scholarly journals The Effect of Arachidic Acid Mixtures on the Cooling Performance of a Heat Sink

2021 ◽  
Vol 11 (19) ◽  
pp. 9201
Author(s):  
Mohammad Hammoud ◽  
Ibrahim Mjallal ◽  
Hussien Farhat ◽  
Nour Abdallah ◽  
Charbel Habchi ◽  
...  
Keyword(s):  
Latent Heat ◽  
Heat Sink ◽  
Phase Change Materials ◽  
Heat Dissipation ◽  
Electronic Device ◽  
Arachidic Acid ◽  
Heat Of Fusion ◽  
Potassium Oleate ◽  
Sodium Decanoate ◽  
High Latent Heat

The temperature of an electronic device is one of the most important parameters to deal with. Any increase above the temperature limits results in a failure in the device. Thus, to ensure good operation, an electronic device should be cooled. One promising technique is the use of Phase Change Materials (PCMs) for their well-known ability to absorb the heat dissipated by the device, thanks to their high latent heat of fusion. Arachidic acid is a fatty acid that, when mixed with sodium decanoate and potassium oleate salts, can be used as a promising PCM due to its high latent heat. This paper aims to shed light on the use such mixtures of Arachidic acid for cooling in a heat sink. An experimental setup was built for this purpose. The results show that the Arachidic acid mixtures are suitable for applications requiring intermediate heat dissipation.

Metallic Composites Phase-Change Materials for High-Temperature Thermal Energy Storage

2013 ◽  
Author(s):  
Xiaobo Li ◽  
Hengzhi Wang ◽  
Hui Wang ◽  
Sohae Kim ◽  
Keivan Esfarjani ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Metallic Alloys ◽  
Heat Of Fusion ◽  
Latent Heat Of Fusion ◽  
High Latent Heat

Inorganic materials and organic salts are usually used as phase change materials (PCMs) for thermal energy storage. Some of these materials have high latent heat of fusion; however one major drawback of these materials is the low thermal conductivity, which limits the rate of charging and discharging process. In this paper, we studied metallic alloys (eutectic alloys or alloys with a narrow melting temperature range) as phase-change materials, which have both high thermal conductivity and high latent heat of fusion. A formula was presented from entropy change to predict the latent heat of fusion of metallic alloys. We found that the latent heat of fusion of alloys can be expressed from three different contributions: the latent heat from each element, the sensible heat, and the mixing entropy. From the theory we also showed that latent heat of fusion could be greatly increased by maximizing the entropy of mixing, which can be realized by introduce more elements in the alloys, i.e., form ternary alloys by adding elements to binary alloys. This idea is demonstrated by the synthesis and measurement of the binary alloy 87.8Al-12.2Si (at%) and ternary alloy 45Al-40Si-15Fe (at%). The metallic alloy is synthesized by hot pressing method. The latent heat of fusion of 45Al-40Si-15Fe (at%) is about 865 kJ/kg with melting temperature from 830 °C to 890 °C from the differential scanning calorimetry (DSC) measurement, comparing with 554.9 kJ/kg and 578.3 °C for the binary alloy 87.8Al-12.2Si (at%). From the binary to the ternary alloy, the contribution to the latent heat from mixing entropy increases by 17%.

Paraffin wax microsphere embedded epoxy composites for potential thermal management in electronic devices

2018 ◽  
Vol 31 (7) ◽  
pp. 767-777
Author(s):  
Gopal Krishna Singh Khagokpam ◽  
Sudipta Halder
Keyword(s):  
Thermal Management ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Epoxy Composite ◽  
Hot Spot ◽  
Electronic Devices ◽  
Average Diameter ◽  
Paraffin Wax ◽  
Heat Of Fusion ◽  
Epoxy Network

