Phase Change Material Particles and Their Application in Heat Transfer Fluids

2014 ◽  
pp. 457-488
Author(s):  
J. J. Xu ◽  
F. Y. Cao ◽  
B. Yang
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Heat Transfer Fluids ◽  
Change Material

scholarly journals Application of Phase Change Material in Sustainable Cooling of Data Centers

2013 ◽  
Author(s):  
Nikhil Dhiman ◽  
Jeet Shah ◽  
Dereje Agonafer ◽  
Naveen Kannan ◽  
James Hoverson ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Hot Water ◽  
Shear Stresses ◽  
Heat Transfer Fluids ◽  
Data Center Cooling ◽  
Heat Transfer Phenomenon ◽  
Pipe Joints ◽  
Change Material

The ever increasing information technology heat load and data center cooling energy are the main reasons to investigate the performance of microencapsulated phase change slurry over other heat transfer fluids. Microencapsulated phase change slurry is dispersion where the phase change material, microencapsulated by a polymeric capsule, is dispersed in water. Compared to water, these new fluids have a higher heat capacity during phase change and a possible enhancement, as a result of this phase change, in the heat transfer phenomenon. The composition of phase change material used in slurry greatly affects its efficiency, If not selected properly it can cause serious damage, e.g. agglomeration and clogging of pipes. The main objective of this work is to develop standalone pumpable microencapsulated phase change slurry that is able to withstand shear stresses of the pump and other course surfaces of pipe and pipe joints. In this study, experiments were performed, to determine performance of microencapsulated phase change slurry over conventional heat transfer fluids. After certain pumping cycles, scanning electron microscopy (SEM) has been done to analyze the conditions of shell material of polymeric capsule. Results obtained from SEM show that centrifugal pump is compatible with mPCM particle size upto 3 μm. It is true that selected mPCS have shown better performance over water in hot water bath in case of thermal storage. Also, closed loop final testing has shown that heat flux is about 2–3 times higher with mPCS than water.

Thermal Analysis of Encapsulated Phase Change Materials for Energy Storage

2011 ◽  
Author(s):  
Weihuan Zhao ◽  
Alparslan Oztekin ◽  
Sudhakar Neti ◽  
Kemal Tuzla ◽  
Wojciech M. Misiolek ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Phase Change Materials ◽  
Solar Power ◽  
Solar Thermal Energy ◽  
Heat Transfer Fluids ◽  
Change Material

Concentrating solar power technology is recognized as an attractive option for solar power. A major limitation however is that solar power is available for only about 2,000 hours a year in many places. Therefore it is critical to find ways to store solar thermal energy for the off hours and it is better to store the energy at high temperatures. The present work deals with certain aspects of storing solar thermal energy at high temperatures with phase change materials (PCM) in the range of 275°C to 425°C. NaNO3 is selected as a phase change material encapsulated by stainless steel. The objective is the storage of hundreds mega-watt-hours equivalent of solar energy in systems using encapsulated phase change materials (EPCM). Numerical predictions of conduction and phase change processes are reported here in the form of transient temperature profiles in the PCM and encapsulation materials of EPCM capsules for convective boundary conditions outside EPCM. The time for heating and melting during charging (storage of thermal energy into encapsulated phase change material) and the time for cooling and solidification during discharging (discharge/retrieval of thermal energy) are predicted for NaNO3 PCM in encapsulation. For a temperature range of about 125°C around melting/freezing temperature of the PCM the time it takes to melt/freeze the PCM during storage/retrieval is much longer than the time it takes for diffusion (sensible heat) storage alone. Depending on the properties of the PCM, the energy associated with the latent heat of melting can be a significant leading to smaller thermal energy storage systems and lower costs. As can be expected, the time for heat transfer is much shorter for liquid heat transfer fluids compared to those for gaseous heat transfer fluids that transport the energy to the EPCM.

scholarly journals A numerical model and validation of phase change material integrated thermoelectric radiant cooling panel

