Design Of Boiler Economizer And Simulation Of Folw Field About Uniformity

With the deepening of government’s reform about energy, the utilization of waste heat, especially the rear of boiler flue gas flues, had drawn increasing attention recently. The introduction of low-temperature economizer greatly enhanced the heat transfer efficiency of the boiler, but there are some attendant issues that need researchers to pay attention to. Hence, a reasonable set of low-temperature economizer required an improved scheme to improve the uniformity of the flow field according to its actual deviation of fluid flow. Therefore, a more generally applicable low-temperature economizer can not only reduce the wear, but also prevent flue from burst causing by wear, what mean a lot to the plant which value safe as well as economy.Based on an actual project from ECEPDI, after a comprehensive understanding of waste heat utilization equipment such as low-temperature economizer, this paper designed a low-temperature economizer and an air pre-heater according to the Design Manual, and established the numerical model of the flue which were before the low-temperature economizer or after the air pre-heater and before the dust collector, by using Computational Fluid Dynamics methods. Even though both model paid attention to the velocity field for different flue structures, different parameters of fluid flow or different equalization arrangements, and achieved the optimized scheme to ameliorate the uniformity of flow field, the former model focus on curved flues, while the later one concern more about bifurcation. Both sections can realize the optimization of plant.By calculation to obtainreasonable parameters of the low-temperature economizer and air pre-heater, this paper analyzed the models that based on these parameters to find the potential weakness. The former model installed two sets of baffles to adjust the uniformity of flow field in curved or extend flues. However the later model regulated the shape, curve’s angle and radius of flues to achieve the aim. By adjusting the various factors within the program, can achieve good uniformity of the overall improvement in the flow field around the low-temperature economizer, to ensure that waste heat were taken good use of, and keep each device running efficiently. Meanwhile, this paper also has done work for the economic optimization of the power plant. In general, this paper provided a theoretical support and numerical reference for the relevant researches about the flow field around the low-temperature economizer.