scholarly journals Numerical Analysis of Building Envelope with Movable Phase Change Materials for Heating Applications

2019 ◽  
Vol 9 (18) ◽  
pp. 3688
Author(s):  
Alvaro de Gracia
Keyword(s):  
Numerical Analysis ◽  
Phase Change ◽  
Phase Change Materials ◽  
Building Envelope ◽  
Space Heating ◽  
Passive Heating ◽  
Latent Heat Storage ◽  
Heating And Cooling ◽  
Design Variables ◽  
Heat Storage Materials

Latent heat storage materials have been tested by several researchers for decades to be used as passive heating and cooling systems in buildings but their implementation into building components is still stacked as is facing specific technical limitations related to difficulties to be charged both in heating and cooling periods. This paper presents a numerical analysis to evaluate the potential of a disruptive system, which is designed to solve the main drawbacks and to convert phase change materials (PCM) passive heating technology into a competitive solution for the building sector. The novel technology moves PCM layer with respect to the insulation layer inside the building component to maximize solar benefits in winter and be able to actively provide space heating. Design variables such as PCM melting point and control schemes were optimized. The results demonstrated that this technology is not only able to limit heat losses towards outdoors but it can provide space heating from stored solar energy when required. The promising numerical results endorse the possibility to build a future experimental prototype to quantify more in detail the benefits of this system.

Latent Heat Storage Plaster: Lab-Scale Experiment and Simulation

2014 ◽  
Vol 1077 ◽  
pp. 124-128
Author(s):  
Milan Ostrý ◽  
Pavel Charvát ◽  
Tomáš Klubal ◽  
Lubomír Klimeš
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Heat Storage ◽  
High Heat ◽  
Latent Heat Storage ◽  
Heating And Cooling ◽  
Scale Experiment ◽  
Building Operation

Energy storage can even out mismatches between the demand and supply of energy, thereby improving the system performance and reducing the cost of building operation. The energy storage is a key issue in the wider use of renewable energy. The experiments carried out at Brno University of Technology focus on the latent heat storage techniques for application in radiant heating and cooling of residential and office buildings. The latent heat storage techniques utilize Phase Change Materials (PCMs) as a heat storage medium and thus allow for the reduction of the amount of heat storage material due to the high heat storage density per volume or weight. In the past, much attention was paid to encapsulation of PCMs. The PCMs undergo phase change from solid to liquid and vice versa during a heat storage cycle and there is a risk of leakage of the PCMs to the building material or indoor environment. The microencapsulated organic PCMs in a mixture with gypsum plaster were used in the investigations described in this paper. The investigations involved both lab-scale experiments and numerical simulations.

scholarly journals Evaluation of the Performance of a Building Envelope Constructed with Phase-Change Materials in Relation to Orientation in Different Climatic Regions

2019 ◽  
Vol 111 ◽  
pp. 04003
Author(s):  
Eda Köse ◽  
Gülten Manioğlu
Keyword(s):  
Energy Consumption ◽  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Climatic Regions ◽  
Heating And Cooling ◽  
Energy Consumptions ◽  
Change Material

Minimizing the effect of climatic conditions and energy consumption in buildings are important issues to be considered in the building design process. Due to the changes in climatic conditions, there is an increase not only in the consumption of heating energy but also cooling energy. Certain passive measures to be taken primarily for the building envelope are necessary in order to reduce energy consumption. Applying a phase-change material on the surface of a building envelope is one of the new approaches for controlling heat transfer through the building envelope during the cooling period. It is known that phase-change materials, which are also considered as modern versions of thermal mass concept, can reduce the of a building’s heating and cooling energy consumption. In this study, a unit with 10m to 10m dimension with one external facade in a 3 storey building was evaluated in two cities, Istanbul and Diyarbakır, in temperate-humid and hot dry climatic regions. In order to reduce heating and cooling loads, a phase-change material was applied on the surface of the building envelope. The thickness of the phase-change material on the applied surface was increased at every step, and different building envelope alternatives were created. Heating and cooling energy consumptions were calculated for different orientations of the external facade. When calculated values are evaluated comparatively, it is seen that as the thickness of the phase-change material increases, the energy loads occurred in the unit decrease gradually. Equally, the performance of the phase-change materials varies depending on the orientation. Therefore, it is possible to determine the optimum thickness and orientation combination of the phase-change material application on a building envelope and reduce heating and cooling energy consumptions.

Novel PCM-based coating for thermal management of high temperature electronic assemblies

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000091-000095 ◽  
Author(s):  
A. Novikov ◽  
C. Strehse ◽  
D. Lexow ◽  
M. Nowottnick
Keyword(s):  
High Temperature ◽  
Phase Change ◽  
Thermal Management ◽  
Phase Change Materials ◽  
Electronic Components ◽  
Latent Heat Storage ◽  
Worst Case ◽  
Fully Integrated ◽  
Selective Coating ◽  
Heat Storage Materials

The electronic components are exposed nowadays increasingly higher temperatures. On one site the power density is increasing and on the other site the electronic appliances are used in more and more harsh environments with high temperature loads. In worst case the combination of both can quickly lead to exceeding the critical temperature resulting in damage and total failure. There are a lot of investigations to increase the robustness of certain elements, like semiconductor and packaging materials, interconnections and PCB. Another approach for increasing the reliability of power electronic modules is the development of sophisticated thermal management system. Traditional cooling methods are coming up to their limits in high integrated electronic modules. A possible solution is the use of latent heat storage materials (PCM - phase change materials), which can be fully integrated into a compliant selective coating of critical electronic components [1], [2]. During phase change process the temperature peaks can be effectively smoothed by adsorbing and releasing the heat. This results directly in increasing of number of cycles until end of life.

