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The model of the energy storage system: (a) latent heat thermal energy storage (LHTES) unit, (b) single tube with the nano-enhanced phase change material (NePCM) domain; (c) computational domain.
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![Figure 2. The experimental findings of Kumar et al. [29] and the...](profile/Wahiba-Yaici/publication/349951714/figure/fig3/AS:1000319290982403@1615506112070/The-experimental-findings-of-Kumar-et-al-29-and-the-numerical-computations-of-the_Q320.jpg)
A wavy shape was used to enhance the thermal heat transfer in a shell-tube latent heat thermal energy storage (LHTES) unit. The thermal storage unit was filled with CuO–coconut oil nano-enhanced phase change material (NePCM). The enthalpy-porosity approach was employed to model the phase change heat transfer in the presence of natural convection ef...
Contexts in source publication
Context 1
... multi-tube shell-and-tube LHTES unit, in which the NePCM is arranged in the shell side with an initial super cold temperature of Tinitial, and the hot fluid flows through the wavy tubes, as shown in Figure 1a. The tubes are placed next to each other. ...
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... tubes are placed next to each other. Here, one of the tubes (see Figure 1b) is selected for the investigation of melting heat transfer. The HTF with a high temperature is injected into the wavy tube with a temperature of Tin, the heat is transferred between the wavy wall and the NePCM, with thermal energy stored in the NePCM. ...
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... HTF with a high temperature is injected into the wavy tube with a temperature of Tin, the heat is transferred between the wavy wall and the NePCM, with thermal energy stored in the NePCM. A 2D axis symmetric view of the model is shown in Figure 1c. The PCM and the nanoadditives on the NePCM are the coconut oil and CuO nanoparticles, with the thermophysical characteristics listed in Table 1. ...
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... the configurations of a single tube along with the surrounding NePCM is axisymmetric, a two-dimensional (2D) configuration can be considered to save computational time, as shown in Figure 1c. As previously discussed, in detail, to model the melting front, the enthalpy-porosity method is employed. ...
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... results in an overall faster PCM melting and a greater volume of liquid PCM for A = 0. For these reasons, it is clear that reducing A shows a positive effect on both MVF and ES as indicated in Figure 10. The last control factor to be assessed is the number of undulations N of the wavy tube. ...
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... last control factor to be assessed is the number of undulations N of the wavy tube. The thermal and flow patterns of the PCM in the enclosure are shown in Figures 11 and 12 for two values of N, N = 4 (the optimal value) and N = 1, and for the highest wave amplitude of 3 mm. The flow streamlines mimic the wall profile near the hot tube, as the number of oscillations of the streamlines is equal to that of the tube. ...
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... volume of melted PCM, as well as the temperature in different zones of the cavity, are larger for N = 4 compared to N = 1, which can be attributed to the increase of surface contact between the PCM and the hot tube when the same amplitude is considered. This results in an increase of the MVF and the ES when N is raised, as observed in Figure 13. However, the presence of undulation entraps the fluid flow at the tube side and reduces the heat transfer. ...
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A latent heat thermal energy storage (LHTES) unit can store a notable amount of heat in a
compact volume. However, the charging time could be tediously long due to weak heat transfer. Thus, an improvement of heat transfer and a reduction in charging time is an essential task. The present research aims to improve the thermal charging of a conical sh...
Citations
... The governing equations for conservation of mass momentum for HTF flow can be explained as [42,43]: ...
... The conservation of mass is introduced as [42,43,45]: ...
... The conservation of energy is explained as [42,43,45]: ...
... The control equations for the flow and heat transfer of NPCM in metal foam [38][39][40]: ...
... The control equations for the flow and heat transfer of NPCM in metal foam [38][39][40]: The metal foam permeability is computed using the following relation [41,42]: ...
The dynamic melting of CuO–coconut oil was addressed in a latent-heat thermal energy storage unit loaded with copper foam. In a new design, the thermal storage unit is made of a shell-tube-shaped chamber, in which a liquid flow of hot phase-change material (PCM) is allowed to enter the chamber from a port at the bottom and exit at the top. A fin is mounted in the chamber to forward the entrance PCM liquid toward the solid regions. The control equations were solved using the finite element method. The impact of foam porosity, inlet pressure, fin length, and the concentrations of CuO nanoparticles on the thermal charging time of the chamber was investigated. A fast-charging time of 15 min with a foam porosity of 0.95 was achieved. A porosity of 0.95 can provide a maximum thermal charging power of 15.1 kW/kg. The inlet pressure was a significant parameter, and increasing the inlet pressure from 0.5 kPa to 4 kPa reduced the melting time by 2.6 times. The presence of the fin is not advantageous, and even a long fin could extend the thermal charging time. Moreover, dispersed nanoparticles were not beneficial to dynamic melting and extended the thermal charging time.
... PCM has teeny temperature variation during the phase change process, low melting, and high latent heat. 47,48 Moraga et al. 49 used four kinds of pure PCM to design a BTM to investigate the optimal number of layers and locations of PCMs. The study revealed that three layers of PCM is the optimal configuration where the PCMs with higher thermal conductivity should be placed closer to the battery while PCMs with lower thermal conductivity should be placed in the outer wall. ...
This paper presents a comprehensive review on the battery especially Lithium-ion batteries and the battery thermal management systems for electric vehicles. The basics of the battery system and thermal issues related to the battery have been highlighted. Different battery thermal management systems have been discussed in the review. This paper has presented different thermal management systems for electric vehicle battery in details. Air cooling, phase change, and liquid cooling are studied in the reviewed literature, by showing and discussing the results of the previous studies in these fields. Most promising thermal management system is the liquid cooling, because it has the best cooling potential for the EV batteries which gets the researchers attention to improve it based on wide number of increasing studies and developments in the EV liquid cooling systems. Improving the hydraulic and thermal performance of the liquid cold plate which is part of the EV liquid colling systems has not widely been explored in the fields of developing inlets design, outlets, and fins. The review paper could guide the researchers to innovate better liquid cooling systems and improve their cooling and hydraulic performance in battery thermal management systems.
Thermal energy storage (TES) occurs by changing the internal energy of materials in the form of sensible heat, latent heat, and thermo-chemical heat or a combination thereof. Latent heat storage (LHS) by phase change materials (PCMs) has many applications among these storage techniques. Despite the many advantages of LHS, the main problem of LHS systems using PCMs is their low thermal conductivity, which necessitates the combination of heat transfer enhancement techniques. Numerous diverse studies have utilized only one improvement method, while limited research has employed hybrid enhancement techniques. The typical improvement methods, such as adding nanomaterials, using fins, employing porous media, and micro/nano encapsulating the PCMs, can be combined in the TES system. A hybrid technique is when a combination of two or more enhancement methods is applied to a TES system. In addition, a new approach is introduced and then utilized in the hybrid enhancement method. An auxiliary fluid in direct contact with the PCM improves heat transfer in the melting and solidification processes. In this direction, this review discusses different enhancement strategies of melting and solidification rates in TES systems in recent years. The hybrid techniques introduced in this literature review show that the TES system performance has improved, further justifying the use of this method in future studies. Lastly, the challenges and future work direction are recommended, for exploring other hybrid enhancement methods for LHS systems.
