Performance of Water Cooled Thermoelectric Generator System for Petrol Engines Using Ćuk Converter

Thermoelectric Generators (TEGs) are popular nowadays for their application in waste heat recovery from automobiles. 75% of the energy extracted from petrol is wasted as heat in an automobile IC engine. This emitted heat contributes a major part in increasing global warming due to the increasing amount of automobiles day to day. In this paper, a part of the heat wasted from the exhaust of a two-stroke petrol engine is converted into electricity and is utilized to charge the battery. The main purpose of this energy extraction and conversion is to cut down the amount of heat released from the automobile exhaust into the surroundings and thus encourage conscious use of energy. But one of the challenges in this conversion is that the output voltage and efficiency of a thermoelectric generator module are low for charging the battery. To rectify this, a Ćuk converter is utilized to boost the voltage of the TEG module. MPPT algorithm controller is also implemented to ensure maximum power extraction from the module at all times. In this paper, an attempt is made to cool the cold side of TEG using water flow rather than airflow. It is observed that the temperature difference between the hot and cool sides of the TEG reduces when water is used as a coolant and this significantly reduces the power output from the TEG when compared with an air-cooled system. Water-cooled TEG system output voltage does not reach the expected value and cannot be used to charge the battery. The comparison between an air-cooled and water-cooled TEG system is also done.