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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 AN ITERATIVE ALGORITHM FOR DESIGNING AND SCALING OF PARABOLIC TROUGH COLLECTOR BASED SOLAR AGRO-DRYING SYSTEM(Begell House Inc., 2025) Kabeer, V.P.A.; Maniyeri, R.; Anish, S.This work proposes a simple and robust iterative algorithm for designing and scaling an indirect solar agro-drying system, which harvests thermal energy for drying using a parabolic trough collector (PTC). Separate computational procedures are developed for the design of the PTC by considering receiver tubes with and without a glass envelope. The computational procedure starts with the total heat requirement in the drying chamber and considers various heat losses and heat loss coefficients for the PTC receiver tube. The equations for various modes of heat losses in receiver tubes with and without a glass envelope are identified and formulated. Using thermal network and heat balance analysis, the expressions for various heat losses and overall heat loss coefficient are formulated in both cases. Required aperture area for the reflector surface of the PTC can be obtained in terms of overall heat loss coefficient and the collector heat removal factor. The tedious equations involved in computational procedure are solved using an iterative algorithm by developing a code in MATLAB. The results obtained from parametric analysis conducted using computational procedure reveals that heat losses and area of PTC required for providing drying thermal energy will be more if the receiver tube of PTC is without glass cover. The iterative algorithm described here can be used to optimize the design parameters and thus helps researchers in designing and sizing the components required for drying agro-based products. The algorithm will also help to scale the size of PTC and drying chamber based on the quantity and item to be dried. © 2025 by Begell House, Inc.Item 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 Ltd