scholarly journals Effect of phase change material using in building thermal comfort applications through several climate conditions.

2020 ◽  
Vol 170 ◽  
pp. 01007
Author(s):  
Marwa El Yassi ◽  
Ikram El Abbassi ◽  
Alexandre Pierre ◽  
Yannick Melinge

Nowadays, buildings sector contributes to climate change by consuming a considerable amount of energy to afford thermal comfort for occupants. Passive cooling techniques are a promising solution to increase the thermal inertia of building envelopes, and reduce temperature fluctuations. The phase change materials, known as PCM, can be efficiently employed to this purpose, because of their high energy storage density. Among the various existing solutions, the present study is dedicated to solid-liquid phase change materials. Temperature evolution (according to their defined temperature range) induces the chemical change of the material and its state. For building applications, the chemical transition can be accomplished from liquid to solid (solidification) and from solid to liquid (melting). In fact, this paper presents a comparative thermal analysis of several test rooms with and without phase change materials embedded in a composite wallboard in different climates. The used PCM consist in a flexible sheet of 5 mm thickness (Energain, manufactured by the company DuPont de Nemours). The main properties of such a commercial solution have been delivered by the manufacturer and from analyses. The room model was validated using laboratory instrumentations and measurements of a test room in four cities: Lyon; Reading and Casablanca. Results indicate that this phase change material board can absorb heat gains and also reduce the indoor air temperature fluctuations during daytime. The aim of the study is to show the benefits of this layer with phase change material and compare it in different climatic zones.

Author(s):  
Justin Hollis ◽  
Darin J Sharar ◽  
Todd Bandhauer

Abstract High temperature silicon carbide (SiC) die are the most critical and expensive component in electric vehicle (EV) power electronic packages and require both active and passive methods to dissipate heat during transient operation. The use of phase change materials (PCMs) to control the peak junction temperature of the SiC die and to buffer the temperature fluctuations in the package during simulated operation is modeled here. The latent heat storage potential of multiple PCM and PCM composites are explored in both single-sided and dual-sided package configurations. The results of this study show that the addition of phase change material (PCM) into two different styles of power electronics (PE) packages is an effective method for controlling the transient junction temperatures experienced during two different drive cycles. The addition of PCM in a single-sided package also serves to decrease temperature fluctuations experienced and may be used to reduce the necessary number of SiC die required for EVs, lowering the overall material cost and volume of the package by over 50%. PCM in a single-sided package may be nearly as effective as the double-sided cooling approach of a dual-sided package in the reduction of both peak junction temperature of SiC as well as controlling temperature variations between package layers.


2020 ◽  
pp. 174425912094536 ◽  
Author(s):  
Amal Louanate ◽  
Rabie El Otmani ◽  
Khalid Kandoussi ◽  
M’Hamed Boutaous

Nowadays, latent heat storage is becoming an imperative in building sector since it plays a crucial role in conserving energy through controlling the thermal comfort level. In this field, different storage systems based on phase change material show great performances in terms of energy saving, leading to a significant improvement of occupant thermal comfort. In this work, the thermal behavior and energy efficiency of a residential house incorporating various phase change materials (RT18HC, RT21HC, RT25HC, and RT28HC) in Mediterranean climate region were investigated via numerical simulations. EnergyPlus software was used to analyze the thermal performance of phase change materials applied to the interior wall surfaces of a simplified building model in El Jadida city. The integration of different single and double phase change material layers has been evaluated based on various concepts such as the average temperature fluctuation reduction and the monthly energy saving. The study showed that low melting point phase change material outperforms in terms of heating load, while phase change material with high melting temperature favors the cooling performance. Moreover, the results show that double-layer systems formed by two distinct phase change materials exhibit higher performance than a single phase change material layer throughout the whole year. The annual energy saving rate reaches 41.42% and 55.41% when using single and double phase change material layers, respectively. Finally, we opted for an optimum double-layer system for lower energy consumption in the selected city.


