scholarly journals The Impact of a Mobile Shading System and a Phase-Change Heat Store on the Thermal Functioning of a Transparent Building Partition

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2512
Author(s):  
Michał Musiał ◽  
Lech Lichołai
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Summer Period ◽  
Heat Accumulator ◽  
Climate Conditions ◽  
Empirical Results ◽  
The Impact ◽  
Change Material

The article presents the results of multi-month field tests and numerical analyses describing the thermal functioning of mobile shading systems for building windows containing a phase-change heat accumulator. The experiments were conducted in the summer period with temperate climate conditions in Rzeszów (Poland). The tested shading system was dedicated to the daily life cycle of residents, taking into account both the need to illuminate the rooms with natural light and reducing the undesirable overheating of the rooms in the summer. The obtained empirical results showed a reduction in room overheating in the summer period by 29.4% from composite windows with a phase-change heat accumulator and a mobile shading system as compared to the reference composite window with an analogous mobile shading system. The database of empirical results allowed for the creation and verification of a numerical model of heat conversion, storage and distribution within the composite window containing phase change material and a mobile shading system. The verified model made it possible to analyse the thermal functioning of the modified transparent partitions in cool temperate, temperate and subtropical climates. The article is a solution to the problem of undesirable overheating of transparent building partitions by efficient storage and distribution of solar radiation energy thanks to the use of a mobile shading system and a phase change material, while presenting a useful tool enabling the prediction of energy gains in different climatic conditions.

scholarly journals Experimental Analysis of the Function of a Window with a Phase Change Heat Accumulator

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3647
Author(s):  
Lech Lichołai ◽  
Michał Musiał
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Eutectic Mixture ◽  
Field Tests ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Mathematical Tool ◽  
Heat Accumulator ◽  
Empirical Results ◽  
Explicit Finite Difference

The article presents the results of long-term field tests and their mathematical analysis regarding the impacts of innovative phase change materials on the energy efficiency of composite windows with various glazing parameters. Research was conducted on six glazing combinations throughout the heating season in a temperate climate in Rzeszów (Poland). The empirical results obtained during the spring months showed an improvement in the monthly heat balance for windows with phase change materials compared to the reference window by as much as 34.09%. In addition, the empirical results allowed the development and verification of a mathematical model describing the transport and distribution of heat within a window with a phase change heat accumulator. The model was made using equations of non-stationary heat flow and an explicit finite difference method using calorimetric thermograms describing the phase change eutectic mixture used in the research. Carrying out the Snedecor–Fischer test proved the statistical adequacy of the developed model in 4 out of 6 tested combinations of glazing units. Good matching of the empirical and theoretical quantities was also confirmed using the quasi-Newton method. The article is a solution to the problem of the effective use of solar energy within transparent building partitions, while presenting a useful mathematical tool that determines potential thermal gains in various climatic conditions.

Experimental Investigation and Numerical Modeling of Room Temperature Control in Buildings by the Implementation of Phase Change Material in the Roof

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
N. Beemkumar ◽  
D. Yuvarajan ◽  
M. Arulprakasajothi ◽  
S. Ganesan ◽  
K. Elangovan ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Phase Change ◽  
Layer Thickness ◽  
Phase Change Material ◽  
Energy Demand ◽  
Model Building ◽  
Climatic Conditions ◽  
Air Conditioners ◽  
The Impact ◽  
Change Material

Abstract Due to the increasing demand for air conditioners to maintain thermal comfort in buildings, it is necessary to search for alternatives that can reduce the soaring temperature and meet total air conditioning demands. There are several proven technologies for maintaining thermal comfort in buildings of which the use of phase change material (PCM) in buildings provides improved thermal comfort with fewer energy requirements. The present study analyzes the impact of the incorporation of PCM in roofs on the thermal behavior of buildings. The experiments were conducted in two identical model building roofs with and without the implementation of PCM. A numerical model was developed to find the effect of variation in the PCM layer thickness and month wise temperature variations. To get minimum variation in the results, the simulation was run continuously for 5 days assuming average climatic conditions. The results showed that temperature fluctuations in the room were reduced with the use of PCM, and also the average peak temperature rise was reduced by 2–4°C. The increased PCM layer thickness resulted in decreased energy demand for maintaining the required thermal comfort in buildings at an almost constant temperature.

scholarly journals Numerical Simulation of the Impact of the Heat Source Position on Melting of a Nano-Enhanced Phase Change Material

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1425
Author(s):  
Tarek Bouzennada ◽  
Farid Mechighel ◽  
Kaouther Ghachem ◽  
Lioua Kolsi
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Numerical Study ◽  
Melting Rate ◽  
Heat Transfer Fluid ◽  
Commercial Code ◽  
Tube Position ◽  
The Impact ◽  
Change Material

