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Item 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. © 2021Item 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. © 2022Item Multi-criteria decision-making techniques based optimum selection of phase change material and its implementation in a solar crop dryer for agricultural products(Elsevier Ltd, 2025) Kabeer, V.P.A.; Maniyeri, R.; Anish, S.The energy storage in solar thermal systems is crucial as the fluctuations in solar energy and its unavailability in the night periods adversely affects the system effectiveness. The proper selection of phase change material (PCM) for energy storage in a particular application is vital important as it directly affects the overall performance of the system. The selection of an optimum PCM for a specific application is a complex problem, requiring consideration of multiple criteria involving thermal, economic, environmental and physical aspects. The present study aims to select the optimum PCM for energy storage in a solar crop dryer, while being sustainable and cost-effective. The organic PCM alternatives with their melting temperature in the range suitable for crop drying application are selected for the study. Six widely recognized multi-criteria decision-making (MCDM) methods viz. EDAS, MOOSRA, TOPSIS, PROMETHEE, MOORA and CODAS have been employed to identify the most suitable PCM from the available alternatives. The criteria weights for optimization are determined using AHP, CRITIC and ENTROPY techniques, and their combinations. All MCDM techniques gives paraffin wax as the optimum PCM to be used as energy storage material in solar dryer. The average scores such as TOPSIS: 0.75, EDAS: 0.82, MOOSRA: 0.94, MOORA: 0.36, CODAS: 0.13 and PROMETHEE: 0.094 are obtained for paraffin wax, and are found to be highest compared with other alternatives. The sensitivity analysis carried out with weight variation method ensures the robustness and reliability of applied methods. Further, a simplified iterative computational procedure is developed to compute the required quantity of PCM and its container dimension to maintain the drying temperature for a specific duration during off-sun shine hours. The computational procedure also selects paraffin wax as the best PCM, as its required quantity is less and thus container size is small. The experimental investigation on the solar dryer, incorporating paraffin wax as the thermal storage material exhibits good agreement with the computational procedure, thereby substantiating the effectiveness of the PCM selection methodology. The paraffin wax in its optimum quantity could deliver the heat at a constant temperature of nearly 60 °C for six hours, during sun down hours and night (from 3.00 pm to 9.00 pm), which supports the PCM selection using MCDM techniques and agrees with findings of computational procedure. The absorber temperature is also able to be maintained above 50 °C for an extended period of six hours. The average air temperature of 45 °C is maintained in the dryer during the sun-down period (3.00 pm to 9.00 pm), using paraffin wax as energy storage material. With the highest benefit-cost ratio of 8.17, paraffin wax also emerged as the most cost-effective option among the PCM alternatives. © 2025 Elsevier LtdItem Design of thermal energy storage system for solar cooker: a review(Springer, 2025) Anilkumar, B.C.; Maniyeri, R.Solar cooking has been a research focus worldwide over the last few decades due to its numerous advantages, such as no running costs, non-polluting nature and ample availability. Solar cookers incorporate thermal energy storage (TES) units to enable cooking during off-sunshine hours. Within solar thermal applications, latent heat storage materials (LHSMs), particularly phase change materials (PCMs) are increasingly vital due to their superior energy storage density and isothermal working properties. The present review aims to provide a comprehensive overview of various TES unit designs integrated with cooking vessels for solar cookers. We discuss different types of solar cookers, various TES unit configurations, and the thermo-physical properties of heat storage materials. A key aspect of this work involves comparing the sizes of various TES units, derived from our previously developed computational scheme, with existing research. Prior studies often lacked specifics on the duration of off-sunshine cooking. However, determining the optimal PCM mass is crucial for designing efficient LHS units that maximize heat storage and release for sustained cooking. To address this gap, we employed a computational procedure to determine the duration for which various LHS units, integrated with box-type solar cookers, can maintain a constant cooking temperature. We also identified and compared the dimensions of containers needed to hold the optimum PCM mass. Our computational findings for the outer vessel diameter of LHS units align closely with previous studies. This computational approach offers a robust methodology for developing TES units that optimize PCM latent heat utilization, significantly enhancing solar cooker performance during sundown hours. Ultimately, we propose a pathway for improving future TES unit designs and present a strategy for marketing solar cookers. This review will be an invaluable resource for researchers, stimulating further advancements in solar cookers integrated with TES systems. © Indian Academy of Sciences 2025.