Influence of conduction shape factor in subterranean cooling for a thermoelectric energy harvesting system at asphalt pavement: An experimental investigation

ABSTRACT

This research study’s primary motivation is to study the practicality and feasibility of energy harvesting or energy scavenging using ambient energy such as heat absorbed by asphalt pavement to provide electrical power for small electronic circuits or devices, making them self-sufficient. Therefore, this project investigates the thermal distribution evaluation of multiple diameters of the aluminum rod as a cooling element and examines the optimum designs for the surface heat absorption method using the aluminum plate in the road thermoelectric energy harvesting system (RTEHs). The RTEHs experimental setup consisted of an asphalt-filled wooden base box, “sandwiched” thermoelectric module, top aluminum plate, and bottom aluminum rod, which is partially submerged in the asphalt and soil. Using constructed RTEHs setup and several thermocouples, a series of experiments on multiple diameters of an aluminum rod as a cooling element and few aluminum plate designs were conducted to obtain the best configurations that yield maximum temperature difference between cooling and heating sides in asphalt based RTEHs. Based on the testing results, RTEHs with a mounted triple of Rod C, which has the biggest diameter of 31.75 mm (1.25 inch) and combined with 100 mm × 200 mm of a top plate, proved to be the best performing configuration by producing the highest temperature difference (DT) of 15.19°C. Since the triple rod configuration has a higher value of shape factor, this indicates a better heat transfer performance by conduction. These proved the theory of conduction shape factor for multiple geometries. Based on the results, having a bigger top plate as a heating element promotes a higher heat transfer rate and takes in more heat energy, thus producing the largest DT for the system, which confirmed Stephen-Boltzmann’s law on radiation heat transfer.

KEYWORDS:

• Conduction shape factor
• road thermoelectric energy harvesting
• pavement harvesting
• subterranean cooling
• thermoelectric application

Acknowledgments

This work was supported in part by the Ministry of Higher Education Malaysia and Universiti Teknikal Malaysia Melaka (grant number: FRGS/1/2017/TK07/FKEKK-CETRI/F00337).

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Additional information

Funding

This work was supported by the Kementerian Pendidikan Malaysia [FRGS/1/2017/TK07/FKEKK-CETRI/F00337].

Notes on contributors

Khairun Nisa Khamil

Khairun Nisa Khamil obtained her PhD degree in the field of Energy from Universiti Malaya.  Her research interests include Finite Element Analysis (COMSOL and ANSYS), Sensor technology (MEMS sensor and IDE (Interdigitated) sensor and Renewable Energy, especially Thermoelectric.

Ahmad Nizam Isa

Ahmad Nizam Isaobtained his Master of Engineering in the field of Electronic from Universiti Teknikal Malaysia Melaka (UTeM). His research interest includes Renewable Energy (Solar and Thermoelectric).

Azdiana Md Yusop

Azdiana Md Yusop obtained her PhD in Electricals, Electronics and System Engineering, Universiti Kebangsaan Malaysia. Currently doing research in Energy Harvesting System, Control System and Thermoelectric and Solar.

Mohd Faizul Mohd Sabri

Mohd Faizul Mohd Sabri  obtained his PhD in the field of MEMS at Tohoku University 2009. He is a member of the Board of Engineers, Malaysia as a Professional Engineer (PEng), a member of The Institution of Mechanical Engineers, UK and a Chartered Engineer (CEng) with the Institution of Engineers, UK. Currently, he is holding a post as the President for Malaysia Thermoelectric Society (MTES). His research interests are in thermoelectric materials and generators, lead-free solder alloys, and Micro-Electro-Mechanical Systems (MEMS).