Study On Heat Transfer Performance Of Stainless Steel Ellipse Tube Heat Exchanger With Plate Fin

In this paper,a new type of stainless steel heat exchanger with elliptical tube sheet is studied.The influence of the structure of the silencer on the heat exchange and pressure drop is studied.The structure of the suitable silencer is selected,and the existing copper tube fin heat exchanger has some problems,such as poor corrosion resistance,high current resistance,high flow resistance and copper fouling.On the basis of volume,the heat transfer system of hot water heater is retrofit by stainless steel ribs with trapezoid ribs.The optimal structure is found by combining the experiment and numerical simulation,so as to reduce the cost of equipment and improve the heat exchange performance.This paper mainly studies the following aspects:1)The main influence of the theoretical analysis on the pressure drop of the pipe is the structure of the silencer.The heat transfer in the flue gas side is divided into radiant heat transfer and convective heat transfer,which is mainly convective heat transfer.Through theoretical analysis,the heat transfer ability can be improved by increasing the ribbed area and change the angle of the rib.2)Through the simplified model of the pipe side,a suitable three-dimensional physical model is established.The simulation results of the water pipe part show that the pressure drop has great influence on the pressure drop.The pressure drop continues to decrease with the increase of the gap between the silencer and the water pipe,but the heat transfer effect first increases and then decreases.When the gap between the silencer and the water pipe is0.0003 m,the heat transfer effect is strengthened and the pressure drop is reduced from 1074 Pa to 886 Pa.By simplifying the stainless steel sheet,a three-dimensional physical model of the single ribs and two rows of pipes is established.The simulation analysis of the parameters ofthe components of the flue gas is ensured.The simulation analysis of the angle,width and height of the different conditions and ribs is carried out.It is found that the heat transfer is mainly carried out in the first drain pipe and rib,and the efficiency of a row of ribs is more important than the efficiency of two rows of ribs.The fin structure is selected with the fin angle of 0 degrees,the width of 0.00438 m,the height of 0.015 m heat exchanger structure.The thermal efficiency is raised to 92.7%,and the two level energy efficiency standard stipulated in the national standard GB 6932-2015 is reached.The smoke exhaust temperature is reduced to 148.6,and the standard of non condensing water heater in the national standard GB6932-2015 is met.3)Compared with the simulated thermal efficiency and smoke exhaust temperature under the same working conditions,the results are analyzed and the thermal efficiency increases with the decrease of the load.The experimental data and simulation data are consistent,with an error of 7% and less than 10%,which proves that the simulation results are reliable.