scholarly journals Experimental and Numerical Study for a Novel Arrangement of a SuperCapacitors Stack to Improve Heat Transfer

2022 ◽  
Vol 12 (2) ◽  
pp. 662
Author(s):  
Ionut Victor Voicu ◽  
Florin Bode ◽  
Wassim Abboud ◽  
Hasna Louahlia ◽  
Hamid Gualous ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Energy Storage ◽  
Forced Convection ◽  
Electrical Energy ◽  
Maximum Temperature ◽  
Temperature Deviation ◽  
Electrical Energy Storage ◽  
Improve Heat Transfer ◽  
The Impact

Supercapacitors (SCs) are electrical energy storage devices which have the peculiarity of storing more electrical energy than capacitors and supply it at higher power outputs than batteries. This, together with the fact that the SCs have high cyclability and long-term stability, make them very attractive devices for electrical energy storage. Thermal transfer around a novel arrangement of a module of five rows of SCs is approached in this paper. A mixed aligned/staggered configuration is studied, aiming to explore a new possibility that can improve heat transfer more than other configurations studied before in the literature. The maximum SC current rate current is 84 A and the maximum temperature is 65 °C. The module undergoes charge and discharge cycles. The current tests are performed up to 50 A for natural convection and up to 70 A in forced convection. For the natural convection case, the SC located in the center of module is the most critical from the temperature point of view and the temperature evolution shows the necessity of a cooling system. The relative temperature reaches 27 °C for 50 A and the permanent regime cannot be reached with a current greater than 50 A. Thereafter, the impact of position and current on the temperature of SCs in forced convection is examined. The airflow mean air velocity is 0.69 m/s. The temperature of the SCs located on the third and fourth row are very close. However, the last row is the least cooled. This low temperature rise can be explained by the change from an aligned to a staggered arrangement between these rows. Compared to the natural convection case, a significant decrease is observed for the relative temperatures. The difference between the highest and lowest temperature augmentation also decrease but remain high. The temperature difference becomes greater than 5 °C if continuous current exceeds 39 A. CFD numerical simulation is performed for steady state at maximum experimental current rate in order to better understand the thermal and flow behavior. Numerical and experimental results are in good agreement, with a temperature deviation of less than 10%.

scholarly journals Assessment of Electricity Decarbonization Scenarios for New Zealand and Great Britain using a Plant Dispatch and Electrical Energy Storage Modelling Framework

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2799
Author(s):  
Andrew Crossland ◽  
Keith Scoles ◽  
Allen Wang ◽  
Chris Groves ◽  
Susan Sun
Keyword(s):  
New Zealand ◽  
Great Britain ◽  
Energy Storage ◽  
Electricity Generation ◽  
Fossil Fuel ◽  
Electrical Energy ◽  
Potential Contribution ◽  
Electrical Energy Storage ◽  
The Impact ◽  
Electricity Systems

This paper proposes a methodology to assess the impact of alternative electricity generation and energy storage scenarios for meeting electricity demand on a national level. The method combines real and synthetic electricity generation and demand data to investigate different decarbonization strategies using solar and wind generation and electrical energy storage. This method is applied to provide relevant case studies for two geographically similar electricity systems in New Zealand and Great Britain. Newly available solar and wind data sets at hourly resolution are used within this method for these systems to assess the potential contribution of these technologies and as such, to refresh understanding of the impact of these technologies on decarbonization strategies against historical and future demand patterns. Although wind, solar and storage technologies are found to reduce the carbon emissions in both electricity systems, a key result is quantifying the impact this has on traditional generation as a backup resource. In New Zealand an investment in wind and solar equivalent to less than 15% of the wind/solar capacity in Great Britain is found to (i) reduce fossil fuel use to less than 2% of annual electricity generation requirements in the data assessed and (ii) remove the need for continuous operation of fossil fuel plants. Further, it is shown that existing hydro storage potential could be used to create near complete decarbonization of New Zealand electricity

Experimental Determination of the Forced-Convection Gas-to-Wall Heat Transfer Coefficient in a Packed Bed for High Temperature Thermal Energy Storage

2001 ◽  
Author(s):  
Emmanuel C. Nsofor ◽  
George A. Adebiyi
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
High Temperature ◽  
Energy Storage ◽  
Transfer Coefficient ◽  
Forced Convection ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Packed Bed ◽  
Maximum Temperature

Abstract Measurements of the gas-to-wall forced convection heat transfer coefficient in a packed bed, high-temperature, thermal energy storage system were carried out. The maximum temperature attained was 1000°C. Effects of media property variations with temperature were incorporated along with detailed uncertainty analysis. Results were correlated in terms of Nusselt number, Prandtl number and Reynolds number. The operating fluid during energy storage was flue gas and air during recovery, making this more applicable to industrial waste recovery and similar systems. Similar studies used air for both storage and recovery and developed correlations from experiments at either room temperature or slightly above. Few associated results with corresponding uncertainty margins. Due to substantial uncertainties associated with the measurements of this heat transfer coefficient, it is significant to note that no firm conclusions can be reached on the validity or otherwise of existing similar correlations for which the uncertainty margins were not reported.

Mixed Convection Transport From an Isolated Heat Source Module on a Horizontal Plate

1990 ◽  
Vol 112 (3) ◽  
pp. 653-661 ◽  
Author(s):  
B. H. Kang ◽  
Y. Jaluria ◽  
S. S. Tewari
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Mixed Convection ◽  
Forced Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Finite Thickness ◽  
Forced Flow ◽  
Maximum Temperature ◽  
Convection Dominated

An experimental study of the mixed convective heat transfer from an isolated source of finite thickness, located on a horizontal surface in an externally induced forced flow, has been carried out. This problem is of particular interest in the cooling of electronic components and also in the thermal transport associated with various manufacturing systems, such as ovens and furnaces. The temperature distribution in the flow as well as the surface temperature variation are studied in detail. The dependence of the heat transfer rate on the mixed convection parameter and on the thickness of the heated element or source, particularly in the vicinity of the source, is investigated. The results obtained indicate that the heat transfer rate and fluid flow characteristics vary strongly with the mixed convection variables. The transition from a natural convection dominated flow to a forced convection dominated flow is studied experimentally and the basic characteristics of the two regimes determined. This transition has a strong influence on the temperature of the surface and on the heat transfer rate. As expected, the forced convection dominated flow is seen to be significantly more effective in the cooling of a heat dissipating component than a natural convection dominated flow. The location of the maximum temperature on the module surface, which corresponds to the minimum local heat transfer coefficient, is determined and discussed in terms of the underlying physical mechanisms. The results obtained are also compared with these for an element of negligible thickness and the effect of a significant module thickness on the transport is determined. Several other important aspects of fundamental and applied interest are studied in this investigation.

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