Performance Enhancement of Phase Change Thermal Energy Storage Unit Using Fin and Copper Foam

2012 ◽  
Vol 260-261 ◽  
pp. 137-141 ◽  
Author(s):  
Yong Qi Xie ◽  
Jun Song ◽  
Peng Tao Chi ◽  
Jian Zu Yu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Performance Enhancement ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Copper Foam

An experimental study has been carried out to evaluate how fin and copper foam enhance the heat transfer performance of phase change thermal energy storage unit. The thickness of fins is 0.8mm, the porosity of the copper foam is 96% and the phase change material (PCM) is 99% pure eicosane. The samples with fin, copper foam and paraffin (FCFP) or with single copper foam and paraffin (CFP) were processed and their response to temperature variations were tested for vertical placement and horizontal placement under different heat flux conditions. The experimental results show that the use of fin and copper foam can make the sample melt much faster than single copper foam and the effective thermal conductivity of the FCFP composite is 10.83 W/(m∙K), which is 2.7 times as that of the CFP composite. In addition, horizontal placement is more contributive to the heat transfer than vertical placement for high thermal conductivity composite.

scholarly journals Phase-Transition Thermal Charging of a Channel-Shape Thermal Energy Storage Unit: Taguchi Optimization Approach and Copper Foam Inserts

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1235
Author(s):  
Mohammad Ghalambaz ◽  
Seyed Abdollah Mansouri Mehryan ◽  
Ahmad Hajjar ◽  
Obai Younis ◽  
Mikhail A. Sheremet ◽  
...  
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Metal Foam ◽  
Volume Fraction ◽  
Foam Layer ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Copper Foam

Thermal energy storage is a technique that has the potential to contribute to future energy grids to reduce fluctuations in supply from renewable energy sources. The principle of energy storage is to drive an endothermic phase change when excess energy is available and to allow the phase change to reverse and release heat when energy demand exceeds supply. Unwanted charge leakage and low heat transfer rates can limit the effectiveness of the units, but both of these problems can be mitigated by incorporating a metal foam into the design of the storage unit. This study demonstrates the benefits of adding copper foam into a thermal energy storage unit based on capric acid enhanced by copper nanoparticles. The volume fraction of nanoparticles and the location and porosity of the foam were optimized using the Taguchi approach to minimize the charge leakage expected from simulations. Placing the foam layer at the bottom of the unit with the maximum possible height and minimum porosity led to the lowest charge time. The optimum concentration of nanoparticles was found to be 4 vol.%, while the maximu possible concentration was 6 vol.%. The use of an optimized design of the enclosure and the optimum fraction of nanoparticles led to a predicted charging time for the unit that was approximately 58% shorter than that of the worst design. A sensitivity analysis shows that the height of the foam layer and its porosity are the dominant variables, and the location of the porous layer and volume fraction of nanoparticles are of secondary importance. Therefore, a well-designed location and size of a metal foam layer could be used to improve the charging speed of thermal energy storage units significantly. In such designs, the porosity and the placement-location of the foam should be considered more strongly than other factors.

scholarly journals Effect of the Quasi-Petal Heat Transfer Tube on the Melting Process of the Nano-Enhanced Phase Change Substance in a Thermal Energy Storage Unit

2021 ◽  
Vol 13 (5) ◽  
pp. 2871
Author(s):  
Mohammad Ghalambaz ◽  
Seyed Abdollah Mansouri Mehryan ◽  
Reza Kalantar Feeoj ◽  
Ahmad Hajjar ◽  
Obai Younis ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Capric Acid ◽  
Melting Time ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Petal Shape

The melting heat transfer of nano-enhanced phase change materials was addressed in a thermal energy storage unit. A heated U-shape tube was placed in a cylindrical shell. The cross-section of the tube is a petal-shape, which can have different amplitudes and wave numbers. The shell is filled with capric acid with a fusion temperature of 32 °C. The copper (Cu)/graphene oxide (GO) type nanoparticles were added to capric acid to improve its heat transfer properties. The enthalpy-porosity approach was used to model the phase change heat transfer in the presence of natural convection heat transfer effects. A novel mesh adaptation method was used to track the phase change melting front and produce high-quality mesh at the phase change region. The impacts of the volume fraction of nanoparticles, the amplitude and number of petals, the distance between tubes, and the angle of tube placements were investigated on the thermal energy rate and melting-time in the thermal energy storage unit. An average charging power can be raised by up to 45% by using petal shape tubes compared to a plain tube. The nanoadditives could improve the heat transfer by 7% for Cu and 11% for GO nanoparticles compared to the pure phase change material.

scholarly journals Melting phase change heat transfer in a quasi-petal tube thermal energy storage unit

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0246972
Author(s):  
S. A. M. Mehryan ◽  
Kaamran Raahemifar ◽  
Sayed Reza Ramezani ◽  
Ahmad Hajjar ◽  
Obai Younis ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Circular Tube ◽  
Adaptive Mesh ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Phase Change Heat Transfer

