Experiments on Waste Heat Thermoelectric Generation for Passenger Vehicles.

Area of Science:

• Automotive Engineering
• Thermoelectric Energy Conversion
• Waste Heat Recovery

Background:

• Passenger vehicles generate significant waste heat unsuitable for direct use.
• Thermoelectric generators (TEGs) offer a potential solution for converting waste heat into electricity.
• Optimizing TEG design for automotive applications requires balancing heat collection efficiency with minimal pressure drop.

Purpose of the Study:

• To design and test a lab-scale thermoelectric generator (TEG) for passenger vehicle waste heat recovery.
• To achieve a sufficient low-pressure drop while maximizing energy harvesting.
• To evaluate the performance of the TEG system under simulated engine conditions.

Main Methods:

• Simulated a 2.0 L petrol engine's waste heat using an electric heater and air circulation.
• Designed a TEG with an aluminum-finned heat collector, 20 thermoelectric modules, and water-cooled heat sinks.
• Conducted experiments to measure power load, pressure drop, heat collection, thermoelectric, and overall efficiencies.

Main Results:

• Achieved a maximum electric power output of 36.4 W with a pressure drop of only 36 Pa.
• Recorded a heat collection efficiency of 46.5% and a thermoelectric efficiency of 2.88%.
• Attained an overall system efficiency of 1.21%, exceeding the 1% target.

Conclusions:

• Demonstrated the first waste-heat-recovering TEG prototype with over 1% efficiency and a low pressure drop (<50 Pa).
• Highlighted challenges in fully extracting maximum electric power from the system.
• Showcased improved battery charging efficiency using a maximum power point tracking converter.