Analysis of a New Hybrid Water-Phase Change Material Heat Sink for Low Concentrated Photovoltaic Systems

2017 ◽  
Author(s):  
Mohamed Emam ◽  
Ali Radwan ◽  
Mahmoud Ahmed
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Water Flow ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Water System ◽  
High Energy ◽  
Heat Extraction ◽  
Night Time ◽  
Change Material

Concentrated photovoltaic (CPV) integrated with phase-change material (CPV-PCM) system is considered as a single module to reduce the CPV temperature rise and achieve higher solar conversion efficiency. For low concentration ratios (CRs), up to 20, a larger PCM thickness is needed to absorb much more heat and prolong the thermal regulation time of CPV systems. As a result, the heat absorbed in the PCM is not released efficiently to the ambient during the night time. Therefore, active heat dissipation from the CPV-PCM system is required during that time to attain full transition to solid state at the starting of each period of insolation. Thus, a hybrid CPV-PCM water system including various designs of the PCM heat sink is proposed. Such system provides a high-energy storage density during the daytime and enhances the heat extraction from PCM during the night time. To predict the thermal and electrical performance of the hybrid CPV-PCM water system, a comprehensive 2-D model for CPV layers integrated with both PCM, and water flow is developed. The model couples thermal models for CPV layers and thermo-fluid model that considers the phase-change phenomenon and water flow. Numerical simulations of the developed models are performed to determine the instantaneous liquid-solid interface evolution and the transient temperature distribution within the hybrid CPV-PCM water system. Results indicate that the hybrid CPV-PCM water system achieves a significant reduction in the CPV temperature during the daytime and improves the heat dissipation from PCM during the night time.

Design and Testing of Passive Sensor Cooling Using Phase Change Material

2005 ◽  
Author(s):  
Julie Pecson ◽  
Craig Perkins ◽  
Ab Hashemi
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Laser Diode ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Heat Sinks ◽  
Analytical Models ◽  
Manufacturing Testing ◽  
Metal Casing ◽  
Change Material

Passive heat rejection from a weapon system deployed in space is a challenging problem. This paper describes the development of a phase-change material mini heat sink to absorb the heat from a laser diode for the required operational scenario. Three mini heat sinks made of aluminum, copper, and copper tungsten were designed and manufactured. Phase change material (PCM) was selected to accommodate required heat dissipation from a laser diode. Metal fins, attached to the metal casing of the heat sink, were placed into the PCM to uniformly spread the heat and achieve effective heat transfer. Analytical models were developed to predict the performance of the heat sink. The heat sink was manufactured and initially tested in the laboratory with simulated heat load. Then, tests were carried out under prototypical conditions and the performance of the sink was demonstrated. A comparison of the analytical predictions with data also showed excellent agreement. This paper presents the design, modeling, manufacturing, testing, and comparison of the predictions with experimental results.

Cooling Management of Highly Powered Chips Packed in an Insulated Cavity Filled with a Phase Change Material

2010 ◽  
Vol 7 (2) ◽  
pp. 79-89 ◽  
Author(s):  
Mustapha Faraji
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Heat Sink ◽  
Phase Change Materials ◽  
Operating Time ◽  
Thermal Control ◽  
Numerical Approach ◽  
High Energy ◽  
The Impact ◽  
Change Material

This work describes and analyses a novel computer's thermal management system based on a phase change material (PCM) heat storage reservoir. The proposed heat sink consists of a PCM filled enclosure heated by substrate-mounted protruding heat sources (micro processors). PCMs, characterized by high energy storage density and small transition temperature interval, are able to store a high amount of generated heat; which provides a passive cooling of microprocessors. The advantage of this cooling strategy is that the phase change materials are able to absorb a high amount of generated heat without energizing the fan. The proposed strategy is suitable and efficient for situations where the cooling by air convection is not practical (thermal control of recent multiprocessors computers, for example). The problem is modelled as, two dimensional, time dependent and convection–dominated phenomena. A finite volume numerical approach is developed and used to simulate the physical details of the problem. This approach is based on the enthalpy method which is traditionally used to track the motion of the liquid/solid front and obtain the temperature and velocity profiles in the liquid phase. The study gives an instruction on the presentation of PCM heat sink used for cooling management of recent computers. Numerical investigations have been conducted in order to examine the impact of several parameters on the thermal behaviour and efficiency of the proposed PCM-based heat sink. Correlation for the secured operating time (time required by the heat sink before reaching the critical temperature, Tcr) is developed.

