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Author: search.filters.author.Ahammed, M.E.Subject: search.filters.subject.Phase change materials

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    Thermal behavior of composite phase change material of polyethylene in a shell and coil-based thermal energy storage: Numerical analysis
    (Elsevier Ltd, 2023) Sheikh, M.I.A.R.; Ahammed, M.E.; Gumtapure, V.
    Energy management and environmental sustainability are important concerns across the world at present. In that context, using recycled waste material such as polyethylene as a phase change material (PCM) in a latent heat storage (LHS) system fulfils both motives. However, effective energy conversion requires proper design of thermal energy storage (TES) and improvement of thermophysical properties of the working material. In the present numerical analysis, a shell and coil-based TES is considered with linear low-density polyethylene (LLDP) as base material to be compounded with functionalized graphene in three different concentrations such as 1 %, 3 %, and 5 %, called composite phase change material i.e., CPCM1, CPCM2, and CPCM3 respectively. The diameter ratio between the coil and shell of TES, termed the geometrical ratio (Gr) is taken as 0.3, 0.5, and 0.7 in the analysis, whereas the coil's pitch length (pc) is varied from 10 mm to 30 mm. The orientation of TES is also varied from horizontal (0°) to vertical position (90°) with an interval of 30° inclination. Results reveal that the charging time for the complete liquefaction of storage material decreases a maximum of 65 % in the case of CPCM 3 with 5 % graphene. Increasing the heat supply from 125 W to 250 W sharply decreases the charging time, however, further increasing heat power affects moderately. The charging time gradually decreases to 56 % and 54 % in the case of LLDP and CPCM 2 respectively as Gr increases from 0.3 to 0.7 in both cases. The pitch length effect on the thermal performance of TES is found to be negligible. The analysis shows that the horizontal position of TES accrues the lowest charging time for the thorough melting of PCM. © 2023 Elsevier Ltd
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    Numerical analysis of polyethylene based nano-enhanced phase change material in cylindrical storage system
    (Taylor and Francis Ltd., 2024) Sheikh, M.I.A.R.; Gumtapure, V.; Ahammed, M.E.
    Environmental sustainability encompasses various dimensions like waste management, energy conservation, and environmental impact. The use of waste plastic; Linear Low-density polyethylene (LLDPE) as a phase change material (PCM) offers a sustainable solution for energy and the environment. This study investigates LLDPE/ functionalize graphene composites for latent heat storage using a shell and helical coil for effective energy conversion. The simulation is carried out for constant flux and constant temperature heat supply to understand the influence of nano additives and geometrical parameters such as spiral coil diameter (Dc), pitch (Pc), and orientation of storage unit (θ). The result reveals that nano additive influence effectively and reduces the charging time approximately from 20 to 40% for 1–5% of nano-addition. Simulation results reveals that the spiral coil diameter is crucial for melting and heat transmission. The overall melting time is decreased by up to 56% by increasing the spiral coil diameter from 21 to 49 mm for LLDPE while the effect of pitch length variation is found not significant. The constant temperature heating at 160, 250 and 340°C gives effective results for charging time improvement. The geometrical orientations from 0 to 90 degrees report that the horizontal position is the best orientation for energy storage. © 2024 Informa UK Limited, trading as Taylor & Francis Group.