scholarly journals Effect of Twisted Fin Array in a Triple-Tube Latent Heat Storage System during the Charging Mode

2021 ◽  
Vol 13 (5) ◽  
pp. 2685
Author(s):  
Mohammad Ghalambaz ◽  
Jasim M. Mahdi ◽  
Amirhossein Shafaghat ◽  
Amir Hossein Eisapour ◽  
Obai Younis ◽  
...  
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Latent Heat ◽  
Thermal Energy ◽  
Heat Storage ◽  
Hot Water ◽  
Melting Time ◽  
Latent Heat Storage ◽  
Tube Heat Exchanger ◽  
Storage Rate

This study aims to assess the effect of adding twisted fins in a triple-tube heat exchanger used for latent heat storage compared with using straight fins and no fins. In the proposed heat exchanger, phase change material (PCM) is placed between the middle annulus while hot water is passed in the inner tube and outer annulus in a counter-current direction, as a superior method to melt the PCM and store the thermal energy. The behavior of the system was assessed regarding the liquid fraction and temperature distributions as well as charging time and energy storage rate. The results indicate the advantages of adding twisted fins compared with those of using straight fins. The effect of several twisted fins was also studied to discover its effectiveness on the melting rate. The results demonstrate that deployment of four twisted fins reduced the melting time by 18% compared with using the same number of straight fins, and 25% compared with the no-fins case considering a similar PCM mass. Moreover, the melting time for the case of using four straight fins was 8.3% lower than that compared with the no-fins case. By raising the fins’ number from two to four and six, the heat storage rate rose 14.2% and 25.4%, respectively. This study presents the effects of novel configurations of fins in PCM-based thermal energy storage to deliver innovative products toward commercialization, which can be manufactured with additive manufacturing.

scholarly journals Interaction between Organic and Inorganic PCMs and Selected Metals

2019 ◽  
Author(s):  
Sylva Bantová ◽  
Milan Ostrý ◽  
Karel Struhala
Keyword(s):  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Prolonged Exposure ◽  
Gravimetric Method ◽  
Hot Water ◽  
Storage Medium ◽  
Latent Heat Storage

Phase Change Materials (PCMs) are latent heat storage media with high potential of integration in building structures and technical systems. Their solid-liquid transition is commonly utilized for thermal energy storage in building applications. It also means that some kind of encapsulation is necessary. This is often solved with metal containers that also have high thermal conductivity and resistance to mechanical damage enhancing the performance these so called latent heat thermal energy storage (LHTES) systems. However selection of suitable metal is rather challenging. It depends, among other things, on the elimination of undesirable interaction between storage medium and surrounding metal. Heat storage medium must be reliably sealed in metal container especially when the storage system is integrated in systems like domestic hot water storage tanks, where PCM leaks can negatively affect human health. The aim of this study was evaluation of interaction between selected commercially available organic and inorganic PCMs and metals. The evaluation is based on the calculation of corrosion rate and use gravimetric method for determination of the weigh variations of the metal samples. Results show that aluminium is the most suitable container material with lowest mass loss and suffered only minimal visual changes on the surface after prolonged exposure to PCMs.

Quasi-stationary modelling of solidification in a latent heat storage comprising a plain tube heat exchanger

2018 ◽  
Vol 20 ◽  
pp. 551-559 ◽  
Author(s):  
A. Stamatiou ◽  
S. Maranda ◽  
F. Eckl ◽  
P. Schuetz ◽  
L. Fischer ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Heat Storage ◽  
Latent Heat Storage ◽  
Tube Heat Exchanger ◽  
Plain Tube

Remote Measurement and Heat Demand Control of CHP System With Heat Storage at Sapporo City University

2010 ◽  
Author(s):  
Osamu Kurata ◽  
Norihiko Iki ◽  
Takayuki Matsunuma ◽  
Tetsuhiko Maeda ◽  
Satoshi Hirano ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Heat Supply ◽  
Heat Storage ◽  
Hot Water ◽  
Exhaust Gas ◽  
Latent Heat Storage ◽  
Boiler Water ◽  
Heat Demand ◽  
Partial Load

