The Experts below are selected from a list of 32400 Experts worldwide ranked by ideXlab platform
D. Buddhi - One of the best experts on this subject based on the ideXlab platform.
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thermal cycling test of few selected inorganic and organic phase change materials
Renewable Energy, 2008Co-Authors: Anant Shukla, D. Buddhi, R L SawhneyAbstract:Thermal cycling tests were performed to check the stability in thermal energy storage systems on some selected organic and inorganic phase change materials (PCMs). The possibility of using these PCMs in thermal energy storage systems were examined on the basis of thermal, chemical and kinetic criteria. Organic and inorganic PCMs were selected to check their thermal stability. Inorganic PCMs were not found suitable after some cycles while thermal cycling for organic PCMs were undertaken up to 1000 thermal cycles and has shown a gradual change in melting temperature and latent Heat of Fusion. The PCMs were then checked with differential scanning calorimeter (DSC) for their latent Heat storage capacity and melting temperature change.
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thermal cycle testing of calcium chloride hexahydrate as a possible pcm for latent Heat storage
Solar Energy Materials and Solar Cells, 2008Co-Authors: V V Tyagi, D. BuddhiAbstract:In order to study the changes in latent Heat of Fusion and melting temperature of calcium chloride hexahydrate (CaCl2·6H2O) inorganic salt as a latent Heat storage material, a thousand accelerated thermal cycle tests have been conducted. The effect of thermal cycling and the reliability in terms of the changing of the melting temperature using a differential scanning calorimeter (DSC) is determined. It has been noticed that the CaCl2·6H2O melts between a stable range of temperature and has shown small variations in the latent Heat of Fusion during the thermal cycling process. Thus, it can be a promising phase change material (PCM) for Heating and cooling applications for various building/storage systems.
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thermal performance evaluation of a latent Heat storage unit for late evening cooking in a solar cooker having three reflectors
Energy Conversion and Management, 2003Co-Authors: D. Buddhi, Smita Sharma, Atul SharmaAbstract:In this paper, a phase change material (PCM) storage unit for a solar cooker was designed and developed to store energy during sunshine hours. The stored energy was utilised to cook food in the late evening. Commercial grade acetanilide (melting point 118.9 °C, latent Heat of Fusion 222 kJ/kg) was used as a latent Heat storage material. Evening cooking experiments were conducted with different loads and loading times during the winter season. The experimental results showed that late evening cooking is possible in a solar cooker having three reflectors to enhance the incident solar radiation with the PCM storage unit.
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accelerated thermal cycle test of acetamide stearic acid and paraffin wax for solar thermal latent Heat storage applications
Energy Conversion and Management, 2002Co-Authors: Atul Sharma, S D Sharma, D. BuddhiAbstract:1500 accelerated thermal cycle tests have been conducted to study the changes in latent Heat of Fusion and melting temperature of commercial grade acetamide, stearic acid and paraffin wax. It has been noticed that the stearic acid melts over a wide range of temperature, has shown two melting points and has large variations in latent Heat of Fusion. Paraffin wax and acetamide have shown reasonably good thermal stability for melting temperature and variations in latent Heat of Fusion during the cycling process.
Ahmet Sari - One of the best experts on this subject based on the ideXlab platform.
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thermal reliability test of some fatty acids as pcms used for solar thermal latent Heat storage applications
Energy Conversion and Management, 2003Co-Authors: Ahmet SariAbstract:Abstract The purpose of this study is to determine the thermal reliability of stearic acid, palmitic acid, myristic acid and lauric acid as latent Heat energy storage materials with respect to various numbers of thermal cycles. The fatty acids, as phase change materials (PCMs), of industrial grade (purity between 90% and 97%) were subjected to accelerated thermal cycle tests. The differential scanning calorimetry (DSC) analysis technique was applied to the PCMs after 0, 120, 560, 850 and 1200 melt/freeze cycles in order to measure the melting temperatures and the latent Heats of Fusion of the PCMs. The DSC results indicated that the change in melting temperature for the PCMs was in the range of 0.07–7.87 °C, and the change in latent Heat of Fusion was −1.0% to −27.7%, except for stearic acid between 560 and 1200 melt/freeze cycles. However, the decrease in the latent Heats of Fusion for all the PCMs was not regular with increasing thermal cycles. The experimental results also show that the investigated fatty acids as latent Heat energy storage materials have a good thermal reliability in view of the latent Heat of Fusion and melting temperature with respect to thermal cycling for thermal energy storage applications in the long term.
