In this paper,a system model of direct thermoelectric conversion applicable to project analysis is established,and the structure and mathematical description of the internal enhanced thermoelectric generator are presented.Moreover,the variation trends of convective heat transfer coefficient,temperature and pressure in the generator channel are obtained through the numerical calculation of convection heat transfer and resistance characteristics.The results are finally compared with those of the external thermoelectric generator.Numerical analyses show that the components set in the channel effectively improve the heat transfer area and convection heat transfer coefficient,and that the shape change of the channel cross section may result in lower flow resistance and pressure drop,thus enhancing the thermoelectric conversion properties.