Experimental Study And Numberical Simulation Of A New Type Of Double-Fin Plate Air Preheater

This paper deals with a cast fin type air preheater for use in the chemical industry.This air preheater has some characteristics such as long service life,low resistance,easy installation,strong resistance to dew point corrosion and so on.In this paper,the thermal performance of the experimental piece is studied by experiment and numerical simulation,and the heat exchanger with different fin spacing is analyzed by numerical calculation.In this paper,the performance of the test piece is evaluated by the theory of entransy.The main results are as follows: 1,we constructed the air preheater experimental platform,and used equal velocity method to test the performance of the actual using conditions the air preheater.The results show that the heat transfer criterion of the test piece and the expression of the heat transfer factor j and the friction factor f are obtained by fitting the drawing method.2,the structure of the air preheater is analyzed,the numerical simulation heat transfer unit is confirmed,and the using condition of the heat transfer unit is researched by using CFD.The results show that the maximum error between experiment and CFD is not more than 10%.Numerical analysis of six sets of 10 mm to 20 mm fin spacing of the air preheater has been done.The simulation results show that,when the fin spacing is 10 mm,the heat exchanger has the strongest heat transfer performance,at the same time the resistance increases,but the pressure loss increases not so much.In guarantee of the air preheater being cast out,the air preheater should be optimized with 10 mm fin spacing.3.The relationship between the heat transfer heat resistance and the equivalent thermal resistance is analyzed by using the entransy theory.Through the analysis,the relationship between the effective unit number and the dimensionless equivalent thermal conductivity is obtained.In addition,by analyzing the experimental data,we obtained the experimental results of the effective unit number and the dimensionless equivalent thermal conductivity,and the entransy dissipation calculation formula.In this paper,the optimization scheme of variable fins around air preheater is also proposed.