2020 ◽  
Vol 330 ◽  
pp. 01043
Author(s):  
Chihebedine Beji ◽  
Sami Bouzaiane ◽  
Nahla Bouaziz

The growing energy consumption of the building sector is becoming a current issue affecting both environmental and economical fields. The present paper investigates thermal comfort conditions inside the manuscript room of the National library of Tunisia by using an IoT based smart measuring system. The tracked parameters are temperature and relative humidity. These parameters are considered as the fundamental factors influencing thermal comfort inside a building. The results of this survey performed during the month of January 2019 lead us to propose an energy optimization measure, in order to update heating system electricity consumption. The proposed approach consists of the use of phase change materials (PCM) window shutters. PCM window shutters can act as thermal regulators thanks to their melting solidification process. The results of the proposed solution showed that adopting PCM window shutters for the examined test room can save up to 10% for the first phase change material and 15% for the second phase change material of the total energy used by the heat pump unit to maintain the inside air temperature at 21°C.


2010 ◽  
Vol 7 (2) ◽  
pp. 79-89 ◽  
Author(s):  
Mustapha Faraji

This work describes and analyses a novel computer's thermal management system based on a phase change material (PCM) heat storage reservoir. The proposed heat sink consists of a PCM filled enclosure heated by substrate-mounted protruding heat sources (micro processors). PCMs, characterized by high energy storage density and small transition temperature interval, are able to store a high amount of generated heat; which provides a passive cooling of microprocessors. The advantage of this cooling strategy is that the phase change materials are able to absorb a high amount of generated heat without energizing the fan. The proposed strategy is suitable and efficient for situations where the cooling by air convection is not practical (thermal control of recent multiprocessors computers, for example). The problem is modelled as, two dimensional, time dependent and convection–dominated phenomena. A finite volume numerical approach is developed and used to simulate the physical details of the problem. This approach is based on the enthalpy method which is traditionally used to track the motion of the liquid/solid front and obtain the temperature and velocity profiles in the liquid phase. The study gives an instruction on the presentation of PCM heat sink used for cooling management of recent computers. Numerical investigations have been conducted in order to examine the impact of several parameters on the thermal behaviour and efficiency of the proposed PCM-based heat sink. Correlation for the secured operating time (time required by the heat sink before reaching the critical temperature, Tcr) is developed.


Author(s):  
Mr. Omkar Jadhav

An experimental study using paraffin wax as a phase change material (PCM) was performed to analyse thermal physiognomies on the latent heat storage system (LHS). The use of phase change materials through latent heat storage is an unusual approach to maintaining thermal energy. There is the advantage of considerably high energy storage and the uniform temperature of the storage process. Tube & shell type heat exchanger (HE) has been used in this experimentation. Water circulates in tubes and around the tube’s paraffin wax as phase change material is filled. The focus is on heating (charging) and cooling (discharging) of PCM (paraffin wax), which is the melting and solidifying of paraffin wax. The temperature distribution in paraffin is studied consistent with the various flow rates of the warmth transfer fluid.


2021 ◽  
Vol 294 ◽  
pp. 04002
Author(s):  
Kunlun Li

Phase change materials can not only save thermal storage, but also improve residential thermal comfort. In this paper, the finite element software COMSOL is used to simulate the effect of phase change material wallboards on the improvement of residential comfort in the urban village of Guangzhou, China. The results clearly show that the use of phase change material wallboards has a positive influence on the indoor thermal comfort of the urban village.


2021 ◽  
Vol 2069 (1) ◽  
pp. 012005
Author(s):  
A.M. Omeme Ada ◽  
A. D. Tran Le ◽  
H. Toifane ◽  
P. Tittelein ◽  
L. Zalewski ◽  
...  

