Thermal conductivity measurement of a PCM based storage system containing carbon fibers

The influence of carbon fibers on thermal conductivity enhancement of an inorganic PCM44 has been evaluated. Fibers of different length were randomly distributed and thermal conductivity measurements of the obtained composite were carried out by hot-wire method. It has been seen that the homogeneity grade of the composite (PCM + fiber) plays a fundamental role in the enhancement of heat diffusion. A linear relationship between carbon fiber loading and thermal conductivity increasing was found in a wide range of carbon loading (up to 10 wt%). The best results were obtained using micro-fibers (l = 0.2 mm): thermal conductivity quadruplicate at a fiber loading of about 7 wt%. Furthermore, the experimental results have been fitted by a literature heat transfer model.