Optimization strategies to enhance waste heat recovery from engine coolant using thermoelectric devices

ABSTRACT

Engine coolants absorb almost 20% of the fuel’s energy as waste heat. An optimization strategy has been proposed in this study for the design of radiator of the vehicle equipped with TEG devices for maximizing energy conversion from waste heat. Cooling fin design of the radiator has been parametrically studied using computational methods. Additionally, the quantity of energy that might be recovered from the coolant has been approximated based on the experimental results of a large compression ignition engine. Effect of using additional radiators without cooling fans to increase energy extraction has been studied. Results have shown that the cooling fin design needs large modifications to incorporate TEGs on the radiator channels. It has been determined that a fin height of 6 mm and a pitch of 6.5 mm, in combination with the utilization of a base plate, provide the most optimal conditions for achieving maximum heat recovery and power generation. It has been noted that higher air flow rates and inlet coolant temperatures contribute to improved heat recovery and power generation. Estimates show that though the TEG efficiency is low, up to 5.14 kW of energy can be extracted from the coolant. Further, a 4.81 kW of energy can be extracted if an additional radiator is placed facing the airflow of the vehicle. Estimates show that up to 9.95 kW of power can be generated using the coolant heat alone on a 750 kW engine.

KEYWORDS:

• Thermoelectric generators
• coolant heat recovery
• radiator design
• fin optimization
• waste to energy

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Pramoj Sanker PS

Mr. Pramoj Sanker PS is a PhD research scholar in the Department of Aerospace Engineering at the Indian Institute of Technology, Madras, where he also obtained his Master's degree in Mechanical Engineering in the year 2009. He is currently engaged in researching heat recovery from engine coolant utilizing thermoelectric materials. His field of interest also encompasses adsorption colling, design of compact heat exchangers and internal combustion Engines.

Ravi Teja S

Dr. Ravi Teja S. serves as a postdoctoral fellow in the Department of Aerospace Engineering at the Indian Institute of Technology Madras. His research focuses on alternative fuels, combustion processes, and internal combustion engines.

Ramakrishna P A

Dr. Ramakrishna PA is a Professor in the Department of Aerospace Engineering at the Indian Institute of Technology, Madras. He earned his PhD (2003) and Master (1996) in Aerospace Engineering from the Indian Institute of Science, Bangalore. His primary research interests encompass aerospace propulsion, propellants, and high-pressure combustion. Dr. Ramakrishna has an impressive portfolio with 68 publications and 3 patents to his credit.

Sudarshan Kumar

Dr. Sudarshan Kumar is a Professor in the Department of Aerospace Engineering at the Indian Institute of Technology Bombay. He completed his PhD (2004) and Masters (2000) in Aerospace Engineering from the Indian Institute of Science, Bangalore. His research pursuits encompass experimental and computational investigations on flameless combustion of gaseous fuels, advanced aerothermochemistry, high-temperature air combustion, flameless/mild combustion, turbulent combustion, and modeling of combustion systems.