Eexperimental Investigation of Heat Characteristics of Liquid Flow With Micro-Encapsulated Phase Change Material

2008 ◽  
Author(s):  
Rami Sabbah ◽  
Jamal Yagoobi ◽  
Said Al Hallaj
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Wall Temperature ◽  
Tube Wall ◽  
Operating Conditions ◽  
Working Fluid ◽  
Tube Wall Temperature ◽  
Encapsulated Phase Change Material ◽  
Change Material

This experimental study investigates the effect of presence of Micro-Encapsulated Phase Change Material (MEPCM) within the working fluid on thermal performances of the cooling system. To conduct this study, an experimental setup consisting of a steel tube with an inner diameter of 4.3mm, outer diameter of 6.3mm and a length of 1,016mm is selected. 5%, 10% and 20% mass concentration MEPCM slurries with particle diameter ranging between 5–15μm were included in this study. Tube wall temperature profile, fluid inlet, outlet temperatures, the pressure drop across the tube are measured and corresponding heat transfer coefficients are determined for various operating conditions. Differential Scanning Calometery (DSC) test results for an iterative method for local variables calculation. The experimental results showed significant enhancement in heat transfer coefficient higher than 50% and reduction in tube wall temperature higher than 35%. The controlling parameters are identified and their effects on the heat transfer characteristics are evaluated and analyzed.

Experimental and Numerical Investigation of Heat Transfer Characteristics of Liquid Flow With Micro-Encapsulated Phase Change Material

2008 ◽  
Author(s):  
Rami Sabbah ◽  
Jamal Yagoobi ◽  
Said Al Hallaj
Keyword(s):  
Heat Transfer ◽  
Numerical Model ◽  
Pressure Drop ◽  
Phase Change ◽  
Phase Change Material ◽  
Operating Conditions ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Encapsulated Phase Change Material ◽  
Change Material

This experimental and numerical study investigates Micro-Encapsulated Phase Change Material (MEPCM) heat transfer characteristics and corresponding pressure drop. To conduct this study, an experimental setup consisting of a steel tube with an inner diameter of 4.3mm, outer diameter of 6.5mm and a length of 1,016mm is selected. A MEPCM mass concentration of 20% slurry with particle diameter ranging between 5–15μm is included in this study. Tube wall temperature profile, fluid inlet, outlet temperatures, the pressure drop across the tube are measured and corresponding Nusselt number are determined for various operating conditions. The experimental results are used to validate the numerical model predictions. The numerical model results show good agreement with the experimental data under various operating conditions. The controlling parameters are identified and their effects on the heat transfer characteristics of micro-channels with MEPCM slurries are evaluated.

Heat Transfer Characteristics of Liquid Flow With Micro-Encapsulated Phase Change Material: Numerical Study

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
R. Sabbah ◽  
J. Seyed-Yagoobi ◽  
S. Al-Hallaj
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Liquid Flow ◽  
Tube Length ◽  
Working Fluid ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Encapsulated Phase Change Material ◽  
Change Material

This numerical investigation fundamentally explores the thermal boundary layers’ characteristics of liquid flow with micro-encapsulated phase change material (MEPCM). Unlike pure liquids, the heat transfer characteristics of MEPCM slurry cannot be simply presented in terms of corresponding dimensionless controlling parameters, such as Peclet number. In the presence of phase change particles, the controlling parameters’ values change significantly along the tube length due to the phase change. The MEPCM slurry flow does not reach a fully developed condition as long as the MEPCM particles experience phase change. The presence of MEPCM in the working fluid slows the growth of the thermal boundary layer and extends the thermal entry length. The local heat transfer coefficient strongly depends on the corresponding location of the melting zone interface. The heat transfer characteristics of liquid flow with MEPCM are presented as well.