Genetic Algorithm Based Optimization of PCM Based Heat Sinks and Effect of Heat Sink Parameters on Operational Time

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Atul Nagose ◽  
Ankit Somani ◽  
Aviral Shrot ◽  
Arunn Narasimhan
Keyword(s):  
Genetic Algorithm ◽  
Phase Change ◽  
Phase Change Material ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Optimal Solution ◽  
Constant Heat ◽  
Heat Spreader ◽  
Change Material ◽  
Operational Time

Using an approach that couples genetic algorithm (GA) with conventional numerical simulations, optimization of the geometric configuration of a phase-change material based heat sink (PBHS) is performed in this paper. The optimization is done to maximize the sink operational time (SOT), which is the time for the top surface temperature of the PBHS to reach the critical electronics temperature (CET). An optimal solution for this complex multiparameter problem is sought using GA, with the standard numerical simulation seeking the SOT forming a crucial step in the algorithm. For constant heat dissipation from the electronics (constant heat flux) and for three typical PBHS depths (A), predictive empirical relations are deduced from the GA based simulation results. These correlations relate the SOT to the amount of phase change material to be used in the PBHS (φ), the PBHS depth (A), and the heat-spreader thickness (s), a hitherto unconsidered variable in such designs, to the best of the authors’ knowledge. The results show that for all of the typical PBHS depths considered, the optimal heat-spreader thickness is 2.5% of the PBHS depth. The developed correlations predict the simulated results within 4.6% for SOT and 0.32% for ϕ and empowers one to design a PBHS configuration with maximum SOT for a given space restriction or the most compact PBHS design for a given SOT.

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.

Comparison of Stratification in a Water Tank and a PCM-Water Tank

2007 ◽  
Author(s):  
A. Castell ◽  
C. Sole´ ◽  
M. Medrano ◽  
M. Nogue´s ◽  
L. F. Cabeza
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Temperature Change ◽  
High Energy ◽  
Hot Water ◽  
The Other ◽  
High Energy Density ◽  
Water Tank ◽  
Charging And Discharging Processes ◽  
Change Material

Most of the storage systems available on the market use water as storage medium. Enhancing the storage performance is necessary to increase the performance of most systems. The stratification phenomenon is employed to improve the efficiency of storage tanks. Heat at an intermediate temperature, not high enough to heat up the top layer, can still be used to heat the lower, colder layers. There are a lot of parameters to study the stratification in a water tank such as the Mix Number and the Richardson Number among others. The idea studied here was to use these stratification parameters to compare two tanks with the same dimensions during charging and discharging processes. One of them is a traditional water tank and the other is a PCM-water (a water tank with a Phase Change Material). A PCM is good because it has high energy density if there is a small temperature change, since then the latent heat is much larger than the sensible heat. On the other hand, the temperature change in the top layer of a hot water store with stratification is usually small as it is held as close as possible at or above the temperature for usage. In the system studied the Phase Change Material is placed at the top of the tank, therefore the advantages of the stratification still remain. The aim of this work is to demonstrate that the use of PCM in the upper part of a water tank holds or improves the benefit of the stratification phenomenon.

Thermal performance of a phase change material-based heat sink in presence of nanoparticles and metal-foam to enhance cooling performance of electronics

2022 ◽  
Vol 48 ◽  
pp. 103882
Author(s):  
Adeel Arshad ◽  
Mark Jabbal ◽  
Hamza Faraji ◽  
Pouyan Talebizadehsardari ◽  
Muhammad Anser Bashir ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Thermal Performance ◽  
Heat Sink ◽  
Metal Foam ◽  
Cooling Performance ◽  
Change Material

Operational Time and Melt Fraction Based Optimization of a Phase Change Material Longitudinal Fin Heat Sink

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
D. Jaya Krishna
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Heat Sink ◽  
Fluid Model ◽  
Melting Behavior ◽  
Base Temperature ◽  
Critical Temperatures ◽  
Volume Of Fluid Model ◽  
Change Material ◽  
Operational Time

Abstract In the present study, the numerical investigation has been performed for a phase change material (PCM)-based longitudinal fin heat sink. The fins are taken as an integral part of the heat sink and are made up of aluminum. The PCM considered in the study is RT44HC. Heat is transferred to the heat sink through its horizontal base. In order to simulate the melting behavior of the PCM, volume of fluid model has been used. To attain the best configuration with optimum operational time, Taguchi method has been used followed by analysis of melt fraction and maximum base temperature. The optimized heat sink configuration with maximum operational time has been obtained at the critical temperatures of 54.8 °C, 63 °C, and 72.6 °C.

Sign in / Sign up

Export Citation Format

Share Document