Study On Structure Optimization Of Heat Exchanger And Heat Transfer Enhancement By Internal Flow Field In Segmented Asymptotic Thermal Power Generation System

The annual growth of car ownership has led to the gradual increase of global energy consumption,energy shortage and environmental pollution and other issues have attracted social attention,energy conservation and emission reduction has been the theme of The Times.Temperature difference power generation technology can effectively convert heat energy into electricity,and the conversion process is pollutionfree and emission free.Currently,temperature difference power generation equipment is mature and has been widely used in the industrial field.In the automobile industry,temperature difference power generation device is installed in the chassis of the automobile,which is used to recover the exhaust heat to generate electricity for the automobile,improve the energy efficiency and reduce energy consumption.The improvement of the structure of heat exchanger is an effective way to improve the efficiency of the power generation system.In this paper,a kind of structure of heat exchanger is proposed and improved.Firstly,the relevant theories of thermoelectric power generation system are introduced.The model and structure processing of flat-plate thermoelectric power generation device are carried out on the ANSYS/FLUENT platform,and the corresponding boundary conditions are set for grid independence verification.The errors are analyzed combined with the system efficiency,and the grid model suitable for the structure of this paper is selected.Secondly,three operating conditions are selected to simulate the traditional flatplate thermoelectric power plant.Taking the flat-plate thermo generator as the research object,the left and right walls of the heat exchanger gradually shrink inward along the tail gas flow direction.The simulation results show that the efficiency of the structure is increased by 18.45% compared with the traditional structure when the shrinking Angle is 6° at high speed.The system power can be further increased by 14.64% by changing the arrangement of the thermal power module on the surface of the heat exchanger and placing it towards the edge of the heat exchanger.Based on this,this paper proposes a thermal power generation device with the left and right sides of the heat exchanger gradually shrinking.Under the condition of medium speed and the shrinking Angle of 6°,the system performance is improved most obviously,and the power is increased by 10.3% compared with the traditional structure.Through the experiment of the traditional structure and the data comparison with the simulation results,the reliability of the simulation in this paper is verified.Finally,in the medium speed condition,the internal flow field of the segmented gradual thermoelectric power plant with a gradual Angle of 6° is optimized.By arranging fins of different structures to change the gas flow state inside the heat exchanger,the influence of fin height,length,layout position and layout Angle on the system power is analyzed.Finally,the gradual fin structure is established.Compared with the traditional flat-plate thermoelectric generator,the net power of the system is increased by 89.26% and the thermoelectric conversion efficiency of the system is increased from 2.9% to 5.01%.