Performance Enhancement of Concentrated Photovoltaic System Using Phase-Change Material

2016 ◽  
Author(s):  
Mohamed Emam ◽  
Mahmoud Ahmed ◽  
Shinichi Ookawara
Keyword(s):  
Solar Cell ◽  
Phase Change ◽  
Phase Change Material ◽  
Conversion Efficiency ◽  
Concentration Ratio ◽  
High Energy ◽  
High Concentration ◽  
Cell Temperature ◽  
Average Temperature ◽  
Change Material

The contribution of renewable energy to the worldwide sustainable development and environmental preservation has been widely recognized nowadays. Concentrated photovoltaic (CPV) system, in particular, has received an extensive research effort as one of the most promising applications of solar energy. Due to the high concentration r1atio, a significant increase in the CPV temperature occurs. Consequently, the conversion efficiency deteriorates; thereby thermal regulation of a CPV system is of great importance. Therefore, a hybrid system including CPV, and phase change material (PCM) is considered as a single module to achieve higher solar conversion efficiency. Such a system provides a high-energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. In the present study, a comprehensive model for CPV layers integrated with PCM was developed. This model was a coupled of a thermal model for CPV layers and fluid dynamic heat transfer model that took into account the phase-change phenomenon using enthalpy method, and the conversion of solar incident radiations. The effects of specific two variables on the solar cell temperature were investigated which were the PCM thickness of 50, 100, and 200 mm and concentration ratio (CR) from 5 to 20. It was found that the use of PCM could achieve a significant reduction of solar cell temperature. The solar cell temperature reduced from 180 °C to 38 °C by using PCM of thickness 200 mm at CR=5, while at the same PCM thickness, the cell temperature reduced from 510°C to 64°C at CR=20. Furthermore, the solar cell temperature was maintained at an average temperature of 38 °C for 8.4 hours using a 200 mm thickness of PCM at CR=5. In addition, at CR=20, the solar cell temperature was maintained at an average temperature of 64 °C for 2.0 hours using a 200 mm thickness of PCM. From the results, it was indicated that the use of PCM was an effective cooling technique since it attained a significant reduction in solar cell temperature, especially at high concentration ratio.

Comparison of Stratification in a Water Tank and a PCM-Water Tank

2007 ◽  
Author(s):  
A. Castell ◽  
C. Sole´ ◽  
M. Medrano ◽  
M. Nogue´s ◽  
L. F. Cabeza
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Temperature Change ◽  
High Energy ◽  
Hot Water ◽  
The Other ◽  
High Energy Density ◽  
Water Tank ◽  
Charging And Discharging Processes ◽  
Change Material

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.

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.

scholarly journals Theoretical Investigation of the Temperature Limits of an Actively Cooled High Concentration Photovoltaic System

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1902 ◽  
Author(s):  
Asmaa Ahmed ◽  
Katie Shanks ◽  
Senthilarasu Sundaram ◽  
Tapas Kumar Mallick
Keyword(s):  
Solar Cell ◽  
Concentration Ratio ◽  
Photovoltaic System ◽  
Thermal System ◽  
Outlet Temperature ◽  
Water Mixture ◽  
High Concentration ◽  
Cell Temperature ◽  
Photovoltaic Thermal System ◽  
Different Types

Concentrator photovoltaics have several advantages over flat plate systems. However, the increase in solar concentration usually leads to an increase in the solar cell temperature, which decreases the performance of the system. Therefore, in this paper, we investigate the performance and temperature limits of a high concentration photovoltaic Thermal system (HCPVT) based on a 1 cm2 multi-junction solar cell subjected to a concentration ratio from 500× to 2000× by using three different types of cooling fluids (water, ethylene glycol and water mixture (60:40), and syltherm oil 800). The results show that, for this configuration, the maximum volumetric temperature of the solar cell did not exceed the manufacturer’s recommended limit for the tested fluids. At 2000× the lowest solar cell temperature obtained by using water was 93.5 °C, while it reached as high as 109 °C by using syltherm oil 800, which is almost equal to the maximum operating limit provided by the manufacturer (110 °C). Overall, the best performance in terms of temperature distribution, thermal, and electrical efficiency was achieved by using water, while the highest outlet temperature was obtained by using syltherm oil 800.

Annual Performance Evaluation of Evacuated Tube Solar Air Collector With Phase Change Material

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Neeraj Mehla ◽  
Manoj Kumar ◽  
Avadhesh Yadav
Keyword(s):  
Performance Evaluation ◽  
Phase Change ◽  
Phase Change Material ◽  
Average Temperature ◽  
Hot Air ◽  
Solar Air Collector ◽  
Collector Efficiency ◽  
Evacuated Tube ◽  
Change Material

Abstract This manuscript has been presented to evaluate the annual performance of evacuated tube solar air collector (ETSAC) by using phase change material (PCM). The PCM (acetamide) simultaneously stores and exchange the heat to the air amid day hours. The heat stored by the PCM has been used to deliver hot air amid night hours. The performance of the system has been analyzed with a circular fin configuration along with reflectors at 0.035 kg/s air flowrate for 12 typical days. The performance of the system has been found excellent in the month of July. The maximum average temperature of PCM has been found to be as 87.8 °C and the maximum average collector efficiency as 31.4%.

