Improving the Efficiency of Waste Heat Recovery Systems by Means of a Novel Combined Turbine-Peltier System

Abstract

A novel Combined Turbine-Peltier System (CTPS) was designed and built to harness both thermal and kinetic energies of the exhaust gas of an engine and convert it to electrical power. The Turbine-Generator was connected to the turbocharger shaft and the Thermoelectric Generators (TEG) were assembled between the heat exchangers mounted on the exhaust pipe. The Computational Fluid Dynamics (CFD) approach and Taguchi optimization technique were employed in order to analyze and optimize the flow field and heat transfer characteristics of the system. Based on the optimized numerical results, an experimental setup was designed and manufactured, and the experiments were conducted on an engine operating at different load and speed conditions. The harvested maximum power output for a single TEG was 5.5 W with the thermal efficiency of 3.6% and the net output power of the CTPS was 190 W obtained at the engine speed of 3000 rpm. The maximum increase in the power of the ICE combined with CTPS method was calculated as 1.6%. The obtained numerical results were compared with the experiments and showed a good accordance with the maximum deviation of 6%.