Numerical Study On The Flow And Heat Transfer Characteristics Of Longitudinal Finned Tubes With Two Wings

Inner fin tube has the characteristics of high heat transfer efficiency,small volume,which is widely used in impetus,chemical industry,electric power,aerospace and other fields.At present,with the rapid development of science,technology and modern industry,energy consumption is increasing,and people have higher requirements on energy saving and emission reduction in the industrial process.Looking for heat exchangers with higher heat transfer rate,flow resistance and lower production cost has become the focus of continuous attention.Therefore,on the basis of the longitudinal finned tube,the longitudinal finned tube with two wings is designed in this paper,which further improves the heat transfer efficiency of the finned tube heat exchanger and broadens the application range.In this paper,a new type of bilateral fin longitudinal fin heat exchange tube with different structural parameters was taken as the research object,and the standard k-epsilon and loss turbulence model was determined as the simulation model.Compared with previous experimental data,the model was verified,and the numerical simulation result is 3.2% lower on average.On this basis,the flow and heat transfer of bilateral longitudinal fin heat exchange tube were analyzed by comparing the light tube and longitudinal fin tube.By changing the structural parameters of the longitudinal finned tube with bilateral wings,Fluent software was used to conduct numerical simulation and analysis for different working conditions.Based on the performance evaluation index of finned optimal design,the longitudinal finned tube with bilateral wings with different structural parameters was evaluated,and the significance of the structural parameters was analyzed,and the following conclusions were obtained.(1)When Re=1500,the distribution diagram of temperature field,velocity field and pressure field of hot air in the center of light tube,longitudinal finned tube and bilateral longitudinal finned tube is compared,and it is concluded that the heat transfer effect of bilateral longitudinal finned tube is better.(2)In the simulation range(air inlet velocity is 3m/s ~ 12m/s),the heat transfer of fins increases with the increase of the number of fins,thickness and length of side fins,and the pump work consumed also increases.When the opening Angle of the wing is 45°,the heat transfer is small and the pump work is the largest,but when the opening Angle of the wing is 75°,the heat transfer of the fin is the largest and the pump work consumed is small.(3)The order of influence on the flow and heat transfer of longitudinal fin tube on both wings is from high to low: number of fins M> length of side wings l> lateral wing opening Angle ?> fin thickness ?.(4)According to the comprehensive performance of flow and heat transfer,select the appropriate structural parameters and lateral wing opening Angle of longitudinal finned tube of bilateral wings: at a lower velocity(v<7.5m/s),select the thinner(delta <0.5mm)and shorter(l<3.5mm)lateral fins,and the lateral wing opening Angle is 30°;At a high velocity(v>7.5m/s),thicker(delta >0.5mm)and longer(l>3.5mm)lateral fins were selected,and the lateral wing opening Angle was 75°.