Numerical Investigation of a Phase Change Material Building Integrating Solar Thermal Collector PCM-BST

Author(s):  
Benkadour Ayman ◽  
Mustapha Faraji

Abstract Sensible thermal energy storage systems can reduce energy environmental fluctuation dependency with the nocturnal energy needs usage in maintaining the building's comfort levels. In the present paper, Phase Change Material (PCM) is introduced to improve the thermal energy storage capacity of a solar collector integrating a novel composite Phase Change Material (PCM)/concrete wall. A mathematical model based upon the conservation and heat transfer equations has been developed using the enthalpy method. The Numerical investigation has been implemented into a personal FORTRAN code. Many series of simulation runs were executed. The position of the PCM layer within the wall and the PCM melting temperature are varied in the range 0 cm ≤ xm ≤ 7.5 cm and 15 °C ≤ Tm ≤ 35 °C, respectively. The objective is to let inner temperature Tin swing close to a comfort threshold. The position of PCM close to the absorber improves the efficiency of the room heating with good nocturnal use of latent heat stored during the day. PCM melting temperature affects deeply the composite PCM/concrete wall/solar collector behavior. Lastly, PCM gained the system an important benefit which is the solar collector high-Temperature isolation as to not reach the room and disturb the inside comfort zone by melting and solidifying. Those parameters can be considered as the primary pointers for PCM/wall integrated solar collector design. Also, a Daily Heating Potential, Qh, and Thermal Load Leveling, TLL, are introduced to evaluate the system performance.

Author(s):  
Omid Ghahramani Zarajabad ◽  
Rouhollah Ahmadi ◽  
Saeed Ghaffari

Freezer is one of the electrical components that can be found in any building. Like any electrical appliance domestic freezer consumes a significant amount of energy during its working time. During recent decades a lot of solutions have been found to reduce this energy consumption. One of the most usable and appropriate ones is implementation of phase change material (PCM) in a Cold Thermal Energy Storage (CTES) system which can be installed in a household freezers. In this paper numerical investigation of using CTES system in a domestic freezer in order to diminish energy consumption during pick hours (18-22:30), is studied. Regard to the temperature ranges of the freezer, NaCl-H2O is used as a PCM in the CTES system. In a distinct period of time, a large amount of cold thermal energy in latent heat form is stored at low temperature in the PCM, and it is released in the freezer’s cabin when the compressor is off. Accordingly, numerical modeling and simulation using Computational Fluid Dynamics (CFD) software on charging and discharging cycle of PCM are done to measure cold storage period and amount of saved energy. The results reveal that using CTES could keep the freezer in the standard thermal condition without using a compressor, for 4.5 hours. These results show that if the PCM used in CTES system for a year, it could reduce energy, fossil fuel consumption and CO2 emission up to 45.7 kWh, 13.7 liters and 32.0 kg, respectively.


2011 ◽  
Vol 88 (7) ◽  
pp. 2454-2462 ◽  
Author(s):  
Annabelle Joulin ◽  
Zohir Younsi ◽  
Laurent Zalewski ◽  
Stéphane Lassue ◽  
Daniel R. Rousse ◽  
...  

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