Selection of Phase Change Materials for Latent Heat Storage

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
J. Martínez-Gómez ◽  
E. Urresta ◽  
D. Gaona ◽  
G. Guerrón
Keyword(s):  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Latent Heat Storage ◽  
Toma De Decisiones ◽  
Selection Of

Esta investigación tiene como objetivo seleccionar un material de cambio de fase (PCM) que cumplen mejor la solución del almacenamiento de energía térmica entre 200-400 ° C y reducir el costo de producción. El uso de métodos multicriterios de toma de decisiones (MCMD) para la evaluación fueron proporcionales implementados como COPRAS-G, TOPSIS y VIKOR. La ponderación de los criterios se realizó por el método AHP (proceso analítico jerárquico) y los métodos de entropía. La correlación de los resultados entre los tres métodos de clasificación ha sido desarrollada por el coeficiente de correlación de Spearman. Los resultados ilustran el mejor y la segundo mejor opción para los tres MCDM fueron NaOH y KNO3. Además, tenía valores de correlación de Spearman entre los métodos excede de 0.714.

scholarly journals Encapsulation of Phase Change Materials Using Layer-by-Layer Assembled Polyelectrolytes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Qiangying Yi ◽  
Gleb B. Sukhorokov ◽  
Jin Ma ◽  
Xiaobo Yang ◽  
Zhongwei Gu
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Low Cost ◽  
Sodium Dodecyl ◽  
Layer By Layer ◽  
Latent Heat Storage ◽  
Good Thermal Stability ◽  
Lbl Assembly ◽  
Acid Sodium Salt ◽  
Assembly Technique

Phase change materials absorb the thermal energy when changing their phases (e.g., solid-to-liquid) at constant temperatures to achieve the latent heat storage. The major drawbacks such as limited thermal conductivity and leakage prevent the PCMs from wide application in desired areas. In this work, an environmentally friendly and low cost approach, layer-by-layer (LbL) assembly technique, was applied to build up ultrathin shells to encapsulate the PCMs and therefore to regulate their changes in volume when the phase change occurs. Generally, the oppositely charged strong polyelectrolytes Poly(diallyldimethylammonium chloride) (PDADMAC) and Poly(4-styrenesulfonic acid) sodium salt (PSS) were employed to fabricate multilayer shells on emulsified octadecane droplets using either bovine serum albumin (BSA) or sodium dodecyl sulfate (SDS) as surfactant. Specifically, using BSA as the surfactant, polyelectrolyte encapsulated octadecane spheres in size of ∼500 nm were obtained, with good shell integrity, high octadecane content (91.3% by mass), and good thermal stability after cycles of thermal treatments.

scholarly journals Experimental Characterization of Phase Change Materials for Refrigeration Processes

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3033
Author(s):  
Anastasia Stamatiou ◽  
Lukas Müller ◽  
Roger Zimmermann ◽  
Jamie Hillis ◽  
David Oliver ◽  
...  
Keyword(s):  
Energy Density ◽  
Phase Change ◽  
Thermophysical Properties ◽  
Phase Change Materials ◽  
Cost Effective ◽  
Latent Heat Storage ◽  
Lower Energy Density ◽  
Change Material ◽  
Storage Units

Latent heat storage units for refrigeration processes are promising as alternatives to water/glycol-based storage due to their significantly higher energy densities, which would lead to more compact and potentially more cost-effective storages. In this study, important thermophysical properties of five phase change material (PCM) candidates are determined in the temperature range between −22 and −35 °C and their compatibility with relevant metals and polymers is investigated. The goal is to complement existing scattered information in literature and to apply a consistent testing methodology to all PCMs, to enable a more reliable comparison between them. More specifically, the enthalpy of fusion, melting point, density, compatibility with aluminum, copper, polyethylene (PE), polypropylene (PP), neoprene and butyl rubber, are experimentally determined for 1-heptanol, n-decane, propionic acid, NaCl/water mixtures, and Al(NO3)3/water mixtures. The results of the investigations reveal individual strengths and weaknesses of the five candidates. Further, 23.3 wt.% NaCl in water stands out for its very high volumetric energy density and n-decane follows with a lower energy density but better compatibility with surrounding materials and supercooling performance. The importance of using consistent methodologies to determine thermophysical properties when the goal is to compare PCM performance is highlighted.

scholarly journals pH-controlled synthesis of sustainable lauric acid/SiO2 phase change material for scalable thermal energy storage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shafiq Ishak ◽  
Soumen Mandal ◽  
Han-Seung Lee ◽  
Jitendra Kumar Singh
Keyword(s):  
Electron Microscopy ◽  
Phase Change ◽  
Lauric Acid ◽  
Photoelectron Spectroscopy ◽  
Phase Change Materials ◽  
Precursor Solution ◽  
Thermal Reliability ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Heating And Cooling

AbstractLauric acid (LA) has been recommended as economic, eco-friendly, and commercially viable materials to be used as phase change materials (PCMs). Nevertheless, there is lack of optimized parameters to produce microencapsulated PCMs with good performance. In this study, different amounts of LA have been chosen as core materials while tetraethyl orthosilicate (TEOS) as the precursor solution to form silicon dioxide (SiO2) shell. The pH of precursor solution was kept at 2.5 for all composition of microencapsulated LA. The synthesized microencapsulated LA/SiO2 has been characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-Ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM). The SEM and TEM confirm the microencapsulation of LA with SiO2. Thermogravimetric analysis (TGA) revealed better thermal stability of microencapsulated LA/SiO2 compared to pure LA. PCM with 50% LA i.e. LAPC-6 exhibited the highest encapsulation efficiency (96.50%) and encapsulation ratio (96.15%) through Differential scanning calorimetry (DSC) as well as good thermal reliability even after 30th cycle of heating and cooling process.

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