Miniaturization of electronic devices with more computing power has created a challenging set of aspects in thermal management. Present work is based on phase change materials microsphere and its incorporation in the epoxy network to develop a new class of potting material facilitating thermal management for miniaturized electronic devices. A facile and scalable method was implemented to synthesize paraffin wax microspheres (PMPs). It was dispersed into a room temperature curing epoxy network to fabricate the epoxy composite with high latent heat of fusion and high thermal stability. PMPs obtained have spherical morphology with an average diameter of approximately 5 µm. The PMP/epoxy composite can store 34.34 and 49.3 J g−1 of latent heat energy at 30 and 40 wt% PMP loading, respectively. Leakage test reveals that leaching declined as the size of PMP is reduced. Incorporation of PMP into the epoxy network reduces the compressive strength, but still resilient enough to protect electronic devices. This is an added advantage over the potential to mitigate the issue of hot spot in electronic devices as demonstrated by infrared thermography. The application of such composite is not limited only as electronic potting materials but also has the potential for other thermal energy storage applications.

High latent heat and recyclable form-stable phase change materials prepared via a facile self-template method

2020 ◽  
Vol 396 ◽  
pp. 125265 ◽  
Author(s):  
Yunzhi Tan ◽  
Yu Xiao ◽  
Rui Chen ◽  
Changlin Zhou ◽  
Lei Wang ◽  
...  
Keyword(s):  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Template Method ◽  
Stable Phase ◽  
High Latent Heat

Latent Heat of Fusion and Melting Temperature of Molten Salt Based Carbon Nanotube Suspensions Used as Phase Change Materials

2015 ◽  
Author(s):  
Pau Gimenez-Gavarrell ◽  
Vincent D. Romanin ◽  
Sonia Fereres
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Melting Temperature ◽  
Latent Heat ◽  
Base Fluid ◽  
Phase Change Materials ◽  
Heat Of Fusion ◽  
Latent Heat Of Fusion ◽  
Base Materials ◽  
Nanoparticle Suspensions

Thermal Energy Storage (TES) can improve the efficient and economical use of available resources associated with renewable energies. The choice of Phase Change Materials (PCM) for TES applications is particularly attractive, since PCMs provide high energy storage densities, low costs, and allow energy storage at constant temperatures during the melting/solidification process. However, most commonly used PCMs have low thermal conductivity values, typically less than 1 W/mK. This leads to insufficient heat exchange rates in many applications, where power is as important as the amount of energy stored. Previous studies have shown that adding nanoparticles to molten salts can enhance the thermal conductivity and heat capacity, thus improving performance in TES systems. This study analyzes how adding nanoparticles to ionic liquids/solids affects the latent heat of fusion and melting temperature, critical characteristics of many thermal management systems. An important aspect of nanoparticle suspension preparation is the synthesis method, both from the point of view of scalability and effect on thermophysical properties. Several nanoparticle suspensions are synthesized with carbon nanotubes (CNT) and salt or ionic liquid base materials, using different synthesis methods and sonication times. The melting point and latent heat of fusion are measured for the base materials and nanoparticle suspensions using a Differential Scanning Calorimeter (DSC). The change in latent heat and melting temperature of the nanofluid with respect to the base fluid is shown to be present but not substantial. Possible explanations for the modification of thermal properties with respect to the base fluid are discussed.

scholarly journals Development of Binary Eutectic Organic Phase Change Materials for Solar Thermal Energy Storage Systems

2019 ◽  
Vol 9 (2) ◽  
pp. 2207-2210
Keyword(s):  
Energy Storage ◽  
Melting Point ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Thermal ◽  
Heat Of Fusion ◽  
Solar Thermal Energy ◽  
Latent Heat Of Fusion ◽  
High Latent Heat

