Faculty Publications

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    Optimum selection of phase change material for solar box cooker integrated with thermal energy storage unit using multi-criteria decision-making technique
    (Elsevier Ltd, 2021) Anilkumar, B.C.; Maniyeri, R.; Anish, S.
    Various thermal energy storage (TES) materials are used to increase the efficacy of solar cooker in off-sun hours. For the past few decades, phase change materials (PCMs) used as heat storage medium have become research interest. Selection of optimum PCM is important for the effective and efficient heat storage. Therefore, the main objective of the current study is to select the optimum PCM among the alternatives to be used for TES unit incorporated in solar box cooker (SBC). The PCMs are pre-screened among the alternatives used in earlier works based on the melting temperature. The optimum PCM is then selected with the aid of different multi-criteria decision -making (MCDM) techniques like TOPSIS, EDAS and MOORA. The criteria weights required for the optimization algorithm is found by using AHP, ENTROPY and CRITIC methods. Also, compromised values between the weights obtained through these methods are computed. The optimization algorithms are solved using MATLAB. The results of all MCDM techniques show that erythritol is the best alternative for the TES medium incorporated in the SBC. Further, the optimum mass of PCM and dimensions of the TES unit required for the SBC to operate during sun down hours for some specific duration is calculated by using a simple iterative solver developed with MATLAB. There is good agreement between the computational procedure and experimental study using paraffin wax as the TES medium. The iterative solution procedure also selects erythritol to be the best alternative as it required lesser quantity compared with other PCMs. Therefore, we recommend erythritol as the best PCM for the SBC incorporated with TES unit. © 2021
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    Modified thermal energy storage unit for solar cookers using iterative design algorithm
    (Elsevier Ltd, 2022) Anilkumar, B.C.; Maniyeri, R.; Anish, S.
    The use of phase change materials (PCMs) as thermal energy storage (TES) mediums has gained notable attention in recent years due to their high energy density and constant temperature characteristics which makes them suitable for solar cookers (SCs). Therefore, the primary objective of this study is to develop a modified TES unit containing PCM as heat storage medium incorporated with cooking vessel for SCs. The TES units use PCM filled on all sides, including the lid, enhancing heat transfer to food load. The design of TES unit is carried out by developing computational procedure. MATLAB code is written to implement the iterative procedure, simplifying exhaustive calculations required for optimizing and designing the TES unit. The present work also aims to design, fabricate and test different geometries of TES units using paraffin wax as the PCM. After six hours, cooking load temperature in all geometries of TES units reached the melting point of PCM. TES units with cylindrical shapes perform best among hexagon and square designs. Through computational procedure, cylindrical configuration is the best as it takes least amount of PCM to keep steady temperature over a specific period. Based on the computational procedure developed in this study, TES container will be designed to enhance SC performance during sundown hours and maximize the use of latent heat stored within the PCM. © 2022