Thermal storage performances of the quaternary ammonium tetrachlorocuprate [1-C H2+1N(CH3)3]2CuCl4 (n = 16, 18) multiphase state as high efficient phase change materials (PCMs)

The present study explores suitability of two phase change materials (PCM) for development of an active thermal storage system for a solar drying kiln by studying their melting and solidification behaviors. A double glass glazing prototype solar kiln was used in the study. The storage system consisted of a water storage tank with PCM placed inside the water in high density polyethylene containers. The water in the tank was heated with help of solar energy using an evacuated tube collector array. The melting and solidification temperature curves of PCM were obtained by charging and discharging the water tank. The study illustrated the utility of the PCM in using the stored thermal energy during their discharge to enhance the temperature inside the kiln. The rate of temperature reduction was found to be higher for paraffin wax as compared to a fatty acid based PCM. The water temperature during the discharge of the PCM showed dependence on the discharge characteristics of each PCM suggesting their suitability in designing active thermal storage systems.

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Performance Improvement of a Household Refrigerator using Phase Change Material

Journal of Manufacturing Engineering ◽

10.37255/jme.v16i1pp032-041 ◽

2021 ◽

Vol 16 (1) ◽

pp. 032-041

Author(s):

Pradeep N ◽

Somesh Subramanian S

Keyword(s):

Energy Storage ◽

Phase Change ◽

Phase Change Material ◽

Phase Change Materials ◽

Energy Savings ◽

Storage System ◽

Thermal Storage ◽

Latent Heat Storage ◽

Peak Loads ◽

Change Material

Thermal energy storage through phase change material has been used for wide applications in the field of air conditioning and refrigeration. The specific use of this thermal storage has been for energy storage during low demand and release of this energy during peak loads with potential to provide energy savings due to this. The principle of latent heat storage using phase change materials (PCMs) can be incorporated into a thermal storage system suitable for using deep freezers. The evaporator is covered with another box which has storage capacity or passage through phase change material. The results revealed that the performance is increased from 3.2 to 3.5 by using PCM.

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Thermal Storage of Nitrate Salts as Phase Change Materials (PCMs)

Materials ◽

10.3390/ma14237223 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7223

Author(s):

Marco A. Orozco ◽

Karen Acurio ◽

Francis Vásquez-Aza ◽

Javier Martínez-Gómez ◽

Andres Chico-Proano

Keyword(s):

Energy Storage ◽

Phase Change ◽

Sodium Nitrite ◽

Phase Change Materials ◽

Storage Capacity ◽

Thermal Storage ◽

Potassium Nitrate ◽

Ternary Mixtures ◽

Scanning Calorimetry ◽

Nitrate Salts

This study presents the energy storage potential of nitrate salts for specific applications in energy systems that use renewable resources. For this, the thermal, chemical, and morphological characterization of 11 samples of nitrate salts as phase change materials (PCM) was conducted. Specifically, sodium nitrate (NaNO3), sodium nitrite (NaNO2), and potassium nitrate (KNO3) were considered as base materials; and various binary and ternary mixtures were evaluated. For the evaluation of the materials, differential Fourier transform infrared spectroscopy (FTIR), scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) to identify the temperature and enthalpy of phase change, thermal stability, microstructure, and the identification of functional groups were applied. Among the relevant results, sodium nitrite presented the highest phase change enthalpy of 220.7 J/g, and the mixture of 50% NaNO3 and 50% NaNO2 presented an enthalpy of 185.6 J/g with a phase change start and end temperature of 228.4 and 238.6 °C, respectively. This result indicates that sodium nitrite mixtures allow the thermal storage capacity of PCMs to increase. In conclusion, these materials are suitable for medium and high-temperature thermal energy storage systems due to their thermal and chemical stability, and high thermal storage capacity.

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The effect of metal wool on the charging and discharging rate of the phase transition thermal storage material

Eastern-European Journal of Enterprise Technologies ◽

10.15587/1729-4061.2021.239065 ◽

2021 ◽

Vol 4 (5(112)) ◽

pp. 12-20

Author(s):

Olga Khliyeva ◽

Vitaly Zhelezny ◽

Aleksey Paskal ◽

Yana Hlek ◽

Dmytro Ivchenko

Keyword(s):

Power Systems ◽

Phase Change ◽

Phase Change Materials ◽

Thermal Storage ◽

Heating Time ◽

Phase Changes ◽

Storage Material ◽

Heat Accumulation ◽

Heating And Cooling ◽

Efficiency And Reliability

Thermal energy storage (TES) plays an important role in solar heat power systems. The use of phase change materials (PCM) and selecting additives to increase the rate of heat accumulation is a promising way to increase the efficiency and reliability of such systems. The objects of the study were pure paraffin wax (PW) and composite PCMs based on it (containing aluminum and copper wool of 30 and 45 μm in diameter, respectively). An experimental setup with a cylindrical measuring cell was created, which was also considered as a model of a capsule with a thermal storage material. The rate of temperature change in the pure PW sample and samples of composite PCMs was experimentally measured. Two modes of heating and cooling were investigated: from 48 to 59 °C (mode with a phase change) and from 30 to 40 °C (mode without phase changes). Heating time from 48 to 59 °C for the PW sample was 13 min., for the PW samples with the content of aluminum wool of 0.00588 and 0.01780 m3·m-3 − 11 and 10.5 min., for the PW samples with the content of copper wool of 0.00524 and 0.01380 m3·m-3 − 11 and 8 min., correspondingly. The minimum heating time from 30 to 40 °C was 6 min. for the sample of PW with 0.01380 m3·m-3 of copper wool in comparison with 9 min. for the sample of pure PW. The expediency of using copper wool as an additive to thermal storage materials of PW to increase the charging and discharging rate of TES devices without significantly raising their price was confirmed. The presence of metal wool in molten PW suppresses bottom-up convective currents, so the main mechanism of heat transfer is thermal conductivity. This fact will contribute to a faster equalization of the temperature field by the height of heat storage capsules

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