In the present study, the thermal energy storage of a hot petal tube inside a shell-tube type Thermal Energy Storage (TES) unit was addressed. The shell is filled with the capric acid Phase Change Material (PCM) and absorbs the heat from a hot U-tube petal. The governing equations for the natural convection flow of molten PCM and phase change heat transfer were introduced by using the enthalpy-porosity approach. An automatic adaptive mesh scheme was used to track the melting interface. The accuracy and convergence of numerical computations were also controlled by a free step Backward Differentiation Formula. The modeling results were compared with previous experimental data. It was found that the present adaptive mesh approach can adequately the melting heat transfer, and an excellent agreement was found with available literature. The effect of geometrical designs of the petal tube was investigated on the melting response of the thermal energy storage unit. The phase change behavior was analyzed by using temperature distribution contours. The results showed that petal tubes could notably increase the melting rate in the TES unit compared to a typical circular tube. Besides, the more the petal numbers, the better the heat transfer. Using a petal tube could increase the charging power by 44% compared to a circular tube. The placement angle of the tubes is another important design factor which should be selected carefully. For instance, vertical placement of tubes could improve the charging power by 300% compared to a case with the tubes’ horizontal placement.

scholarly journals Optimization of the Melting Performance of a Thermal Energy Storage Unit with Fractal Net Fins

Processes ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 42 ◽  
Author(s):  
Jiayi Zheng ◽  
Cheng Yu ◽  
Taotao Chen ◽  
Yanshun Yu ◽  
Fang Wang
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Liquid Fraction ◽  
Storage Unit ◽  
Melting Heat ◽  
Energy Storage Unit ◽  
Melting Heat Transfer

In this study, fractal net fins were introduced to improve the melting performance of a thermal energy storage unit. A transient model for melting heat transfer for phase change material (PCM) was presented and numerically analyzed, to study the melting performance in a thermal energy storage unit using fractal net fins. The melting phase change process was modelled using the apparent heat capacity method. The evolutions of temperature and the liquid fraction in the thermal energy storage unit were investigated and discussed. The effects of the length and width ratios of the fractal net on melting performance were analyzed to obtain the optimal fin configuration. The results indicated that the fractal net fins significantly enhanced the melting heat transfer performance of the PCM in a thermal energy storage unit. The fractal net fins configuration was optimal when the length and width ratios of the fractal net were 0.5. The temperature response at the corner points of the fractal net fins was faster than that in the central points.

scholarly journals FAZINIO VIRSMO MEDŽIAGOS CHARAKTERISTIKŲ ŠILUMOS KAUPIKLYJE SKAITINIS MODELIAVIMAS / SIMULATION OF THE PHASE CHANGE MATERIALS’ CHARACTERISTICS IN A THERMAL ENERGY STORAGE

2018 ◽  
Vol 10 (0) ◽  
pp. 1-7 ◽  
Author(s):  
Saulius Pakalka ◽  
Kęstutis Valančius ◽  
Giedrė Streckienė ◽  
Vaidvilė Ulbikaitė
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Heat Transfer Process ◽  
Comsol Multiphysics ◽  
Storage Unit ◽  
Energy Storage Unit

In order to use efficiently residual, waste or renewable energy, the application of phase change materials (PCM) grows in building energy systems. At the same time, this poses new technological challenges in choosing specific materials, system design solutions, because it requires a specific knowledge of the heat transfer process during the phase change. The aim of the work is to investigate the heat transfer in a PCM based thermal energy storage unit using the COMSOL Multiphysics software. In the analysis, the properties of the material were evaluated during the phase change. This allowed to determine that the thermal conductivity of the material is of great importance for the intensification of heat transfer. In addition, the analysis of several points in the analyzed object revealed that the phase change does not occur in the surface layer of the PCM during the period under consideration. In order to avoid that, additional solutions such as integrating heat-conductive materials into the PCM or increasing the surface area of the heat transfer could be used. Santrauka Siekiant efektyviai išnaudoti perteklinę, atliekinę ar atsinaujinančių energijos išteklių gaminamą energiją, vis dažniau taikomas fazinio virsmo medžiagų (FVM) panaudojimas pastato energetinėse sistemose. Kartu tai kelia naujus technologinius iššūkius pasirenkant konkrečias medžiagas, sistemų projektinius sprendinius, nes reikia gerai išmanyti šilumos mainų procesą vykstant fazės virsmui. Šiame darbe siekiama ištirti šilumos mainus šilumos kaupiklyje su fazinio virsmo medžiagomis naudojantis COMSOL Multiphysics programa. Analizės metu įvertintos medžiagos savybės vykstant fazės virsmui. Tai leido nustatyti, kad medžiagos šilumos laidumo koeficientas turi didelę reikšmę šilumos mainų intensyvinimui. Be to, atskirų taškų analizė tyrimo objekte atskleidė, kad per nagrinėjamąjį laikotarpį FVM paviršiniame sluoksnyje fazės virsmas neįvyksta. Siekiant to išvengti, galimi papildomi sprendimai, tokie kaip šilumai laidžių medžiagų integravimas į FVM arba šilumos mainų paviršiaus ploto didinimas.

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