Advanced Thermoelectric Power System Investigations for Light-Duty and Heavy-Duty Applications: Part II

Part II of this two-part paper leverages off the findings in Part I describing the mathematical basis and system modeling approach used in thermoelectric power generation (TEPG) investigations for waste heat recovery in light-duty passenger (LDP) and heavy-duty (HD) vehicles. The TEPG sytsem model has been used to; (1) investigate the behavior and interdependence of important thermal and TEPG design parameters, and (2) compare potential TEPG system power output for a variety of thermal conditions in LDP and HD vehicles. Integrated system modeling and analyses have been performed for: 1) LDP conditions of Tcxh = 700 °C (973 K) and mh= 0.01, 0.02, and 0.03 kg/sec, and 2) HD conditions of Texh = 512 °C (785 K) and mA= 0.2, 0.3, and 0.4 kg/sec. Analysis results, TEPG design parameter behavior, thermoelectric (TE) material effects, and interdependence of critical thermal / TE system design parameters are discussed. Interaction of heat exchanger performance and TEPG device performance creates critical system impacts and performance dependencies, which maximize TEPG system power outputs and create preferred heat exchanger and TEPG performance regimes. Part II demonstrates the integrated system analysis approach to heat exchanger / TEPG system performance, allowing NREL to simultaneously quantify these critical system design effects in LDP and HD vehicles. HD vehicle analysis results also indicate that 5-6 kW of electrical energy production is possible using HD vehicle exhaust waste heat.