Natural Convection With Micro-Encapsulated Phase Change Material

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
R. Sabbah ◽  
J. Seyed-Yagoobi ◽  
S. Al-Hallaj
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Phase Change ◽  
Phase Change Material ◽  
Operating Conditions ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Vertical Walls ◽  
Encapsulated Phase Change Material ◽  
Change Material

This study numerically explores the effect of presence of micro-encapsulated phase change material (MEPCM) on the heat transfer characteristics of a fluid in a rectangular cavity driven by natural convection. The natural convection is generated by the temperature difference between two vertical walls at constant temperatures. The phase change material (PCM) melts in the vicinity of the hot wall and solidifies near the cold wall. Unlike the pure fluids, the heat transfer characteristics of MEPCM slurry cannot be simply presented in terms of corresponding dimensionless controlling parameters such as Rayleigh number. In the presence of phase change particles, the controlling parameters’ values change significantly due to the local phase change. The numerical results show significant increase in the heat transfer coefficient (up to 80%) at the considered operating conditions. This increase is a result of the MEPCM latent heat and the increased volumetric thermal expansion coefficient due to MEPCM volume change during melting.

Heat Transfer Characteristics of Liquid Flow With Micro-Encapsulated Phase Change Material: Experimental Study

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
R. Sabbah ◽  
J. Seyed-Yagoobi ◽  
S. Al-Hallaj
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Transfer Coefficient ◽  
Liquid Flow ◽  
Wall Temperature ◽  
Tube Wall ◽  
Heat Transfer Characteristics ◽  
Tube Wall Temperature ◽  
Encapsulated Phase Change Material ◽  
Change Material

This experimental study investigates the heat transfer characteristics of a liquid flow with micro-encapsulated phase change material (MEPCM). The MEPCM mass concentration is varied between 0 and 20 percent with average particle diameter of 10 μm. Tube wall temperature profile, fluid inlet and outlet temperatures are measured and the corresponding heat transfer coefficient is determined for various operating conditions. A wide range of the controlling parameters, MEPCM concentration, heat flux, inlet temperature, and flow rate are covered. The results showed significant enhancements in heat transfer coefficient (higher than 50%) and reduction in tube wall temperature (higher than 40%). The results also showed that the heat transfer enhancement curve showed resemblance to the MEPCM specific heat curve.

Numerical Investigation of Flow and Heat Transfer Performance of Nano-Encapsulated Phase Change Material Slurry in Microchannels

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Sarada Kuravi ◽  
Krishna M. Kota ◽  
Jianhua Du ◽  
Louis C. Chow
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Numerical Investigation ◽  
Phase Change Material ◽  
Temperature Fields ◽  
Heat Transfer Fluid ◽  
Inlet Temperature ◽  
Bulk Fluid ◽  
Encapsulated Phase Change Material ◽  
Change Material

Microchannels are used in applications where large amount of heat is produced. Phase change material (PCM) slurries can be used as a heat transfer fluid in microchannels as they provide increased heat capacity during the melting of phase change material. For the present numerical investigation, performance of a nano-encapsulated phase change material slurry in a manifold microchannel heat sink was analyzed. The slurry was modeled as a bulk fluid with varying specific heat. The temperature field inside the channel wall is solved three dimensionally and is coupled with the three dimensional velocity and temperature fields of the fluid. The model includes the microchannel fin or wall effect, axial conduction along the length of the channel, developing flow of the fluid and not all these features were included in previous numerical investigations. Influence of parameters such as particle concentration, inlet temperature, melting range of the PCM, and heat flux is investigated, and the results are compared with the pure single phase fluid.

Characteristics of Hydro-Dynamically and Thermally Developing Liquid Flow With Micro-Encapsulated Phase Change Material

2009 ◽  
Author(s):  
Rami Sabbah ◽  
Jamal Yagoobi ◽  
Said Al Hallaj
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Phase Change ◽  
Phase Change Material ◽  
Boundary Layers ◽  
Liquid Flow ◽  
Thermal Boundary Layer ◽  
Encapsulated Phase Change Material ◽  
Change Material ◽  
Thermal Boundary Layers

This numerical investigation explores the hydrodynamic and thermal boundary layers characteristics of a liquid flow with Micro-Encapsulated Phase Change Material (MEPCM). Unlike pure liquids, the heat transfer characteristics of MEPCM slurry can not be simply presented in terms of corresponding dimensionless controlling parameters such as Peclet number. In the presence of phase change particles, the controlling parameters’ values change significantly along the tube length due to the phase change. As a result, the hydrodynamic and thermal boundary layers are significantly affected by the changing parameters. The numerical results reveal that the growth of the thermal boundary layer for MEPCM slurries is different than for pure liquids. The presence of MEPCM in the working fluid slows the growth of the thermal boundary layer and extends the thermal entry length. The local heat transfer coefficient strongly depends on the location of the melting zone interface.

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