A 2D-symmetric numerical study of a new design of Nano-Enhanced Phase change material (NEPCM)-filled enclosure is presented in this paper. The enclosure is equipped with an inner tube allowing the circulation of the heat transfer fluid (HTF); n-Octadecane is chosen as phase change material (PCM). Comsol-Multiphysics commercial code was used to solve the governing equations. This study has been performed to examine the heat distribution and melting rate under the influence of the inner-tube position and the concentration of the nanoparticles dispersed in the PCM. The inner tube was located at three different vertical positions and the nanoparticle concentration was varied from 0 to 0.06. The results revealed that both heat transfer/melting rates are improved when the inner tube is located at the bottom region of the enclosure and by increasing the concentration of the nanoparticles. The addition of the nanoparticles enhances the heat transfer due to the considerable increase in conductivity. On the other hand, by placing the tube in the bottom area of the enclosure, the liquid PCM gets a wider space, allowing the intensification of the natural convection.

scholarly journals Latent Heat Thermal Storage of Nano-Enhanced Phase Change Material Filled by Copper Foam with Linear Porosity Variation in Vertical Direction

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1508
Author(s):  
Mohammad Ghalambaz ◽  
Mohammad Shahabadi ◽  
S. A. M Mehryan ◽  
Mikhail Sheremet ◽  
Obai Younis ◽  
...  
Keyword(s):  
Natural Convection ◽  
Phase Change ◽  
Phase Change Material ◽  
Metal Foam ◽  
Vertical Direction ◽  
Melting Time ◽  
Copper Foam ◽  
Average Porosity ◽  
The Impact ◽  
Change Material

The melting flow and heat transfer of copper-oxide coconut oil in thermal energy storage filled with a nonlinear copper metal foam are addressed. The porosity of the copper foam changes linearly from bottom to top. The phase change material (PCM) is filled into the metal foam pores, which form a composite PCM. The natural convection effect is also taken into account. The effect of average porosity; porosity distribution; pore size density; the inclination angle of enclosure; and nanoparticles’ concentration on the isotherms, melting maps, and the melting rate are investigated. The results show that the average porosity is the most important parameter on the melting behavior. The variation in porosity from 0.825 to 0.9 changes the melting time by about 116%. The natural convection flows are weak in the metal foam, and hence, the impact of each of the other parameters on the melting time is insignificant (less than 5%).

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
Keyword(s):  
Thermal Comfort ◽  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Chemical Change ◽  
Thermal Inertia ◽  
Temperature Fluctuations ◽  
High Energy ◽  
Climate Conditions ◽  
Change Material

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.

A Methodology of an Automotive Engine Cooling Using a Phase Change Material

2009 ◽  
Author(s):  
Kibum Kim ◽  
Kyung-wook Choi ◽  
Ki-hyung Lee ◽  
Kwan-soo Lee
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Heat Load ◽  
Cooling System ◽  
Heat Accumulator ◽  
Full Size ◽  
Automotive Engine ◽  
Excessive Heat ◽  
Engine Cooling ◽  
Change Material

The size of a cooling inventory is generally designed based on which size can endure the excessive heat load situations that occur sporadically. As a result, cooling systems are often too large for most normal driving modes. There have been numerous efforts to downsize the automotive engine cooling system using novel concepts and strategies (e.g. THEMIS cooling system, CoolMaster, UltimateCooling). However, in terms of the system design, preserving the passive cooling strategy may be simpler and more practical than implementing any major changes. Vetrovec (2008) proposed the use of a heat accumulator that has a phase change material (PCM) within the automotive cooling system. Excessive heat generated during severe operating conditions is stored in the heat accumulator, and it is dissipated during periods of low heat load. The heat dissipation capacity of the radiator and the amount of coolant in the cooling system are normally designed such that the system can sustain itself at peak heat load during acceleration and hill ascents in hot summer periods. Therefore, the unnecessarily large cooling inventory creates an overloaded vehicle which increases the fuel consumption rate. A heat accumulator which averages out the peak heat loads can reduce the entire cooling system remarkably in terms of both its volume and weight. Effective cooling in automobiles is beneficial in reducing harmful emissions as well as improving fuel economy. A simulation was conducted to validate the feasibility of using a novel cooling strategy that utilized the heat load averaging capabilities of a phase change material (PCM). Three prototypes were designed: full size, down sized, and a down sized prototype with a heat accumulator containing the PCM inside. When the full size of the cooling inventory was downsized by 30%, this smaller design failed to dissipate the peak heat load and consequently led to a significant increase in the coolant temperature, around 25 °C greater than that in the full size system. However, the peak heat load was successfully averaged out in the downsized system with a heat accumulator. Experimental study is also on-going to validate the simulation results and find more suitable PCM for the application.

Sign in / Sign up

Export Citation Format

Share Document