Voiding Effects on the Thermal Response of Metallic Phase Change Materials Under Pulsed Power Loading

2017 ◽  
Author(s):  
David Gonzalez-Nino ◽  
Lauren M. Boteler ◽  
Nicholas R. Jankowski ◽  
Dimeji Ibitayo ◽  
Pedro O. Quintero
Keyword(s):  
Silicon Nitride ◽  
Heat Source ◽  
Phase Change ◽  
Phase Change Materials ◽  
Cooling System ◽  
Thermal Response ◽  
Metallic Phase ◽  
Maximum Temperature ◽  
Before And After ◽  
Power Loading

Metallic phase change materials (PCMs) have been demonstrated as an excellent alternative to act as a passive cooling system for pulse power applications. The possibility of integrating metallic PCMs, directly on top of a heat source, reducing the thermal resistance between the device and the cooling solution, could result in a significant improvement in thermal management for transient applications. However, the effectiveness of this method of implementation will depend on the quality of the interface between the metallic PCM and the heat source. For this work, a metallic PCM (49Bi/18Pb/12Sn/21In-Bi/Pb/Sn/In for simplicity) was placed directly on top of a device that has a layer of silicon nitride on the top. The device was pulsed with powers of 40W – 160W (84W/cm2 – 338W/cm2) with a 20 ms duration. After reaching the maximum power, the device was pulsed for a second cycle, and the temperature profiles were compared. Micrographical inspections, at the interlayer between the silicon nitride and metallic PCM, were performed before and after the pulses and compared. A maximum temperature of ≈20–25% higher was observed in the performance (at 80W) after pulse cycling. A visual inspection at the mating surfaces, between the metallic PCM and device, showed a clear difference between the contact surfaces before and after pulses. Significant voiding at the PCM interfacial layer was observed after cyclic loading which is believed to be the cause of the recorded increment in maximum temperature.

Analysis of the Applicability of Effective Thermophysical Properties to Composite Phase Change Materials

2021 ◽  
Vol 1016 ◽  
pp. 813-818
Author(s):  
Zi Wei Li ◽  
Elisabetta Gariboldi
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Materials ◽  
Effective Properties ◽  
Average Energy ◽  
Thermal Response ◽  
Metallic Phase ◽  
Stable Phase ◽  
Bottom Surface ◽  
Temperature Model

Coarse form-stable phase change materials (FS-PCMs) can tailor the properties of pure PCMs. This is often attained by the presence of high-melting, high-thermal conductivity metallic phase which enhances the thermal energy storage/release. The evaluation of the thermal response of these composite materials in unsteady conditions, is not an easy task, and simplifications introduced to deal with them must be carefully considered. A set of FS-PCMs of prismatic geometry with polymeric wax as PCM and an Al foam with various pore sizes, modelled as BCC lattice has been considered in this paper. The thermal response under a set of boundary conditions with constant heat flux at the bottom surface, all other being adiabatic, was investigated both by direct simulations approach modelling the two phases and the ‘1-temperature model’, which considers the material as homogeneous and characterized by a proper set of effective properties. The ‘1-temperature model’ is able to closely reproduce the whole the local thermal history only within certain validity ranges, even if it can well reproduce the ‘average’ energy storage due to the transformation of the PCM phase.

Numerical Evaluation of Multiple Phase Change Materials for Pulsed Electronics Applications

2016 ◽  
Author(s):  
David Gonzalez-Nino ◽  
Lauren M. Boteler ◽  
Dimeji Ibitayo ◽  
Nicholas R. Jankowski ◽  
Pedro O. Quintero
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Source ◽  
Phase Change ◽  
Phase Change Materials ◽  
High Energy ◽  
Heat Of Fusion ◽  
Maximum Temperature ◽  
Conductivity Enhancement ◽  
Fast Transient

A simple and easy to implement 1-D heat transfer modeling approach is presented in order to investigate the performance of various phase change materials (PCMs) under fast transient thermal loads. Three metallic (gallium, indium, and Bi/Pb/Sn/In alloy) and two organic (erythritol and n-octadecane) PCMs were used for comparison. A finite-difference method was used to model the transient heat transfer through the system while a heat integration or post-iterative method was used to model the phase change. To improve accuracy, the material properties were adjusted at each iteration depending on the state of matter of the PCM. The model assumed that the PCM was in direct contact with the heat source, located on the top of the chip, without the presence of a thermal conductivity enhancement. Results show that the three metallic PCMs outperform organic PCMs during fast transient pulses in spite of the fact that two of the metallic PCMs (i.e. indium and Bi/Pb/Sn/In) have considerably lower volumetric heats of fusion than erythritol. This is due to the significantly higher thermal conductivity values of metals which allow faster absorption of the heat energy by the PCM, a critical need in high-energy short pulses. The most outstanding case studied in this paper, Bi/Pb/Sn/In having only 52% of erythritol’s heat of fusion, showed a maximum temperature 20°C lower than erythritol during a 32 J and 0.02 second pulse. This study has shown thermal buffering benefits by using a metallic PCM directly in contact with the heat source during short transient heat loads.