Abstract The use of biobased materials in building construction allows the reduction of fossil resource use and energy consumption. Among biobased materials, hemp lime concrete has been investigated in many studies highlighting its capacity to regulate interior relative humidity and its high insulation capacity. In order to design high-performance biobased concretes, a new hemp lime concrete combining the hygric regulation capacity of hemp lime concrete with the thermal regulation performance of phase change material was developed. This article focuses on the thermal and hygric performance of the new hemp lime concretes incorporating micro-capsulated phase change material (PCM) (named HL-PCM). Three hemp lime concretes that differ from formulation were developed and investigated. The thermal properties, moisture buffer values and its impact on interior relative humidity variation have been presented. Thanks to experimental works and numerical simulations, the results obtained showed that the thermal conductivity remain low, the heat capacity and thermal inertia increase considerably for hemp concrete with PCM, while the moisture buffering capacity remains excellent. Finally, numerical results showed that the used of hemp lime concrete (with and without PCM) reduce indoor relative humidity variation and improve indoor hygrothermal comfort.


Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 41
Author(s):  
Hanae El Fakiri ◽  
Lahoucine Ouhsaine ◽  
Abdelmajid El Bouardi

The thermal dynamic behavior of buildings represents an important aspect of the energy efficiency and thermal comfort of the indoor environment. For this, phase change material (PCM) wallboards integrated into building envelopes play an important role in stabilizing the temperature of the human comfort condition. This article provides an assessment of the thermal behavior of a “bi-zone” building cell, which was built based on high-energy performance (HEP) standards and heated by a solar water heater system through a hydronic circuit. The current study is based on studying the dynamic thermal behavior, with and without implantation of PCMs on envelope structure, using a simplified modeling approach. The evolution of the average air temperature was first evaluated as a major indicator of thermal comfort. Then, an evaluation of the thermal behavior’s dynamic profile was carried out in this study, which allowed for the determination of the PCM rate anticipation in the thermal comfort of the building cell.


Author(s):  
A. Castell ◽  
C. Sole´ ◽  
M. Medrano ◽  
M. Nogue´s ◽  
L. F. Cabeza

Most of the storage systems available on the market use water as storage medium. Enhancing the storage performance is necessary to increase the performance of most systems. The stratification phenomenon is employed to improve the efficiency of storage tanks. Heat at an intermediate temperature, not high enough to heat up the top layer, can still be used to heat the lower, colder layers. There are a lot of parameters to study the stratification in a water tank such as the Mix Number and the Richardson Number among others. The idea studied here was to use these stratification parameters to compare two tanks with the same dimensions during charging and discharging processes. One of them is a traditional water tank and the other is a PCM-water (a water tank with a Phase Change Material). A PCM is good because it has high energy density if there is a small temperature change, since then the latent heat is much larger than the sensible heat. On the other hand, the temperature change in the top layer of a hot water store with stratification is usually small as it is held as close as possible at or above the temperature for usage. In the system studied the Phase Change Material is placed at the top of the tank, therefore the advantages of the stratification still remain. The aim of this work is to demonstrate that the use of PCM in the upper part of a water tank holds or improves the benefit of the stratification phenomenon.


Author(s):  
Ali Deriszadeh ◽  
Filippo de Monte ◽  
Marco Villani

Abstract This study investigates the cooling performance of a passive cooling system for electric motor cooling applications. The metal-based phase change materials are used for cooling the motor and preventing its temperature rise. As compared to oil-based phase change materials, these materials have a higher melting point and thermal conductivity. The flow field and transient heat conduction are simulated using the finite volume method. The accuracy of numerical values obtained from the simulation of the phase change materials is validated. The sensitivity of the numerical results to the number of computational elements and time step value is assessed. The main goal of adopting the phase change material based passive cooling system is to maintain the operational motor temperature in the allowed range for applications with high and repetitive peak power demands such as electric vehicles by using phase change materials in cooling channels twisted around the motor. Moreover, this study investigates the effect of the phase change material container arrangement on the cooling performance of the under study cooling system.


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