Review of Exhaust Gas Heat Recovery Mechanism for Internal Combustion Engine Using Thermoelectric Principle

Automotive power packs have been the focus of research over a long period of time. Among various power packs when we consider internal combustion engines, there is an ample opportunity in developing systems that can make optimal utilization of all the energy streams related to the automotive engine. In this regard utilization of internal combustion engine exhaust waste heat and environmental pollution have been the focus of research in the recent past. About 35% of the automotive input fuel energy is converted to useful crankshaft work and about 30% energy is expelled with exhaust. This leaves about one-third (35%) of the total energy that must be transmitted from the enclosed cylinder through the cylinder walls and head to the surrounding. The exhausted energy from engine results in entropy elevation and solemn environmental pollution. So it is desired to utilize waste heat to the extent possible. The recuperation and utilization of waste heat not only conserves fuel but also additionally reduce the amount of waste heat and greenhouse gases dumped into environment. The objective of this study is to suggest waste heat recovery methods using thermoelectric generator which can be used to power various low energy consumption accessories of an automotive system. Thermo-electric generators are capable of enhancing the thermal efficiency of engines and can utilize the 35% of the exhaust gas stream energy efficiently.