Investigation of thermophysical properties of natural zeolite plates enhanced with graphite powder for thermal management of PV thermal systems

The use of natural zeolite plates for heat management and energy storage in PV thermal (PVT) systems is proposed for the first time. In this study, the production process of the natural zeolite plates were informed. The TGA results of the different grain sizes of natural zeolites, graphite powder and their mixtures were analyzed. The effects of the enhancement of the natural zeolites by graphite powder on the thermo-physical properties were investigated. Specific heat values the natural zeolites and graphite powder at different temperatures were reported. The variation of the thermal conductivity (W/mK) of the natural zeolites with different granule sizes and graphite with temperature were investigated and the variations of the thermal diffusivity (m(2)/s) and heat capacity (J/m(3)C) of the natural zeolites and graphite powder with temperature were analyzed. The variations of the thermal conductivity values of natural zeolite mixtures and plates enhanced with graphite powder with the ratio of 2, 5, 10, 15, and 20%. As the graphite ratio increases, the thermal conductivity value of the natural zeolite plates increases. The thermal conductivity values have been reached as 0.745 W/mK for 20% ratio of graphite powder enhancement for the natural zeolite plates.