Research On Characteristics Of Whole Thermoelectric Generator With Integrated Muffler And Catalytic Converter

About 40% of the power output of traditional cars enters the atmosphere during the exhaust stroke.Thermoelectric generation technology is very suitable for the recovery and utilization of automobile exhaust waste heat.It is of great significance to improve energy utilization and reduce pollutant emission.Adding thermoelectric generators to the exhaust system will affect the muffler performance and catalytic conversion performance of the original system.Therefore,an integrated automobile exhaust thermoelectric generator integrating muffler and catalytic converter is proposed in this thesis,establishes an acoustic thermal fluid multi physical field coupling model,and carries out the numerical simulation of the flow field distribution,muffler performance and catalytic conversion performance of the integrated thermoelectric generator.On the basis of ensuring the performance of the exhaust system,improve the performance of thermoelectric generation and improve the economy of the whole vehicle.The basic structural units affecting the performance of muffler and catalytic converter are numerically simulated and analyzed by using Fluent and Actran,which establishes the foundation for the structural scheme of integrated thermoelectric generator.The results show that in order to improve the muffler performance and reduce the exhaust pressure loss,the length of the inlet perforated pipe should be slightly less than that of the outlet perforated pipe,and the diameter of the perforated pipe should not be too large,The opening rate shall be increased appropriately,The diameter and shape of the perforated tube have little effect on the muffler performance;The use of sound-absorbing materials will increase the loss of exhaust pressure.In the aspect of catalytic converter,it focuses on the influence of structure on carrier speed uniformity and exhaust pressure loss.The results show that in order to improve the catalytic conversion efficiency,a baffle should be arranged in front of the catalytic converter carrier to make the automobile exhaust diffuse evenly and enter the carrier.Based on the structural analysis of muffler and catalytic converter,the integrated design of thermoelectric generator,muffler and catalytic converter is carried out.Adjust the layout position of the perforated pipe and catalytic converter carrier in the integrated thermoelectric generator to form scheme A when the carrier is in the middle of the model and scheme B when the carrier is in the outlet of the model.The thermoelectric generation performance,muffler performance,catalytic conversion efficiency and exhaust pressure loss of the integrated thermoelectric generator are simulated and analyzed.The results show that the position of the perforated tube affects the utilization of the heat of the tail gas by the thermoelectric generator.In terms of layout,the perforated tube should make the tail gas fully diffuse at the inlet of the integrated thermoelectric generator and improve the performance of thermoelectric generation.In order to make use of the heat released from the catalytic conversion reaction in the carrier,the carrier should be far away from the outlet of the integrated thermoelectric generator,and a baffle should be arranged in front of the carrier.The evaluation results show that the thermoelectric generation performance and speed uniformity of scheme A are better than scheme B,and their muffler performance is similar,but the exhaust pressure loss of scheme A is too large.Further analysis shows that on the basis of the structure of scheme A,change the opening mode of the front baffle of the carrier,reduce the opening quantity at the tail end of the inlet perforated pipe and the diameter of the rear baffle of the carrier.The thermoelectric generation performance and muffler performance of the optimized scheme are basically unchanged,the exhaust pressure loss is reduced and the catalytic conversion efficiency is improved.Based on the analysis of the performance of the original exhaust system,an integrated thermoelectric generator is integrated in this thesis.Compared with the original exhaust system,the muffler performance,exhaust pressure loss and catalytic conversion efficiency are optimized.At the same time,the thermoelectric generation performance is improved and the economy of the whole vehicle is improved.