Objective In order to analyze and compare the effects of different baffles on the temperature field pressure field and flow field of the heat exchanger and improve the heat transfer effect of the heat exchanger ANSYS FLUENT software was used to simulate the heat exchanger. Methods Based on the distributed energy system of an industrial park the numerical simulation of the vertical heat exchanger in the system was carried out and the structure of the heat exchanger was optimized according to the numerical simulation results. Results The smaller the opening angle of the baffle was the higher the air outlet temperature was. When the opening angle of the baffle decreased from 180° to 30° the air outlet temperature increased by 11. 82%. At the same time the air velocity at the outlet of the heat exchanger increased significantly resulting in a greater impact on the outer cylinder. The smaller the baffle spacing was the higher the air outlet temperature was. When the baffle spacing decreased from 220 mm to 110 mm the air outlet temperature was increased by 14. 99% the contact time between the flue gas and the air through the inner cylinder wall became shorter and the flue gas velocity increased significantly at the flue gas outlet. The smaller the opening area of the baffle the higher the air outlet temperature. When the outer diameter of the baffle increased from 2 170 mm to 2 770 mm the air outlet temperature increased by 9. 22%. Conclusion When optimizing the structure of the vertical heat exchanger the opening angle of the baffle should be appropriately reduced or the opening area of the baffle should be reduced and the spacing of the baffle should be reduced so that the air can be fully transferred inside the heat exchanger.