Electricity generation from an exhaust heat recovery system utilising thermoelectric cells and heat pipes

Abstract The internal combustion engine used in majority of cars at the present time do not use their fuel input very efficiently. A majority of this energy is dissipated as heat in the exhaust. The related problems of global warming and dwindling fossil fuel supplies has led to improving the efficiency of the internal combustion engine being a priority. One method to improve the efficiency is to develop methods to utilise heat in car exhausts that is usually wasted. Two promising technologies that were found to be useful for this purpose were thermoelectric cells (TECs) and heat pipes. Therefore this project involved making a bench type, proof of concept model of power production by thermoelectric cells using heat pipes and hot engine exhaust gases. 8 cells were used and managed to produce 6.03 W when charging the battery. The system operated with a heat to electricity conversion efficiency of 1.43%. The discrepancy between the actual efficiency and the predicted efficiency of 2.31% is most likely due to the cells not operating at their optimum voltage. The predicted efficiency is approximately 1/9 of the Carnot efficiency and the actual efficiency is approximately 1/15 of the Carnot efficiency.

[1]  F. P. Brito,et al.  Heat-Pipe Assisted Thermoelectric Generators for Exhaust Gas Applications , 2010 .

[2]  David Michael Rowe,et al.  Thermoelectrics, an environmentally-friendly source of electrical power , 1999 .

[3]  Guiping Lin,et al.  Waste heat recovery using heat pipe heat exchanger for heating automobile using exhaust gas , 2003 .

[4]  Jorge Martins,et al.  Influence of Heat Pipe Operating Temperature on Exhaust Heat Thermoelectric Generation , 2013 .

[5]  D. Brigham,et al.  Thermoelectric Exhaust Heat Recovery for Hybrid Vehicles , 2009 .

[6]  Shiho Kim,et al.  A Thermoelectric Generator Using Engine Coolant for Light-Duty Internal Combustion Engine-Powered Vehicles , 2011 .

[7]  M. A. Karri,et al.  Exhaust energy conversion by thermoelectric generator: Two case studies , 2011 .

[8]  Abhijit Date,et al.  Progress of thermoelectric power generation systems: Prospect for small to medium scale power generation , 2014 .

[9]  Masayoshi Mori,et al.  Simulation of Fuel Economy Effectiveness of Exhaust Heat Recovery System Using Thermoelectric Generator in a Series Hybrid , 2011 .

[10]  F. P. Brito,et al.  Thermoelectric Exhaust Energy Recovery with Temperature Control through Heat Pipes , 2011 .

[11]  H. Goldsmid,et al.  Bismuth Telluride and Its Alloys as Materials for Thermoelectric Generation , 2014, Materials.

[12]  M. Lazard,et al.  Modeling a Thermoelectric Generator Applied to Diesel Automotive Heat Recovery , 2010 .

[13]  Nyambayar Baatar,et al.  A Thermoelectric Generator Replacing Radiator for Internal Combustion Engine Vehicles , 2011 .

[14]  Shiho Kim,et al.  Thermoelectric Power Generation System for Future Hybrid Vehicles Using Hot Exhaust Gas , 2011 .

[15]  R. Stobart,et al.  The Potential for Thermo-Electric Regeneration of Energy in Vehicles , 2009 .

[16]  D. Crane,et al.  Automotive Waste Heat Conversion to Electric Power using Skutterudite, TAGS, PbTe and BiTe , 2006, 2006 25th International Conference on Thermoelectrics.