Thermal performance of a tapered store containing tubes of phase change material: Cooling cycle

The thermal performance of a tapered store, including constant cross-section phase change material (PCM) tubes, was investigated. Three different air flow rates and four different air inlet temperatures were used in the tests. The PCM utilized was a mixture of sodium sulphate and sodium chloride salts, together with additives and gelling agent. The results showed that the cycle time was shortened as the air inlet temperature was decreased. The same effect was obtained when the air flow rate was increased. An even temperature distribution was observed at the center position within the PCM along the tubes. This was a consequence of increasing the air velocity along the store. Heat transfer rates along the store were found to be close to each other. The average effectiveness of the store was found to be around 44%. Copyright (C) 1996 Elsevier Science Ltd