Thermal Performance of a Phase Change Material-Based Heat Sink Subject to Constant and Power Surge Heat Loads: A Numerical Study

Author(s):  
Rajesh Akula ◽  
C. Balaji

Abstract A power surge is a frequent phenomenon that occurs in electronics. Inadequate and improper cooling during power surges results in a rapid increase in operating temperatures that may lead to failure of the electronics. In the present investigation, the thermal characteristics of a phase change material (PCM)-based heat sinks, having different configurations and orientations of fins, subject to (i) constant heat load and (ii) heat load with a power surge, are studied numerically. Preliminary investigations showed that a heat sink with PCM gets heated at a much lower temperature than an air cooled heat sink. Following this, four finned heat sinks are considered for further investigations. The heat sink with PCM, sans fins, is used for baseline comparison. The orientation of fins in the other four heat sinks is either vertical or horizontal with square and rectangular cross sections. The heat sink and fins are made of aluminum, and the PCM used is n-eicosane (C20 H42). The enthalpy-porosity method is used to model the solid–liquid phase change in the PCM. All the transient three-dimensional numerical simulations are carried out using ansys fluent 15.0. For a constant heat load of 5 W and power surges of various magnitudes at different time instants, the heat sink with vertical square fins shows superior performance. However, the performance variation among the heat sinks with different fin configurations is insignificant for constant heat load. Even so, for power surges, the location and the configuration of fins have a significant effect on the heater temperature. Cases with high power surge and shorter duration of the surge were also considered to critically examine the effect of fins in controlling the maximum temperature in the heat sink. The numerical results of the best-performing heat sink, i.e., the heat sink with vertical square fins, are finally validated against in-house experiments.

Author(s):  
Ingrid Cotoros ◽  
Ab Hashemi

A numerical model and analysis has been performed on a state-of-the art one shot heat sink including an eicosane/carbon nanotubes (CNT) system of nano-enhanced phase change material (NEPCM). The nanoparticles, dispersed in the PCM liquid phase, can form a network of interconnected ballistic heat transport lines, thus increasing the thermal conductivity of the PCM by almost two orders of magnitude. The results show that the heat sink can be operated with a 40% higher heat load, for an extra 42% time, or with a 29% lighter mass, before the electronics reach the allowable maximum temperature.


Author(s):  
Adeel Arshad ◽  
Mark Jabbal ◽  
Hamza Faraji ◽  
Pouyan Talebizadehsardari ◽  
Muhammad Anser Bashir ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2558 ◽  
Author(s):  
Preeti Singh ◽  
Sourav Khanna ◽  
Sanjeev Newar ◽  
Vashi Sharma ◽  
K. Reddy ◽  
...  

Phase change material (PCM) based passive cooling of photovoltaics (PV) can be highly productive due to high latent heat capacity. However, the low rate of heat transfer limits its usefulness. Thus, the presented work aims at the improvement in PV cooling by using finned PCM (FPCM) heat sinks. In the present study, PCM heat sink and FPCM heat sinks were investigated numerically for PV cooling and the extracted heat is used for space heating. 4 kWp PV, PV-PCM and PV-FPCM systems were studied under the weather conditions of Southeast of England. It was observed that the PCM heat sinks can drop the peak PV temperature by 13 K, whereas FPCM heat sinks can enhance the PV cooling by 19 K. The PCM heat sinks can increase the PV electrical efficiency from 13% to 14%. Moreover, the daily electricity generation can be boosted by 7% using PCM and 8% by using FPCM heat sinks. In addition, 7 kWh of thermal output was achieved using the FPCM heat sink, and the overall efficiency of system increased from 13% to 19%.


Author(s):  
Mohamed Emam ◽  
Mahmoud Ahmed ◽  
Shinichi Ookawara

In the current work, a hybrid system including Concentrated photovoltaic (CPV) and phase change material (PCM) as a heat sink is considered as a single module to achieve high solar conversion efficiency. The main objective is to accelerate the thermal dissipation with a longer thermal regulation period. Thus, a new CPV-PCM system using various configurations of the PCM heat sink and different combinations of PCMs is investigated. This study presents a numerical simulation of the effects of PCM materials and designs on the CPV-PCM system performance. To estimate the thermal performance of the new CPV-PCM system, a comprehensive 2-D model for CPV layers integrated with PCMs is developed. This model couples a thermal model for CPV layers and a thermo-fluid model that considers the phase-change phenomenon using the enthalpy method. The model is numerically simulated at different configurations and combinations of PCM with various ranges of phase transition temperatures. Three different configurations of PCMs are investigated: one with a single cavity, and two with parallel arrangements including three and five cavities. Results indicate that the use of PCM heat sinks with three and five cavities increases the heat transfer inside the PCM and achieves a significant reduction of the solar cell temperature compared with a single cavity CPV-PCM system. Furthermore, thermal regulation effect and temperature uniformity of the CPV-PCM system is enhanced by using various combinations of PCMs.


2016 ◽  
Vol 25 ◽  
pp. 1182-1190 ◽  
Author(s):  
Jesto Thomas ◽  
P.V.S.S. Srivatsa ◽  
S. Ramesh Krishnan ◽  
Rajesh Baby

2014 ◽  
Vol 1016 ◽  
pp. 764-768
Author(s):  
Chen Hao Wang ◽  
Meng Hao Chen ◽  
Jeng Der Huang ◽  
Chia Ray Chen

A numerical study of the effectiveness of phase change material (PCM) used on FORMOSAT-7 at the preliminary design phase is presented in this study. N-eicosane is used as the PCM for its melting temperature. To compare the performance of PCM, different messes of PCM are applied for high-power-dissipating component with short-duty-cycle. The results show that PCM can improve the thermal stability of component by not only moderating peak temperature for worst hot case but also preventing sudden temperature decrease when the power mode of component changed. However, mass addition of PCM reduces the duration of the maximum temperature and the minimum temperature due to the better thermal conductivity of solid phase. Therefore, an optimization of mass is suggested for the application of PCM.


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