Pulsating heat pipe and thermo-electric generator jointly applied in renewable energy exploitation: Analytical and experimental investigations

In order to effectively harvest solar energy and waste thermal, pulsating heat pipes (PHPs) could be utilized to promote the hot end temperature of the thermoelectric modules (TEMs) and thus enhance its conversion effi-ciency. This paper explored a novel approach of recovering low grade energy and conversion to electricity utilizing PHP assisted with TEG. This research fully analyzed the effects of various working fluids, input powers, filling ratios, inclination angles and air velocities on the thermo-hydrodynamic and electricity conversion per-formance of PHP-TEG hybrid system. Our results demonstrated that the peak-to-peak amplitude of output voltage mainly depends on heat inputs and working fluids, and independent of the filling ratios; the inclination angle (from 30 degrees to 90 degrees) has slight effects on the heat transfer performance and thermoelectric generation of PHP-TEG system, due to the advantages of surface tension. In addition, the inlet temperature and flow velocity of cooling water on the thermal recovery efficiency and thermo-electricity conversion performance were further investigated. These results indicated the best heat recovery performance of 80.12% and the maximum ther-moelectric conversion efficiency of 1.22% were achieved simultaneously at the situation of 10 degrees C and 600 mL/ min of cooling water. Present investigation could contribute to waste thermal recovery and electronic cooling applications.