Geometry-induced thermal storage enhancement of shape-stabilized phase change materials based on oriented carbon nanotubes

2019 ◽  
Vol 254 ◽  
pp. 113688 ◽  
Author(s):  
Xiao Zhu ◽  
Liang Han ◽  
Yunfeng Lu ◽  
Fei Wei ◽  
Xilai Jia
Keyword(s):  
Carbon Nanotubes ◽  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Storage

Enhance the Thermal Storage of Cement-Based Composites With Phase Change Materials and Carbon Nanotubes

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Baoguo Han ◽  
Kun Zhang ◽  
Xun Yu
Keyword(s):  
Carbon Nanotubes ◽  
Phase Change ◽  
Building Materials ◽  
Phase Change Materials ◽  
Cement Mortar ◽  
Construction Materials ◽  
Thermal Storage ◽  
Building Models ◽  
Scale Down ◽  
Mechanical Performances

Phase change materials (PCM) have been incorporated with cementitious construction materials to store thermal energy and control interior climate in buildings, which can reduce the energy consumption and improve thermal comfort. However, addition of PCM is found to decrease strength and thermal conductivity of the cement-based composite. Carbon nanotubes (CNT) are integrated into cementitious construction materials with microencapsulated PCM to improve their thermal-conductive and mechanical performances. Results of lab and outdoor tests show the modified cement mortar containing both PCM and CNT exhibits better heat insulation properties than plain cement mortar. A temperature difference up to 6.8 °C was observed between interiors of two same size scale-down building models (one made of plain cement mortar, the other one made of cement mortar with PCM and CNT). This indicates that the modified cement mortar can effectively enhance the thermal storage property of cement-based building materials.

scholarly journals Special Issue “Advanced Phase Change Materials for Thermal Storage”

2021 ◽  
Vol 11 (4) ◽  
pp. 1390
Author(s):  
Rocío Bayón
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Thermal Storage ◽  
Research Topic ◽  
Special Issue ◽  
Advanced Phase

Thermal energy storage using phase change materials (PCMs) is a research topic that has attracted much attention in recent decades [...]

Microencapsulation of Al-Zn alloy as phase change materials for high-temperature thermal storage application

2021 ◽  
pp. 131208
Author(s):  
Qinglin Li ◽  
Xiaodong Ma ◽  
Xiaoyu Zhang ◽  
Jiqiang Ma ◽  
Xiaowu Hu ◽  
...  
Keyword(s):  
High Temperature ◽  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Storage ◽  
Zn Alloy

scholarly journals A Unique Strategy for Polyethylene Glycol/Hybrid Carbon Foam Phase Change Materials: Morphologies, Thermal Properties, and Energy Storage Behavior

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2011 ◽  
Author(s):  
Xiaolong Su ◽  
Shikui Jia ◽  
Guowei Lv ◽  
Demei Yu
Keyword(s):  
Carbon Nanotubes ◽  
Polyethylene Glycol ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Carbon Foam ◽  
Chemical Structures ◽  
Walled Carbon Nanotubes ◽  
Hybrid Carbon

Polyethylene glycol (PEG)/hybrid carbon foam (CF) phase change materials (PCMs) were prepared by integrating PEG into CF via dynamic-vacuum impregnation. The hybrid CF was first synthesized by mixtures of graphene oxide (GO) and carbon nanotubes (CNTs) with different volume ratios. The morphologies, chemical structures, thermal conductivities, shape-stabilization levels, and photo-thermal energy conversion levels of these composite PCMs were characterized systematically. The prepared composite PCMs exhibited good shape-stabilization levels and showed their original shapes without any PEG leakage. It was found that the polyethylene glycol/carbon foam with multi-walled carbon nanotubes (PEG/MCF) composite PCMs had a better shape-stable performance below the temperature of 250 °C, and the thermal conductivity of the PEG/MCF composite PCMs reached as high as 1.535 W/(mK), which was obviously higher than that of polyethylene glycol/carbon foam with single-walled carbon nanotubes (PEG/SCF, 1.159 W/(mK)). The results of the photo-thermal simulation tests showed that the composite PCMs had the ability to absorb light energy and then convert it to thermal energy, and the maximum thermal energy storage efficiency of the PEG/MCF composite PCMs and the PEG/SCF composite PCMs was 92.1% and 90.6%, respectively. It was considered that a valuable technique to produce high-performance composite PCMs was developed.

scholarly journals Charging-discharging characteristics of macro-encapsulated phase change materials in an active thermal energy storage system for a solar drying kiln

2017 ◽  
Vol 21 (6 Part A) ◽  
pp. 2525-2532 ◽  
Author(s):  
Shailendra Kumar ◽  
Kishan Kumar
Keyword(s):  
Phase Change ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Storage System ◽  
Thermal Storage ◽  
Water Tank ◽  
Solar Drying ◽  
Solidification Temperature ◽  
Water Storage Tank ◽  
Melting And Solidification

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.

scholarly journals Performance Improvement of a Household Refrigerator using Phase Change Material

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.

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

Materials ◽  
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.

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

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

Sign in / Sign up

Export Citation Format

Share Document