Advanced Energy Technologies
Mohammad Saleh Barghi Jahromi; Vali Kalantar; Mohammad Sefid; Masoud Iranmanesh; Hadi Samimi Akhijahani
Abstract
Paraffin waxes are widely used as commercial organic heat storage phase changes (PCM) for many applications due to their suitable properties. Significant heat from fusion, nonpoisonous and stable properties, no phase separation, and the phase process result in a small volume change. Meanwhile, they are ...
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Paraffin waxes are widely used as commercial organic heat storage phase changes (PCM) for many applications due to their suitable properties. Significant heat from fusion, nonpoisonous and stable properties, no phase separation, and the phase process result in a small volume change. Meanwhile, they are subject to low thermal conductivity. The thermal conductivity of PCMs can be increased by different techniques such as the use of dispersion of particles or nanomaterials with high conductivity in PCM and the use of metal foams. The use of nanoparticles has such disadvantages as high cost and particle deposition after various cycles. Hence, in this study, some experiments were carried out to investigate the effect of porous media like copper foam and iron wool as the filler instead of nanomaterials on improving the heat conductivity of PCM. The results show that the porous foam increases the heat transfer and during the charging operation, the temperature of the porous plate wall increases continuously at the same rate as the paraffin. At 2400 s, the temperature of pure PCM, iron wool, and copper foam reaches 67.3, 72.5, and 73.27℃, respectively. The optimal mode is the one in which the copper absorber plate is connected to the copper foam, thus reducing the charging time by 600 s compared to pure PCM and saving 75% of energy. Connecting the copper absorber plate to the iron wool has a good thermal performance and stores 70.83% of energy. Thus, iron wool has an acceptable performance and is suitable for storage systems.
Advanced Energy Technologies
Mohammed Ali Sami Mahmood; Rodionov Yuriy Viktorovich; Alexandr Viktorovich Shchegolkov
Abstract
Researchers worldwide are studying thermal energy storage with phase change materials because of their substantial benefits in the enhancement of energy efficiency of thermal drying systems. A two-stage convective-vacuum impulsive drying plant is a technology for the manufacturing of chemical and food ...
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Researchers worldwide are studying thermal energy storage with phase change materials because of their substantial benefits in the enhancement of energy efficiency of thermal drying systems. A two-stage convective-vacuum impulsive drying plant is a technology for the manufacturing of chemical and food products with high quality and low energy costs. Energy consumption during the drying process is the main indicator in terms of economy. In this paper, a brief and focused review of the peculiarities of TEAs with PPCMs and opportunities of their application in such drying systems is done and discussed. The paper described the mentioned manufacturing system. The advantages of paraffin wax and thermal conductivity improvement techniques were demonstrated for their use as heat storage materials in CVID drying units. The results of similar previous studies were presented. The results of the experimental studies conducted by the researchers proved that the use of heat accumulators with PCMs increased the overall energy efficiency of drying systems. Finally, integration of TEAs based on modified PPCMs in the CVID system was recommended to intensify thermal energy, reduce thermal influence on the main indicators of the vacuum pump during the evacuation process, and decrease production costs.
Advanced Energy Technologies
Subramanian Kumaravel; Nagaraj MeenakshiSunadaram; Govindarajan Bharathiraja
Abstract
In this research, a piece of copper scrap was placed in the 1m × 1m base of a single-slope solar still. An automated system steadily dripped salt water into the basin of the solar still. The experiment utilized dripping salt water and energy storage materials such as copper and brass scrap. Research ...
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In this research, a piece of copper scrap was placed in the 1m × 1m base of a single-slope solar still. An automated system steadily dripped salt water into the basin of the solar still. The experiment utilized dripping salt water and energy storage materials such as copper and brass scrap. Research has shown that the presence of copper scrap in the basin, combined with a shallow layer of salt water, has a significant impact on the distillate output. However, the high thermal capacity of the salt water in the basin can lead to reduced production. As more salt water is added to the basin, the temperature difference between the water inside and the glass cover increases. Based on the experimental results, the calculated yield is satisfactory, and the overall thermal efficiency remains at 71.3%. The production rate is also influenced by the diffusion process on the south-facing condensing cover. The temperatures of water, glass, and air, as well as their combined effects, are measured and analyzed.
