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

Abstract

Development of method to calculate the efficiency and the methodology to enhance the efficiency is not the ultimate goal. Mainly the calculated result obtained by using mathematical relationship and physical law should be applied in day to day life applications for the benefit of society. In this work, we are developing the theoretical prototype and improving the technique for installing the Thermoelectric Generator (TEG) set up in automobiles. We have applied the methodology for enhancement in efficiency of TEG and make it economical and user friendly. We have considered a linear curve fit from a zigzag curve of reported mass flow rate and temperature variation at the hot gas inlet. Accordingly the temperature of the coolant is also varied linearly at inlet from 300 K to 320 K and corresponding the mass flow rate of coolant. Circular fin is installed around each circular layer of Thermoelectric Materials (TEM) after the water jacket. The heat loss through each fin is calculated as 24 W. Energy balance is done at each and every TEM and correspondingly calculated the amount of power transferred through each segment of TEG as 32 W. We have calculated the length of TEM sample for attaining the respective temperature range for the hybrid of Bi2T e3 and T iO1.1. This calculation is done by considering the compatibility factor derived as s = √1+ZT −1 αT which is a function of only intrinsic material properties and temperature and is represented by a ratio of current density to conduction heat flux. The length obtained for this particular combination is ∼8 mm. To this end, we have reported the efficiency with respect to mass flow rate of hot flue gas from automobile for different layers of TEG for the above mentioned combination. Here, we have explored the possibility of installing a number of different layers TEG module which can be installed throughout the lateral surface area of exhaust chamber. Thermal mismatching criteria are also discussed at the adjoining surface of TEM because of high temperature. To maintain the thermal expansion or contraction of TEM, spring and bolt arrangement is provided, which is fixed over the aluminium oxide ceramic substrate. Ideal power output by first layer is also calculated by temperature dependent materials parameter, which is 100 W and plotted in graph showing the change in power output with variation in temperature of sink. For automobile, if temperature of source is considered as 800 K, so for the temperature range of 300 K to 800 K is obtained as 58 W.

Water-Cooled Thermoelectric Generators for Improved Net Output Power: A Review

“…The most widely used geometry for water cooling is the conventional channel, due to its ease of fabrication. Water cooled channel was used in different applications, such as waste heat recovery of an air flow [22,23], of a water flow [24,25], of a hot surface, i.e., a CPU [26][27][28], of automobile exhaust gas [29][30][31][32][33][34][35][36][37][38][39][40] and of industrial production [41]. However, it also finds application in the utilization of primary energy such as combustion [42,43],…”

“…Energies 2021, 14, x FOR PEER REVIEW 5 of 31 waste heat recovery of an air flow [22,23], of a water flow [24,25], of a hot surface, i.e., a CPU [26][27][28], of automobile exhaust gas [29][30][31][32][33][34][35][36][37][38][39][40] and of industrial production [41]. However, it also finds application in the utilization of primary energy such as combustion [42,43], geothermal energy [44] and solar energy [45][46][47][48].…”

Thermoelectric properties, efficiency and thermal expansion of ZrNiSn half-Heusler by first-principles calculations

“…The calculated α(T ) gives a measure of the extent to which change in length occurs in the thermoelectric material. Thus, one can take into account this parameter when designing a TEG module or a hybrid TEG using segmentation of two materials 36 to reduce the possible stress and cracking due to thermal expansion.…”

“…Lesser value of this product indicates lesser thermal fatigue in that material. Thus, one can take into account this parameter when designing a TEG module or a hybrid TEG using segmentation of two materials [46] to reduce the possible stress and cracking due to thermal expansion at the interface.…”

Optimization of Hybridization Strategy for Improving the Efficiency of Thermoelectric Generator to Recover Automobile Exhaust Waste Heat

“…To improve the accuracy of ZT value, Gaurav et al [12,13] have introduced segmentation technique. In segmentation, the entire working temperature range is divided into the small segments.…”