scholarly journals Estimating the state of charge in a latent thermal energy storage heat exchanger based on inlet/outlet and surface measurements

2021 ◽  
pp. 117806
Author(s):  
Wim Beyne ◽  
Kenny Couvreur ◽  
Ilya T'Jollyn ◽  
Steven Lecompte ◽  
Michel De Paepe
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
The State ◽  
State Of Charge ◽  
Surface Measurements

scholarly journals Evaluation of the State of Charge of a Solid/Liquid Phase Change Material in a Thermal Energy Storage Tank

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1425 ◽  
Author(s):  
Gabriel Zsembinszki ◽  
Christian Orozco ◽  
Jaume Gasia ◽  
Tilman Barz ◽  
Johann Emhofer ◽  
...  
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Residential Buildings ◽  
The State ◽  
State Of Charge ◽  
Accurate Estimation ◽  
Change Material

Monitoring of the state of charge of the thermal energy storage component in solar thermal systems for space heating and/or cooling in residential buildings is a key element from the overall system control strategy point of view. According to the literature, there is not a unique method for determining the state of charge of a thermal energy storage system that could generally be applied in any system. This contribution firstly provides a classification of the state-of-the-art of available techniques for the determination of the state of charge, and secondly, it presents an experimental analysis of different methods based on established sensor technologies, namely temperature, mass flow rates, and pressure measurements, tested using a lab-scale heat exchanger filled with a commercial phase change material for cooling applications. The results indicate that, depending on the expected accuracy and available instrumentation, each of the methods studied here can be used in the present application, the deviations between the methods generally being below 20%. This study concludes that a proper combination of two or more of these methods would be the ideal strategy to obtain a more reliable and accurate estimation of the state of charge of the latent heat thermal energy storage.

scholarly journals Thermal Energy Storage Performance of Tetrabutylammonium Acrylate Hydrate as Phase Change Materials

2021 ◽  
Vol 11 (11) ◽  
pp. 4848
Author(s):  
Hitoshi Kiyokawa ◽  
Hiroki Tokutomi ◽  
Shinichi Ishida ◽  
Hiroaki Nishi ◽  
Ryo Ohmura
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Solid Phase ◽  
Agitation Rate ◽  
Mechanical Agitation ◽  
External Forces

Kinetic characteristics of thermal energy storage (TES) using tetrabutylammonium acrylate (TBAAc) hydrate were experimentally evaluated for practical use as PCMs. Mechanical agitation or ultrasonic vibration was added to detach the hydrate adhesion on the heat exchanger, which could be a thermal resistance. The effect of the external forces also was evaluated by changing their rotation rate and frequency. When the agitation rate was 600 rpm, the system achieved TES density of 140 MJ/m3 in 2.9 hours. This value is comparable to the ideal performance of ice TES when its solid phase fraction is 45%. UA/V (U: thermal transfer coefficient, A: surface area of the heat exchange coil, V: volume of the TES medium) is known as an index of the ease of heat transfer in a heat exchanger. UA/V obtained in this study was comparable to that of other common heat exchangers, which means the equivalent performance would be available by setting the similar UA/V. In this study, we succeeded in obtaining practical data for heat storage by TBAAc hydrate. The data obtained in this study will be a great help for the practical application of hydrate heat storage in the future.

The Optimum Design of Stratified Thermal Energy Storage Systems—Part II: Completion of the Analytical Model, Presentation and Interpretation of the Results

1992 ◽  
Vol 114 (3) ◽  
pp. 204-208 ◽  
Author(s):  
R. J. Krane ◽  
M. J. M. Krane
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Analytical Model ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Thermal Energy Storage System ◽  
Thermal Energy Storage Systems ◽  
Performance Gains

This investigation is presented in two parts. The basic analytical model is developed in Part I. Part II includes the completion of the analytical model and the results of an optimization study performed with this model. The results show that: 1) Significant performance gains, that is, reductions in the entropy generation number on the order of 10 percent, are possible by employing perfectly stratified thermal energy storage systems that are designed on the basis of the second law of thermodynamics. 2) These performance gains are mainly due to the complete elimination of the entropy generation due to heat transfer through finite temperature differences within the storage element. 3) In general, the optimum design of a perfectly stratified thermal energy storage system requires the use of a very large heat exchanger; however, it is possible to employ a much smaller than optimum heat exchanger without seriously degrading the superior performance of the system. 4) The operation of a stratified system is quite flexible because it has no optimum storage time. 5) The optimum values of the capacity rate ratios, (φR)opt and (φR)opt, for a perfectly stratified thermal energy storage system are in general not equal to unity; however, this finding is shown to be in concert with Bejan’s theory of “remanent” irreversibilities for a heat exchanger.

scholarly journals Designs of PCM based heat exchangers constructions for thermal energy storage tanks – examples and case study for selected design

2018 ◽  
Vol 70 ◽  
pp. 01010
Author(s):  
Marta Kuta ◽  
Dominika Matuszewska ◽  
Tadeusz Michał Wójcik
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
New Technologies ◽  
Tube Heat Exchanger ◽  
Change Material

Increasing energy consumption in residential and public buildings requires development of new technologies for thermal energy production and storage. One of possibilities for the second listed need is the use of phase change materials (PCMs). This work is focused on solutions in this area and consists of two parts. First one is focused on different designs of thermal energy storage (TES) tanks based on the phase change materials. The second part is the analysis of tests results for TES tank containing shelf and tube heat exchanger and filled with phase change material. Thermal energy storage tank is analyzed in order to use it in domestic heating and hot utility water installations. The aim of this research was to check the applicability of phase change material for mentioned purpose. Results show that using phase change materials for thermal energy storage can increase amount of stored heat. The use of properly selected PCM and heat exchanger enables the process of thermal energy storing and releasing to become more efficient.

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