Experimental study on waste heat recovery system of an internal combustion engine using thermoelectric technology

• Published in: IOP Conference Series: Earth and Environmental Science
• Main Author: Suhaimi N.A.; Singh B.; Remeli M.F.
• Format: Conference paper
• Language: English
• Published: Institute of Physics Publishing 2020
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083428130&doi=10.1088%2f1755-1315%2f463%2f1%2f012141&partnerID=40&md5=8e4082932b7a3feff3b3e77224db1f2c

Internal combustion engines do not effectively convert energy from the chemical reaction into useful energy, notably mechanical energy. In fact, majority of the energy are converted into heat energy, and dissipated into environment which does not fully contribute to the performance of internal combustion engine. This results in lower overall efficiency of the engine. The heat released into the environment can be converted into useful electrical energy by using thermoelectric generator (TEG). TEG consists of cold side and hot side and works based on the principle of Seebeck effect. The hot side of TEG is exposed to hot surfaces of the exhaust, and the cold side is cooled with fan cooled heat sink. The function of heat sink is to increase the temperature differences across the TEG. The conversion of waste heat into electricity by TEG in an automobile can be a good case study to replace the alternator for battery charging and increase the overall efficiency of the Internal Combustion (IC) engine. In this study, eight pieces of TEG with dimensions of 40 mm x 40 mm each were attached to a square heat exchanger. This heat exchanger was connected to the exhaust pipe of the engine. The temperature recorded in the exhaust was more than 150 0C. Thermocuples were embedded on the hot side and cold side of the thermoelectric generators to evaluate the temperature differences across the TEGs. The output of the TEGs were obtained at idle and half-throttled engine conditions. An electronic load was applied to obtain the voltage, current and the power output from the TEGs system. The TEGs were tested individually, all connected in series and parallel connections. The maximum output voltage was recorded for the series connections at 5.8 V with an average hot side temperature of 48 0 C across TEGs. Maximum power output obtained when all the TEGs connected in series was at 2.3 W. © 2020 Institute of Physics Publishing. All rights reserved.