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thermal characteristics of a eutectic mixture of myristic and palmitic acids as phase change material for Heating applications
Applied Thermal Engineering, 2003Co-Authors: Ahmet SariAbstract:Abstract The melting temperatures of the palmitic acid (PA) (61.2 °C) and the myristic acid (MA) (52.2 °C) are high for solar thermal energy storage under the climate conditions of the some regions in Turkey. However, their melting temperatures can be adjusted to a suitable value by addition of MA to PA. In this study, the thermal analysis by differential scanning calorimetry technique shows that the mixture of MA and PA with 58.0 wt% MA forms a eutectic mixture with melting temperature of 42.6 °C and the latent Heat of Fusion of 169.7 J g −1 . The melting temperature and latent Heat of Fusion of MA–PA eutectic mixture make it a suitable material for energy storage in passive solar space and greenhouse Heating systems under the climate conditions of some residential and agricultural regions in Turkey. The present study also deals with the experimental establishment of thermal characteristics of the eutectic mixture as a phase change material in a vertical concentric two pipes––energy storage system. Reynolds and Stefan numbers were selected as experimental parameters and used for the evaluation of the results. The experimental results prove that the MA–PA eutectic mixture has attractive thermal characteristics during the melting and the solidification processes and it is a potential latent Heat storage material for Heating applications with respect to the climate requirements in Turkey.
Atul Sharma - One of the best experts on this subject based on the ideXlab platform.
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development of an acetanilide benzoic acid eutectic phase change material based thermal energy storage unit for a passive water Heating system
Bulletin of Materials Science, 2019Co-Authors: Khushboo Purohit, V V S Murty, R C Dixit, Atul SharmaAbstract:In the present work, two organic phase change materials (PCMs) are used to develop a new eutectic PCM for sharp melting point with high latent Heat of Fusion. Optimized eutectic can be suitable for a passive water Heating system (PWHS). The binary eutectic PCMs consisting of different compositions of acetanilide and benzoic acid are prepared and optimized at a composition of 30:70 by weight percentage. Optimized samples are characterized by using differential scanning calorimetry (DSC), Fourier transform infrared spectrophotometry and field-emission scanning electron microscopy. The results of DSC showed that melting temperature and latent Heat of the optimized eutectic PCM is found to be $$75.56{^{\circ }}\hbox {C}$$ and $$193.56\,\hbox {J}\,\hbox {g}^{-1}$$ . A negligible change in melting temperature and latent Heat of Fusion of the optimized eutectic based PCM after 100 accelerated Heating and cooling cycles is observed. The prepared eutectic PCM is employed as a thermal energy storage (TES) system for PWHS. The experimental results of a eutectic PCM based TES system for the PWHS show that the use of eutectic helps in enhancing the maximum utility of solar energy during off-shine hours.
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thermal performance evaluation of a latent Heat storage unit for late evening cooking in a solar cooker having three reflectors
Energy Conversion and Management, 2003Co-Authors: D. Buddhi, Smita Sharma, Atul SharmaAbstract:In this paper, a phase change material (PCM) storage unit for a solar cooker was designed and developed to store energy during sunshine hours. The stored energy was utilised to cook food in the late evening. Commercial grade acetanilide (melting point 118.9 °C, latent Heat of Fusion 222 kJ/kg) was used as a latent Heat storage material. Evening cooking experiments were conducted with different loads and loading times during the winter season. The experimental results showed that late evening cooking is possible in a solar cooker having three reflectors to enhance the incident solar radiation with the PCM storage unit.