Combined heat and power (CHP) systems are widely used to prevent global warming and reduce energy costs. Both high efficiency of the elements and good coordination of the systems are considered as the points to solve. A microturbine CHP with a latent heat storage system was demonstrated at Sapporo City University. The heat exchanger of the CHP and an economizer were located in parallel downstream a bypass-dumper of the exhaust gas. The latent heat storage tank was located downstream the economizer. The bypass-dumper released exhaust gas when the boiler water in the heat exchanger exceeded 90°C. It is very important to use the heat supply of hot water as much as possible. At Sapporo City University, the winter term heat demand from 6pm to 7pm was somewhat smaller than that from 8am to 6pm. We tested a partial load from 6pm to 7pm to observe how it would respond to the heat demand. The heat supply from the microturbine CHP from 6pm to 7pm was shown to be controllable with heat storage. The heat supply from the microturbine CHP at the lowest power was larger than the heat demand so without the heat storage it was uncontrollable.

Second-Law Efficiency of an Energy Storage-Removal Cycle in a Phase-Change Material Shell-and-Tube Heat Exchanger

1993 ◽  
Vol 115 (4) ◽  
pp. 240-243 ◽  
Author(s):  
Ch. Charach
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Latent Heat ◽  
Heat Storage ◽  
Latent Heat Storage ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Change Material

This communication extends the thermodynamic analysis of latent heat storage in a shell-and-tube heat exchanger, developed recently, to the complete heat storage-removal cycle. Conditions for the cyclic operation of this system are formulated within the quasi-steady approximation for the axisymmetric two-dimensional conduction-controlled phase change. Explicit expressions for the overall number of entropy generation units that account for heat transfer and pressure drop irreversibilities are derived. Optimization of this figure of merit with respect to the freezing point of the phase-change material and with respect to the number of heat transfer units is analyzed. When the frictional irreversibilities of the heat removal stage are negligible, the results of these studies are in agreement with those developed recently by De Lucia and Bejan (1991) for a one-dimensional latent heat storage system.

scholarly journals Review on the Integration of Phase Change Materials in Building Envelopes for Passive Latent Heat Storage

2021 ◽  
Vol 11 (19) ◽  
pp. 9305
Author(s):  
Mohamed Sawadogo ◽  
Marie Duquesne ◽  
Rafik Belarbi ◽  
Ameur El Amine Hamami ◽  
Alexandre Godin
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Storage Systems ◽  
Latent Heat Storage ◽  
Building Envelopes

Latent heat thermal energy storage systems incorporate phase change materials (PCMs) as storage materials. The high energy density of PCMs, their ability to store at nearly constant temperature, and the diversity of available materials make latent heat storage systems particularly competitive technologies for reducing energy consumption in buildings. This work reviews recent experimental and numerical studies on the integration of PCMs in building envelopes for passive energy storage. The results of the different studies show that the use of PCMs can reduce the peak temperature and smooth the thermal load. The integration of PCMs can be done on the entire building envelope (walls, roofs, windows). Despite many advances, some aspects remain to be studied, notably the long-term stability of buildings incorporating PCMs, the issues of moisture and mass transfer, and the consideration of the actual use of the building. Based on this review, we have identified possible contributions to improve the efficiency of passive systems incorporating PCMs. Thus, fatty acids and their eutectic mixtures, combined with natural insulators, such as vegetable fibers, were chosen to make shape-stabilized PCMs composites. These composites can be integrated in buildings as a passive thermal energy storage material.

Microstructure and thermal characteristics of Mg–Sn alloys as phase change materials for thermal energy storage

RSC Advances ◽  
2016 ◽  
Vol 6 (98) ◽  
pp. 96327-96333 ◽  
Author(s):  
Dong Fang ◽  
Xiaomin Cheng ◽  
Yuanyuan Li ◽  
Zheng Sun
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Thermal Characteristics ◽  
Latent Heat Storage

Latent heat storage proves to be one of the most efficient ways of storing thermal energy.

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