2019 ◽  
Vol 111 ◽  
pp. 01001
Author(s):  
Hansol Lim ◽  
Hye-Jin Cho ◽  
Seong-Yong Cheon ◽  
Soo-Jin Lee ◽  
Jae-Weon Jeong
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Numerical Model ◽  
Surface Temperature ◽  
Phase Change ◽  
Transfer Coefficient ◽  
Phase Change Material ◽  
Overall Heat Transfer Coefficient ◽  
Radiant Cooling ◽  
Change Material

A phase change material based radiant cooling panel with thermoelectric module (PCM-TERCP) is proposed in this study. It consists of two aluminium panels, and phase change materials (PCMs) sandwiched between the two panels. Thermoelectric modules (TEMs) are attached to one of the aluminium panels, and heat sinks are attached to the top side of TEMs. PCM-TERCP is a thermal energy storage concept equipment, in which TEMs freeze the PCM during the night whose melting temperature is 16○C. Therefore, the radiant cooling panel can maintain a surface temperature of 16◦C without the operation of TEM during the day. Furthermore, it is necessary to design the PCM-TERCP in a way that it can maintain the panel surface temperature during the targeted operating time. Therefore, the numerical model was developed using finite difference method to evaluate the thermal behaviour of PCM-TERCP. Experiments were also conducted to validate the performance of the developed model. Using the developed model, the possible operation time was investigated to determine the overall heat transfer coefficient required between radiant cooling panel and TEM. Consequently, the results showed that a overall heat transfer coefficient of 394 W/m2K is required to maintain the surface temperature between 16○C to 18○C for a 3 hours operation.

Experimental Study on Thermal Characteristics of Finned Coil LHSU Using Paraffin as Phase Change Material

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Guansheng Chen ◽  
Nanshuo Li ◽  
Huanhuan Xiang ◽  
Fan Li
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Phase Change ◽  
Phase Change Material ◽  
Water Flow ◽  
Water Flow Rate ◽  
Thermal Characteristics ◽  
Heat Transfer Fluid ◽  
Latent Heat Storage ◽  
Change Material

It is well known that attaching fins on the tubes surfaces can enhance the heat transfer into and out from the phase change materials (PCMs). This paper presents the results of an experimental study on the thermal characteristics of finned coil latent heat storage unit (LHSU) using paraffin as the phase change material (PCM). The paraffin LHSU is a rectangular cube consists of continuous horizontal multibended tubes attached vertical fins at the pitches of 2.5, 5.0, and 7.5 mm that creates the heat transfer surface. The shell side along with the space around the tubes and fins is filled with the material RT54 allocated to store energy of water, which flows inside the tubes as heat transfer fluid (HTF). The measurement is carried out under four different water flow rates: 1.01, 1.30, 1.50, and 1.70 L/min in the charging and discharging process, respectively. The temperature of paraffin and water, charging and discharging wattage, and heat transfer coefficient are plotted in relation to the working time and water flow rate.

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 Transient Analysis of Heat Transfer Across the Residential Building Roof with Pcm and Wood Wool- A Case Study by Numerical Simulation Approach

2013 ◽  
Vol 59 (4) ◽  
pp. 483-497 ◽  
Author(s):  
D. Prakash ◽  
P. Ravikumar
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Phase Change ◽  
Phase Change Material ◽  
Transient Analysis ◽  
Residential Building ◽  
Building Roof ◽  
Type 3 ◽  
Change Material

Abstract In this paper, transient analysis on heat transfer across the residential building roof having various materials like wood wool, phase change material and weathering tile is performed by numerical simulation technique. 2-dimensional roof model is created, checked for grid independency and validated with the experimental results. Three different roof structures are included in this study namely roof with (i). Concrete and weathering tile, (ii). Concrete, phase change material and weathering tile and (iii). Concrete, phase change material, wood wool and weathering tile. Roof type 3 restricts 13% of heat entering the room in comparison with roof having only concrete and weathering tile. Also the effect of various roof layers’ thickness in the roof type 3 is investigated and identified that the wood wool plays the major role in arresting the entry of heat in to the room. The average reduction of heat is about 10 % for an increase of a unit thickness of wood wool layer.

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