Analysis Of Fluoroplastic Finned Tube Heat Exchanger's Heat Transfer Performance Based On Flue Gas Waste Heat Recovery

With the rapid development of the economy,the total energy consumption continues to rise,but China's overall energy utilization level is only about 33% and lower than the world average level.Industrial waste heat recovery has become an important part of promoting energy conservation and emission reduction in China.China's total waste heat resources account for 17% ? 67% of the total fuel consumption,and the renewable waste heat energy is about 60% of the total waste heat resources.Compared with metal finned tube heat exchanger,fluoroplastic finned tube heat exchanger is widely used because of it's corrosion resistance,high heat transfer efficiency,long service life and difficulty in scaling.In view of this,this paper combined with the actual Beijing company of fluorine plastic structure size of finned tube heat exchanger and the existing natural gas waste heat recovery boiler actual test running parameters.Through CFD software for the operating mode of fluorine plastic finned tube heat exchanger has carried on the modeling work,and use the actual operation parameters to define the boundary of the work.Using the Fluent software to simulate the finned tube heat exchanger,in turn define turbulence model,the solving environment and using second-order windward.The velocity field,temperature field and pressure field of flue gas in natural gas boiler are obtained by solving.By comparing the simulated value of the flow field with the measured value,the relative error of the overall pressure drop is about 7.53%,and the relative error of the outlet temperature is about 3.78%.The numerical simulation method can clearly reflect the operation of the finned tube.The effects of Reynolds number,fin spacing and thickness,and flue gas inlet velocity on heat transfer performance were analyzed.The results show that with the increase of the flue gas inlet velocity,the Nusselt number and the average heat transfer coefficient increase,so that the heat transfer effect is strengthened,and the corresponding air pressure drop also increases,and the energy consumed by the fan also increases.The decrease of fin spacing enhances the heat transfer effect,and the drag coefficient decreases gradually.Finally,the heat transfer performance of heat exchangers with different parameters was analyzed by using the comprehensive evaluation factor of enhanced heat transfer performance.