of chimney exhaust. The results of flue gas plume rise measured by German scientists at the Volklingen test power plant also confirmed that the plume rise height from cooling tower exhaust is higher than that from chimney exhaust.

Ground-level concentration of SO2: Figure 4 shows a comparison of the annual average ground-level concentrations of pollutants emitted from the cooling towers and chimneys of a power plant in Germany. As can be seen from the figure, the ground-level concentration of the pollutant SO2 is roughly the same for emissions from tall chimneys and low cooling towers. 　　It is worth noting that sometimes the atmospheric boundary layer is essentially near-neutral, but there is one or several layers that are inverted. Under inversion conditions, vertical exchange in the lower layers of the atmosphere is hindered; if such exchange were to occur, energy would be required. When the flue gas from power plants has high energy and significant buoyancy, it can pass through the inversion layer relatively easily. If all of the flue gas manages to penetrate the inversion layer, it will not return to the lower layers, thereby avoiding pollution of the ground. If the buoyancy of the smoke is not sufficient to penetrate the inversion layer, it remains trapped below that layer, resulting in more severe pollution. Since the mixed flue gas emitted by the smoke tower integration technology contains a large amount of water vapor, and the heat contained in this water vapor exceeds the heat carried away by the flue gas in the air, it possesses significant buoyancy; as a result, exchange between the upper and lower layers is possible. Therefore, in poor weather conditions, using a cooling tower for smoke exhaust is better than using a chimney. The impact of different types of cooling towers on the concentration of SO2 at ground level. When desulfurized flue gas is emitted from cooling towers, these towers can be regarded as a point source of emission. If the height of the cooling tower and the diameter of its outlet affect the concentration of the flue gas at ground level, then the selection of these parameters should not be based solely on cooling considerations; rather, the best options must also be determined from an environmental protection perspective. 　　H. Damjakob and others in Germany studied variants of cooling towers. The ground concentration of pollutants from the variant tower was observed. Studying variant towers involves modifying the geometry of a selected baseline cooling tower and observing its specific thermal performance data. All cooling towers were studied under the following assumptions: under the same head, water with the same flow rate is cooled from the same hot water temperature to the same cold water temperature. The base cooling tower has a height of 140 m, and its base diameter is approximately 57.5 m; it was designed for a steam-driven heating unit with a capacity of 590 MW. The flow rate of the cooling water is 12,300 kg/s. At an atmospheric temperature of 10 ℃, a wet-bulb temperature of 8 ℃, and an atmospheric pressure of 101.3 kPa, the temperature of the cooling water is 18 ℃, and it is sufficient to cool a 550 MW generator set, whose exhaust gases are discharged through the cooling tower.

From the above analysis, it can be seen that if the smoke tower and cooling tower are integrated, conventional cooling towers should not be used alone; by appropriately increasing the height of the cooling tower and altering its diameter ratio, it is possible to more effectively reduce the concentration of air pollutants at the ground level. Optimizing the design of conventional cooling towers brings significant environmental benefits.