EFFECTS OF DIFFERENT THERMAL CONDUCTIVITY ENHANCERS ON THE THERMAL PERFORMANCE OF TWO ORGANIC PHASE-CHANGE MATERIALS: PARAFFIN WAX RT42 AND RT25

2013 ◽  
Vol 20 (6) ◽  
pp. 463-473 ◽  
Author(s):  
Yongcai Li ◽  
Shuli Liu
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Organic Phase ◽  
Thermal Performance ◽  
Phase Change Materials ◽  
Paraffin Wax

scholarly journals Role of Phase Change Materials Containing Carbonized Rice husks on the Roof-Surface and Indoor Temperatures for Cool Roof System Application

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3280
Author(s):  
Hong Gun Kim ◽  
Yong-Sun Kim ◽  
Lee Ku Kwac ◽  
Mira Park ◽  
Hye Kyoung Shin
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Paraffin Wax ◽  
Heat Absorption ◽  
Rice Husks ◽  
Indoor Temperature ◽  
Cool Roof ◽  
Plastic Composites

This study researches the effect of phase change materials (PCMs) containing carbonized rice husks (CRHs) in wood plastic composites (WPCs) as roof finishing materials on roof-surface and indoor temperatures. A cool roof miniature model was prepared, and measurements were taken using three fixed temperatures of 30 to 32 °C, 35 to 37 °C, and 40 to 42 °C. Sodium sulfate decahydrate (Na2SO4·10H2O) and paraffin wax were selected as the PCMs. CRHs were used as additives to improve the thermal conductivities of the PCMs. At lower fixed temperatures such as 30 to 32 °C and 35 to 37 °C, the rates of increase of the surface temperatures of roofs containing CRHs with Na2SO4·10H2O, and paraffin wax, were observed to gradually decrease compared to those of the roofs without PCMs. The indoor temperatures for the above-mentioned PCMs containing CRHs were maintained to be lower than those of the indoors without PCMs. Additionally, as the CRH content in the PCM increased, the rates of increase of the roof-surface and indoor temperatures decreased due to a faster roof heat absorption by PCMs through the improved thermal conductivity of CRHs. However, under higher artificial temperatures such as 40 to 42 °C, Na2SO4·10H2O with CRHs exhibited no effect due to being out of latent heat range of Na2SO4·H2O. For paraffin wax, as CRH content increased, their roof- surface and indoor temperatures decreased. Especially, the surface temperature of the roof containing paraffin contained 5 wt.% CRHs reduced by 11 °C, and its indoor temperature dropped to 26.4 °C. The thermal conductivity of PCM was enhanced by the addition of CRHs. A suitable PCM selection in each location can result in the reduction of the roof-surface and indoor temperatures.

1,3:2,4-di-(3,4-dimethyl)benzylidene sorbitol organogels used as phase change materials: solvent effects on structure, leakage and thermal performance

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21733-21739 ◽  
Author(s):  
Libo Niu ◽  
Guoyi Bai ◽  
Jian Song
Keyword(s):  
Phase Change ◽  
Molecular Mass ◽  
Organic Phase ◽  
Thermal Performance ◽  
Solvent Effects ◽  
Phase Change Materials ◽  
Stable Phase

Organogels used as shape-stable phase change materials were prepared by impregnating a low molecular mass organogelator into organic phase change materials.

scholarly journals Preparation and Thermal Performance Enhancement of Low Temperature Eutectic Composite Phase Change Materials Based on Na2SO4·10H2O

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2230 ◽  
Author(s):  
Pumin Hou ◽  
Jinfeng Mao ◽  
Fei Chen ◽  
Yong Li ◽  
Xian Dong
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Thermal Performance ◽  
Phase Change Materials ◽  
Performance Enhancement ◽  
Expanded Graphite ◽  
Nucleating Agent ◽  
Thermal Reliability ◽  
Composite Phase Change Materials ◽  
Mass Fractions

In this paper, a series of Na2SO4·10H2O–KCl eutectic mixtures were prepared by adding different mass fractions of KCl (1 wt.%, 3 wt.%, 5 wt.%, or 7 wt.%) to Na2SO4·10H2O. Polyacrylamide (PAM) was proposed as the thickener, sodium tetraborate decahydrate (STD) was proposed as the nucleating agent, and expanded graphite (EG) was proposed as the high thermal conductivity medium for Na2SO4·10H2O–5 wt.% KCl eutectics. The results showed that in Na2SO4·10H2O–5 wt.% KCl eutectics with 5 wt.% PAM and 5 wt.% STD, almost no phase separation occurred, and the degree of supercooling was reduced to 0.4 °C. The thermal performance of Na2SO4·10H2O–5 wt.% KCl composite phase change materials (CPCMs) with varying contents of EG was explored. The results showed that EG could improve the thermal conductivity effectively and that the mass fraction of EG should be no more than 3%, otherwise the crystallization value and supercooling would deteriorate. The thermal reliability of the Na2SO4·10H2O–5 wt.% KCl eutectic CPCMs containing 5 wt.% PAM, 5 wt.% STD, and 3 wt.% EG was investigated, mainly through the ambient temperature, thermal cycling test, and TGA analysis. The results demonstrated that these CPCMs showed perfect thermal reliability.

Leakage-proof phase change composites supported by biomass carbon aerogels from succulents

2018 ◽  
Vol 20 (8) ◽  
pp. 1858-1865 ◽  
Author(s):  
Yanhong Wei ◽  
Juanjuan Li ◽  
Furong Sun ◽  
Jinrong Wu ◽  
Lijuan Zhao
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Organic Phase ◽  
Phase Change Materials ◽  
Carbon Aerogels ◽  
Biomass Carbon ◽  
Low Thermal Conductivity ◽  
Practical Applications ◽  
Phase Change Composites

The practical applications of organic phase change materials (PCM) are greatly limited, due to their leakage in the melted state and unacceptably low thermal conductivity.

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