ความสำคัญ/ ที่มา :
The electricity that is directly produced from heat by Thermoelectric Generator(TEG) [1-2]. More than 70% of the global energy consumption is lost during the conversion process as waste heat , This wasted energy originates from numerous sources such as mining and smelting plants, factories, electricity generators, air-conditioning and lighting appliances, vehicles’ engines, pipelines, brakes and exhausts, and even the human body-. TEG are made of semiconducting materials that are called thermoelectric pairs. Each pair has two pins, where one of them is doped to be p-type and the other one is doped to be n-type- . One side of TEG receives heating as the hot side (Th: high temperature side), while the other side has low temperature (Tc: cold temperature side). This temperature difference (∆T) allows the generation of electricity . The open-circuit voltage generated by TEG (V) is calculated V=N ∆T -where N is the number of connected thermocouples, αAB is the Seebeck coefficients of the two joined materials A and B forming the thermocouple (αAB=αA−αB) . However, the best efficiency recorded for TEG (most attractive material and structure) is relatively low, being only 11% . Therefore, several studies on TEG efficiency enhancement have been carried out, which can be classified into two common concept approaches. First, by using new or modified cell materials and structures - such as Figure of merit and thermocouples arrangement, earth-abundant absorbers, and innovative devices - and TEG’s Type of structure, Vertical, planner and mixed. Second, providing high different temperatures between both sides of TEG - such as cooling pads, heatsinks, multi-stage modules and other cooling systems.
However, using of rare earth-abundant materials that allow for increased efficiency. But the cost of materials is more expensive as well and the maximum temperature difference of the two sides of TE is still limited by the material that means that the generation of voltage still has a limited in level.
In this research, the parabolic pulse heating to the most commonly used structure of TEG was examined and analyzed. The most effective temperature T in theory - in the range of 0-120oC was used. The output voltage levels of the device could be determined based on both theoretical and experimental verifications.