Solar thermal energy storage unit anchored fatty acids as Phase Change Materials (PCMs) having narrow range of transition temperature and high latent heat of fusion. In this paper, a new novel eutectic PCM was developed by using a fatty acid (acetamide) and non-paraffin organic PCM (acetanilide) for a sharp melting point and high latent heat of fusion. The optimized eutectic PCM may be used for middle temperature range solar thermal energy storage systems. The binary mixture of acetamide and acetanilide at various compositions by mass ratio (wt%) was prepared and optimized experimentally for lowest value of melting point at a eutectic mixture composition of 60 wt% of acetamide and 40 wt% of acetanilide. Eutectic PCM was analyzed by Differential Scanning Calorimetry (DSC) and Field-Emission Scanning Electron Microscopy (FE-SEM). DSC results revealed that optimized eutectic PCM has a sharp melting point of 65.37°C and high latent heat of fusion of 224.67 kJ/kg. Accelerated thermal cycle testing of optimized eutectic PCM was performed for 100 melting and freezing cycles and change in melting temperature and latent heat of fusion was acceptable.

scholarly journals Investigation of Thermal Properties of Novel Phase Change Material Mixtures (Octadecane-Diamond) with Laser Flash Analysis

2019 ◽  
Vol 26 (4) ◽  
pp. 211-218
Author(s):  
Mateusz Sierakowski ◽  
Wojciech Godlewski ◽  
Roman Domański ◽  
Jakub Kapuściński ◽  
Tomasz Wiśniewski ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Phase Change ◽  
Power Plants ◽  
Large Scale ◽  
Phase Change Materials ◽  
Heat Dissipation ◽  
Electronics Cooling ◽  
Diamond Powder ◽  
Heat Of Fusion

AbstractPhase change materials (PCMs) are widely used in numerous engineering fields because of their good heat storage properties and high latent heat of fusion. However, a big group of them has low thermal conductivity and diffusivity, which poses a problem when it comes to effective and relatively fast heat transfer and accumulation. Therefore, their use is limited to systems that do not need to be heated or cooled rapidly. That is why they are used as thermal energy storage systems in both large scale in power plants and smaller scale in residential facilities. Although, if PCMs are meant to play an important role in electronics cooling, heat dissipation, or temperature stabilization in places where the access to cooling water is limited, such as electric automotive industry or hybrid aviation, a number of modifications and improvements needs to be introduced. Investigation whether additional materials of better thermal properties will affect the thermal properties of PCM is therefore of a big interest. An example of such material is diamond powder, which is a popular additive used in abradants. Its thermal diffusivity and conductivity is significantly higher than for a pure PCM. The article presents the results of an analysis of the effect of diamond powder on thermal conductivity and diffusivity of phase change materials in the case of octadecane.

scholarly journals Development of a Novel Multi-Channel Thermocouple Array Sensor for In-Situ Monitoring of Ice Accretion

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2165
Author(s):  
Luke Rieman ◽  
Erdogan Guk ◽  
Taeseong Kim ◽  
Chankyu Son ◽  
Jung-Sik Kim
Keyword(s):  
Latent Heat ◽  
In Situ Monitoring ◽  
Heat Of Fusion ◽  
Ice Accretion ◽  
Latent Heat Of Fusion ◽  
Array Architecture ◽  
Thermocouple Temperature ◽  
In Situ Detection ◽  
High Latent Heat

A test was performed to determine the efficacy of a novel multi-channel thermocouple temperature sensor employing “N+1” array architecture for the in-situ detection of icing in cold climates. T-type thermoelements were used to fabricate a sensor with six independent temperature sensing points, capable of two-dimensional temperature mapping. The sensor was intended to detect the high latent heat of fusion of water (334 J/g) which is released to the environment during ice formation. The sensor was embedded on a plywood board and an aluminium plate, respectively by an epoxy resin. Three different ice accretion cases were considered. Ice accretion for all cases was achieved on the surface of the resin layer. In order to analyse the temperature variation for all three cases, the first 20 s response for each case was averaged between three cases. A temperature increase of (1.0 ± 0.1) °C and (0.9 ± 0.1) °C was detected by the sensors 20 s after the onset of icing, attributed to the latent heat of fusion of water. The results indicate that the sensor design is well-suited to cold temperature applications and that detection of the latent heat of fusion could provide a rapid and robust means of icing detection.

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