Effects of step height and particle diameter on the heat transfer and fluid flow of water-nanoencapsulated phase change material over the backward step

2019 ◽  
Vol 109 ◽  
pp. 104387 ◽  
Author(s):  
Masoud Kharati-Koopaee ◽  
Aref Ghaedi
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Phase Change ◽  
Phase Change Material ◽  
Particle Diameter ◽  
Step Height ◽  
Change Material

Fluid Flow and Heat Transfer Characteristics of Microencapsulated Phase Change Material Slurry in Turbulent Flow

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Hessam Taherian ◽  
Jorge L. Alvarado ◽  
Kalpana Tumuluri ◽  
Curt Thies ◽  
Chan-Hyun Park
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Fluid Flow ◽  
Turbulent Flow ◽  
Phase Change ◽  
Phase Change Material ◽  
Flow Conditions ◽  
Microencapsulated Phase Change Material ◽  
Change Material ◽  
Turbulent Flow Conditions

Microencapsulated phase change material (MPCM) slurry is consisted of a base fluid in which MPCM is dispersed. Due to apparent high heat capacity associated with phase change process, MPCM slurry can be used as a viable heat transfer fluid (HTF) for turbulent flow conditions. Heat transfer and fluid flow properties of the slurry in turbulent flow (3000 < Re < 6000) were determined experimentally. Dynamic viscosity of the MPCM slurry was measured at different temperatures close to the melting point of the material (20–30 °C). Pressure drop measurements under turbulent flow conditions were recorded for 6 MPCM samples at various concentrations. The pressure drop of the MPCM slurry was comparable to that of water despite the higher viscosity of the slurry. The effect of heat flux, MPCM mass concentration, flow rate and the type of phase change material was investigated. The effective heat capacity of slurry at the location where phase change occurs was found to be considerably higher than that of water. A nondimensional Nusselt number correlation was proposed in order to facilitate design of heat transfer loops with MPCM slurries as working fluid.

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.

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