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accelerated thermal cycle test of acetamide stearic acid and paraffin wax for solar thermal latent Heat storage applications
Energy Conversion and Management, 2002Co-Authors: Atul Sharma, S D Sharma, D. BuddhiAbstract:1500 accelerated thermal cycle tests have been conducted to study the changes in latent Heat of Fusion and melting temperature of commercial grade acetamide, stearic acid and paraffin wax. It has been noticed that the stearic acid melts over a wide range of temperature, has shown two melting points and has large variations in latent Heat of Fusion. Paraffin wax and acetamide have shown reasonably good thermal stability for melting temperature and variations in latent Heat of Fusion during the cycling process.
V V Tyagi - One of the best experts on this subject based on the ideXlab platform.
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long term thermal and chemical reliability study of different organic phase change materials for thermal energy storage applications
Journal of Thermal Analysis and Calorimetry, 2016Co-Authors: R K Sharma, P Ganesan, V V TyagiAbstract:The purpose of this experimental study is to determine the thermal and chemical reliability of organic phase change materials (O-PCMs) viz. paraffin, palmitic acid, and myristic acid for 1500 accelerated melt/freeze. The differential scanning calorimeter (DSC) was used to measure the melting temperature and the latent Heat of Fusion at zeroth cycle and after 100th, 500th, 1000th, and 1500th thermal cycles. The DSC results show the gradual changes in the value of thermophysical properties of all the tested PCMs. The changes in melting temperature of paraffin, palmitic acid, and myristic acid have been found in the range of +0.72 to +3.27, −0.29 to +1.76, and −2.09 to +1.5 °C, respectively, and the latent Heat of Fusion in −9.8 to 14.2, 3.3 to 17.8, and 0.9 to 9.7 %, respectively. The Fourier transform and infrared spectroscopy (FT-IR) technique was used to investigate the changes in the compositional/functional group of the O-PCMs before and after thermal cycles. The FT-IR spectrum confirms the chemical stability during the thermal cycle test. The experimental results show that these organic PCMs possess a good thermal reliability in terms of melting temperature and the latent Heat of Fusion and chemical stability during thermal cycle testing.
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thermal cycle testing of calcium chloride hexahydrate as a possible pcm for latent Heat storage
Solar Energy Materials and Solar Cells, 2008Co-Authors: V V Tyagi, D. BuddhiAbstract:In order to study the changes in latent Heat of Fusion and melting temperature of calcium chloride hexahydrate (CaCl2·6H2O) inorganic salt as a latent Heat storage material, a thousand accelerated thermal cycle tests have been conducted. The effect of thermal cycling and the reliability in terms of the changing of the melting temperature using a differential scanning calorimeter (DSC) is determined. It has been noticed that the CaCl2·6H2O melts between a stable range of temperature and has shown small variations in the latent Heat of Fusion during the thermal cycling process. Thus, it can be a promising phase change material (PCM) for Heating and cooling applications for various building/storage systems.
Smita Sharma - One of the best experts on this subject based on the ideXlab platform.
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thermal performance evaluation of a latent Heat storage unit for late evening cooking in a solar cooker having three reflectors
Energy Conversion and Management, 2003Co-Authors: D. Buddhi, Smita Sharma, Atul SharmaAbstract:In this paper, a phase change material (PCM) storage unit for a solar cooker was designed and developed to store energy during sunshine hours. The stored energy was utilised to cook food in the late evening. Commercial grade acetanilide (melting point 118.9 °C, latent Heat of Fusion 222 kJ/kg) was used as a latent Heat storage material. Evening cooking experiments were conducted with different loads and loading times during the winter season. The experimental results showed that late evening cooking is possible in a solar cooker having three reflectors to enhance the incident solar radiation with the PCM storage unit.
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accelerated thermal cycle test of latent Heat storage materials
Solar Energy, 1999Co-Authors: Smita SharmaAbstract:Accelerated laboratory experiments have been conducted to study the change in latent Heat of Fusion, melting temperature and specific Heat of commercial-grade stearic acid, acetamide and paraffin wax subjected to repeated 300 melt/freeze cycles. The latent Heat of Fusion, melting temperature and specific Heat of the samples were measured after 0, 20, 50, 70, 100, 150, 200, 250 and 300 thermal cycles using a differential scanning calorimeter. Acetamide and paraffin wax were found to be more stable phase change materials (PCMs). However, acetamide absorbs moisture from the surrounding atmosphere.