Metallic Phase Change Material's Microstructural Stability Under Repetitive Melting/Solidification Cycles

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Rafael Báez ◽  
Luis E. González ◽  
Manny X. de Jesús-López ◽  
Pedro O. Quintero ◽  
Lauren M. Boteler
Keyword(s):  
Phase Change ◽  
Thermal Management ◽  
Thermal Loading ◽  
Phase Change Materials ◽  
Cooling System ◽  
Physical Stability ◽  
Metallic Phase ◽  
Heat Of Fusion ◽  
Microstructural Stability ◽  
Wide Range

Abstract Metallic phase change materials (mPCMs) have been demonstrated as potential passive cooling solution for pulse power applications. The possibility of integrating a metallic PCM directly on top of a heat source, reducing the thermal resistance between the device and the cooling system, could result in a significant improvement in thermal management for transient applications. However, many thermo-physical properties of these alloys are still unknown; furthermore, their microstructural stability with repetitive melting/solidification cycles is not warrant. In this work, we provide a series of potential mPCMs for thermal management of electronics operating on a wide range of application temperatures, followed by an experimental investigation of microstructural and thermo-physical stability of these materials under repetitive melting solidification cycles. The results of the effect of cyclic thermal loading of theses alloys on the melting behavior and latent heat of fusion are discussed. Thermal stability of 51.0 wt  % In–32.5 wt %Bi–16.5 wt %Sn and 50 wt %Bi–26.7 wt %Pb–13.3 wt %Sn–10 wt %Cd alloys, as potential midtemperature mPCM, has been evaluated. The results suggest that these mPCMs maintain their thermo-physical stability over large periods of thermal cycles.

Numerical Thermal Performance Investigation of an Electric Motor Passive Cooling System Employing Phase Change Materials

2021 ◽  
Author(s):  
Ali Deriszadeh ◽  
Filippo de Monte ◽  
Marco Villani
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Electric Motor ◽  
Phase Change Materials ◽  
Cooling System ◽  
Passive Cooling ◽  
Time Step ◽  
Cooling Performance ◽  
Passive Cooling System ◽  
Change Material

Abstract This study investigates the cooling performance of a passive cooling system for electric motor cooling applications. The metal-based phase change materials are used for cooling the motor and preventing its temperature rise. As compared to oil-based phase change materials, these materials have a higher melting point and thermal conductivity. The flow field and transient heat conduction are simulated using the finite volume method. The accuracy of numerical values obtained from the simulation of the phase change materials is validated. The sensitivity of the numerical results to the number of computational elements and time step value is assessed. The main goal of adopting the phase change material based passive cooling system is to maintain the operational motor temperature in the allowed range for applications with high and repetitive peak power demands such as electric vehicles by using phase change materials in cooling channels twisted around the motor. Moreover, this study investigates the effect of the phase change material container arrangement on the cooling performance of the under study cooling system.

Application of Phase Change Materials to Thermal Control of Electronic Modules: A Computational Study

1997 ◽  
Vol 119 (1) ◽  
pp. 40-50 ◽  
Author(s):  
D. Pal ◽  
Y. K. Joshi
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Cooling System ◽  
Computational Study ◽  
Power Level ◽  
Thermal Control ◽  
The Other ◽  
Three Dimensions ◽  
Temperature Isotherm ◽  
Laminate Thickness

A computational model is developed to predict the performance of phase change materials(PCMs) for passive thermal control of electronic modules during transient power variations or following an active cooling system failure. Two different ways of incorporating PCM in the module are considered. One is to place a laminate of PCM outside the multichip module, and the other is to place the PCM laminate between the substrate and the cold plate. Two different types of PCMs are considered. One is n-Eicosene, which is an organic paraffin, and the other one is a eutectic alloy of Bi/Pb/Sn/In. Computations are performed in three dimensions using a finite volume method. A single domain fixed grid enthalpy porosity method is used to model the effects of phase change. Effects of natural convection on the performance of PCM are also examined. Results are presented in the form of time-wise variations of maximum module temperature, isotherm contours, velocity vectors, and melt front locations. Effects of PCM laminate thickness and power levels are studied to assess the amount of PCM required for a particular power level. The results show that the PCMs are an effective option for passive cooling of high density electronic modules for transient periods.

Magnetic Transition of Metallic Phase‐Change Materials

2020 ◽  
pp. 2000425
Author(s):  
Chao He ◽  
Chong Qiao ◽  
Zhe Yang ◽  
Weiming Cheng ◽  
Hao Tong ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Magnetic Transition ◽  
Metallic Phase

scholarly journals C/C‐SiC component for metallic phase change materials

2020 ◽  
Vol 17 (5) ◽  
pp. 2040-2050 ◽  
Author(s):  
Veronika Stahl ◽  
Yuan Shi ◽  
Werner Kraft ◽  
Tim Lanz ◽  
Peter Vetter ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Metallic Phase

Air-cooling system based on phase change materials for a vehicle cabin

2020 ◽  
Author(s):  
Sangeetha Krishnamoorthi ◽  
L. Prabhu ◽  
Glen Kuriakose ◽  
Dave Jose lewis ◽  
J. Harikrishnan
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Cooling System ◽  
Air Cooling ◽  
Vehicle Cabin ◽  
Air Cooling System
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