Cooling system investigation of thermoelectric generator used for marine waste heat recovery

Abstract

There has been great interest on exploring the potential of waste heat extraction using thermoelectric generator (TEG) system on marine application, due to great amount of exhaust gas volume, many potential locations with consistent high temperature and availability of infinite cooling sea water. To improve the overall output performance of TEG system in terms of efficiency, proper system level engineering and integration have been considered crucial besides development of thermoelectric materials with larger ZT (figure of merit) value and optimal control strategy of electrical interface system. In this work, preliminary experimental investigation and numerical modelling optimization on the cooling system for a thermoelectric module level device are conducted. The predicted open-circuit voltages by thermoelectric simulation for device with conventional tubed water cooling plate are in good agreement with the measured experimental data for various hot exhaust temperatures. The model is then revised for further simulation to optimize the cooling plate design by examining detailed thermal performance and electrical current-voltage characteristics for the thermoelectric module device with varying electrical load. These investigations demonstrate that a local effective cooling system is important for high efficiency TEG implementation. This modulelevel observation serves to perceive how TEG system integrates as well as indicate potential improvement for TEG power conversion system. With good accuracy, the employed simulation tool is capable of rapidly characterizing TEG system level performance in future work.