Development of sunlight-driven eutectic phase change material nanocomposite for applications in solar water heating

Organic phase change materials (PCMs) have been utilized as latent heat energy storage medium for
effective thermal management. In this work, a PCM nanocomposite, consisting of a mixture of two organic
PCMs (referred to as eutectic gel PCM) and minimal amount (0.5 wt%) of nanographite (NG) as a
supporting material, was prepared. Differential scanning calorimeter was used to determine the melting
temperature and latent heat of pristine PCM, paraffin (61.5 °C and 161.5 J/g), eutectic gel PCM (54 °C and
158 J/g) and eutectic gel PCM nanocomposite (53.5 °C and 155 J/g). The prepared PCM nanocomposites
exhibited enhanced thermal conductivity and ultrafast thermal charging characteristics. The nanocomposites
were employed for two different applications: (i) providing hot water using an indigenously fabricated
solar water heating (SWH) system and (ii) solar rechargeable glove that can be rapidly warmed
and used. Experimental results on SWH system show that the use of PCM nanocomposites helps to increase
the charging rate of PCM while reducing the discharging rate of heat by PCM to water, thus enhancing
the maximum utilization of solar energy and hence improving the efficiency of the SWH system.
The experimental results on solar rechargeable glove revealed that the glove has the ability to retain the
temperature up to 3 hours.