Design Calculation And Numerical Simulation On Finned Tube Air Preheater

Under the background of increasingly severe energy problems and the situation of new normal energy development, the waste heat recovery and utilization in Chemical, petroleum, electric power, iron and steel, glass, cement, building materials, electronic aluminum and other energy industry is being taken more and more attention. As a key equipment in waste heat recovery, finned tube air preheater is widely used in the high energy consumption industries with its good heat transfer performance, compact structure, lightweight, high adaptability and other advantages. To achieve the waste heat recovery and utilization of high temperature flue gas is through convective heat transfer in a finned tube and the inner air, so it is important to study the velocity, temperature and pressure distribution of the flue gas side flow field of the air preheater, which has important theoretical guiding significance for the improvement of the efficiency of waste heat recovery and utilization.The object of this research is the preheating section about tar tube furnace in the base of Zhanjiang. According to the main parameters of design calculation and fin tube about air preheater, the important parameters for the structure, finned tube's number, the heat transfer area, the pressure loss of the heat exchanger is simplified. Geometric model of meshing is simplified through the processing software Gambit. In order to make out the fluid solid coupled heat transfer calculation, the fin tube need to be set into solid grid, and the flue gas basin need to be set into fluid grid. Using FLUENT software to make numerical simulation, the specific parameters of the calculated data are set as boundary conditions. Choosing appropriate turbulence model and control equation to calculate coupling field of velocity and pressure. Comparing the theoretical calculation and numerical simulation, the result shows that the relative error of outlet temperature is 9.3%, the relative error of the pressure drop is 7.4%, and the numerical simulation method can verify the feasibility of the design scheme of the fin tube air preheater.By comparing the flow field distribution characteristics in gas inlet velocity v=1.18m/s, 3.18m/s, 5.18m/s, 7.18m/s, an important conclusion was drawn, the bigger gas inlet velocity is, the smaller tailed flow area is. But the increasing of speed can't eliminate the wake region, it will also increase outlet temperature and pressure loss, fan load.