Super-Cooling Suppression of Microencapsulated PCM

2014 ◽  
Vol 1070-1072 ◽  
pp. 422-426
Author(s):  
Shan Lv ◽  
Zhong Zhu Qiu
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Supply And Demand ◽  
High Energy ◽  
High Energy Density ◽  
Core Material ◽  
Microencapsulated Phase Change Material ◽  
State Changes ◽  
Main Barrier ◽  
Change Material

Microencapsulated Phase change material can absorb and release large amounts of latent heat over a defined temperature range as its physical state changes. The microencapsulated PCM has high energy density and isothermal behavior during charging and discharging and can avoid the contradiction of the energy supply and demand unbalance in time and space. Meanwhile, the shell can separate the phase change material from the outside environment in order to protect the core material. But the super-cooling problem is a main barrier for microencapsulated PCM application. So this paper talks about how to dealing with super-cooling based on related literatures and gives an overview about the methodology in this area.

scholarly journals Optimization of Phase-Change Material–Elastomer Composite and Integration in Kirigami-Inspired Voxel-Based Actuators

2021 ◽  
Vol 8 ◽  
Author(s):  
Gilles Decroly ◽  
Romain Raffoul ◽  
Clara Deslypere ◽  
Paul Leroy ◽  
Louis Van Hove ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Close Contact ◽  
Low Cost ◽  
High Energy ◽  
Design Approach ◽  
High Energy Density ◽  
Complex Tasks ◽  
Change Material ◽  
Actuation Strain

Phase-change material–elastomer composite (PCMEC) actuators are composed of a soft elastomer matrix embedding a phase-change fluid, typically ethanol, in microbubbles. When increasing the temperature, the phase change in each bubble induces a macroscopic expansion of the matrix. This class of actuators is promising for soft robotic applications because of their high energy density and actuation strain, and their low cost and easy manufacturing. However, several limitations must be addressed, such as the high actuation temperature and slow actuation speed. Moreover, the lack of a consistent design approach limits the possibility to build PCMEC-based soft robots able to achieve complex tasks. In this work, a new approach to manufacture PCMEC actuators with different fluid–elastomer combinations without altering the quality of the samples is proposed. The influence of the phase-change fluid and the elastomer on free elongation and bending is investigated. We demonstrate that choosing an appropriate fluid increases the actuation strain and speed, and decreases the actuation temperature compared with ethanol, allowing PCMECs to be used in close contact with the human body. Similarly, by using different elastomer materials, the actuator stiffness can be modified, and the experimental results showed that the curvature is roughly proportional to the inverse of Young’s modulus of the pure matrix. To demonstrate the potential of the optimized PCMECs, a kirigami-inspired voxel-based design approach is proposed. PCMEC cubes are molded and reinforced externally by paper. Cuts in the paper induce anisotropy into the structure. Elementary voxels deforming according to the basic kinematics (bending, torsion, elongation, compression and shear) are presented. The combination of these voxels into modular and reconfigurable structures could open new possibilities towards the design of flexible robots able to perform complex tasks.

Study on phase change material and its appropriate thickness for controlling solar cell module temperature

2018 ◽  
Vol 41 (1) ◽  
pp. 64-73 ◽  
Author(s):  
Vat Sun ◽  
Attakorn Asanakham ◽  
Thoranis Deethayat ◽  
Tanongkiat Kiatsiriroat
Keyword(s):  
Solar Cell ◽  
Phase Change ◽  
Phase Change Material ◽  
Change Material ◽  
Cell Module ◽  
Solar Cell Module

scholarly journals A Novel Approach on the Advancement in Polymer Phase Change Material in Solar Energy

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
G. Jegan ◽  
P. Ramani ◽  
T. J. Nagalakshmi ◽  
S. Chitra ◽  
T. Samraj Lawrence
Keyword(s):  
Solar Energy ◽  
Phase Change ◽  
Phase Change Material ◽  
High Energy ◽  
High Energy Density ◽  
Energy Output ◽  
Polymer Phase ◽  
Diverse Range ◽  
Novel Approach ◽  
Change Material

A wide interest has been shown in the application of solar energy in recent times. This motivated the researchers to make a development in the approach of solar energy, but there are different technologies like MPPT, CPG, and grid mode that have been used to maintain a constant temperature. Among these, phase change material has been used to regulate the temperature in the system. Solar energy is becoming an essential approach for increasing the efficiency of thermal energy conversion and utilizing polymeric step change composites, which have attracted extremely large interest in recent years due to their advantages of high energy density and powerful energy output stability. A plethora of reviews and reports have been published to compile the diverse range of PCMs made available for various applications. PCMs are created by improving thermophysical thermodynamic stability, latent heat, and heat capacity. Furthermore, the possible applications of polymer phase PCMs in a variety of fields, such as energy storage devices, thermal corrective action, and temperature-controlled drug carriers, are detailed. In this paper, a novel approach on the advancement of nanoconfined phase change material is defined along with the application of the solar energy system.

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