Calculation of efficiency and power output by considering different realistic prospects for recovering heat from automobile using thermoelectric generator

The development of a method to calculate the efficiency and the methodology to enhance the efficiency is not the ultimate goal. Mainly, the calculated results obtained by using a mathematical relationship and a physical law should be applied in day to day life applications for the benefit of society. In this work, we have developed the theoretical prototype and improved the technique for installing the thermoelectric generator (TEG) setup in automobiles. We have applied the methodology for enhancement in the efficiency of TEG and made it economical and user friendly. We have considered a linear curve fit from a zigzag curve of the reported mass flow rate and temperature variation at the hot gas inlet. Accordingly, the temperature of the coolant is also varied linearly at the inlet from 300K to 320 K, corresponding to the mass flow rate of the coolant. Circular fins are installed around each circular layer of thermoelectric materials (TEMs) after the water jacket. The heat loss through each fin is calculated to be 24W. The energy balance is done at each and every TEM, and correspondingly, we have calculated the amount of power transferred through each segment of TEG as 32W. We have calculated the length of the TEM sample for attaining the respective temperature range for the hybrid of Bi2Te3 and TiO1.1. This calculation is done by considering the compatibility factor derived as s = root 1+ZT-1/alpha 1, which is a function of only intrinsic material properties and temperature, which is represented by a ratio of current density to conduction heat flux. The length obtained for this particular combination is similar to 8mm. To this end, we have reported the efficiency with respect to the mass flow rate of hot flue gas from automobiles for different layers of TEG for the above mentioned combination. Here, we have explored the possibility of installing a number of different layers of the TEG module which can be installed throughout the lateral surface area of the exhaust chamber. Thermal mismatching criteria are also discussed at the adjoining surface of TEMs because of high temperature. To maintain the thermal expansion or contraction of TEMs, spring and bolt arrangement is provided, which is fixed over the aluminium oxide ceramic substrate. Ideal power output by the first layer is also calculated using a temperature dependent material parameter, which is 100W and plotted in a graph showing the change in power output with a variation in the temperature of sink. For automobiles, if the temperature of the source is considered as 800K, so for the temperature range of 300K to 800K, the power obtained is 58W. Published by AIP Publishing.