Review of PCMS and heat transfer enhancement methods applied in parabolic trough solar plants thermal storage systems
Solar thermal power generation requires a cost effective thermal storage system. The existing two tank system is very expensive due to the storage material inventory. The use of phase change materials (PCMs) offers higher storage density. A review of potential PCMs was conducted in order to come up with commercially available ones having suitable properties. Most available PCMs have low thermal conductivity making heat transfer enhancement necessary for power applications. The various methods of heat transfer enhancement in latent heat storage systems were also reviewed systematically. The review showed that three commercially - available PCMs are suitable in the operating temperature range of parabolic trough plants. Many heat transfer enhancement methods have been investigated in the literature but the use of aluminium fins is the most promising in the temperature range of 250 - 330oC. Many eutectic mixtures of materials have potential for use but discrepancies exist in their reported melting temperature and latent heat of fusion.
Keywords: Latent heat, high temperature, t hermal conductivity enhancemen