Research On Automotive Exhaust-Based Thermoelectric Generator Energy Efficiency For Vehicular Application

As an energy conversion device,the thermoelectric generator converts the heat energy carried by the vehicle exhaust gas into electricity which can be stored for the use of the vehicle.Thermoelectric technology is one of the most promising means to recover the waste heat of internal combustion engine and it has great significance to improve the fuel economy of vehicles.When the thermoelectric generator is integrated into the vehicle,the thermoelectric generator consumes some energy while recovering the waste heat.In order to improve the fuel efficiency and reduce the fuel consumption,the thermoelectric generator energy efficiency for vehicular application is studied in this paper.And the relationship between the influence factors and the evaluation indexes of the thermoelectric generator energy efficiency is investigated.The thermoelectric generator with good comprehensive power generation performance is obtained by optimization design,which can effectively improve the automotive fuel economy.The paper is divided into four parts:Firstly,the output power and consumption power of the thermoelectric generator are studied.The system net output power,the single module average output power and the system efficiency are used as the evaluation indexes to evaluate the comprehensive power generation performance.On this basis,the energy efficiency calculation models of the thermoelectric generator are built,including the system output power calculation model,the system consumption power calculation model,and the system evaluation indexes calculation model.Secondly,the quasi-level orthogonal test scheme is designed,and the effects of the main influencing factors on the energy efficiency evaluation indexes of the thermoelectric generator are analyzed by using the numerical simulation model and the energy efficiency calculation models.The results show that the cross-section side length,exchanger length and module spacing are main influencing factors.The crosssection side length and module spacing are significant factors for the system net output power.The cross-section side length,exchanger length and module spacing are highly significant factors for the average output power of single module.The cross-section side length and exchanger length are highly significant factors for the thermoelectric system efficiency.Then,the main influencing factors of the thermoelectric generator are selected as the optimization design variables,and the evaluation indexes of system energy efficiency are selected as the optimization design objective.Furthermore,an approximate model of the thermoelectric generator energy efficiency is built with the elliptical basis neural network model.On this basis,by using multi-island genetic algorithm for multi-objective optimization,a thermoelectric generator with good comprehensive power generation performance is obtained.Finally,a simulation model which integrated the multi-objective optimized thermoelectric generator into the vehicle is built.In addition,an integration strategy is developed.When the target vehicle is fully loaded,the influence of the thermoelectric generator application on the automobile fuel economy is analyzed.The results show that the thermoelectric generator can effectively improve the automotive fuel economy.The study on the thermoelectric generator energy efficiency for vehicular application improves the automotive fuel economy.It provides a reference for the optimization design and vehicle integration of the thermoelectric generator,which has certain academic and engineering significance.