scholarly journals Experimental testing of various heat transfer structures in a flat plate thermal energy storage unit

Author(s):  
Maike Johnson ◽  
Michael Fiß ◽  
Torsten Klemm
2020 ◽  
Author(s):  
Addison Hockins ◽  
Samantha Moretti ◽  
Mahboobe Mahdavi ◽  
Saeed Tiari

Abstract Latent heat thermal energy storage (LHTES) systems are used to store thermal energy and release it for later use by melting or solidifying a phase change material (PCM). One problem associated with latent heat thermal energy storage systems is the low thermal conductivity of most commercially aviable phase change materials. This can have a significant negative effect on the thermal performance of the system by leading to a longer charging or discharging process. Several passive heat transfer enhancement techniques are used to resolve this issue. Common passive heat transfer enhancement techniques include inserting fins and extended surfaces into the PCM, embedding heat pipes or other two-phase heat transfer devices within the PCM, dispersion of highly conductive nanoparticles in the PCM, and impregnation of highly conductive porous media with the PCM. The current study analyzes the effect of a fin-based enhancement technique on the thermal performance of a latent heat thermal energy storage unit. Copper fins are attached annually around the central pipe inside the PCM. A transient two-dimensional numerical model technique is developed using ANSYS FLUENT 19.0 to simulate the operation of the system. Baseline tests have been conducted experimentally for a system without fins to validate the numerical model. The results obtained from the numerical modeling are in good agreement with those of the experimental testing. Based on the experimental testing, the total charging time of the system using hot water at 70°C and flow rate of 7.57 L/min is around 47.9 hours which is very close to the prediction by the numerical model which is 48 hours. Numerical modeling of the system with 10 fins and 20 fins found that the charging time was decreased by 68.9% and 73.7%, respectively. The discharging time was also decreased by 73.2% and 79.1%, respectively.


2017 ◽  
Vol 142 ◽  
pp. 576-581 ◽  
Author(s):  
Leyla Amiri ◽  
Seyed Ali Ghoreishi-Madiseh ◽  
Agus P. Sasmito ◽  
Ferri P. Hassani

2018 ◽  
Vol 152 ◽  
pp. 984-989 ◽  
Author(s):  
Jiabang Yu ◽  
Ying Yang ◽  
Xiaohu Yang ◽  
Qiongxiang Kong ◽  
Liu Yanhua ◽  
...  

2021 ◽  
Vol 11 (19) ◽  
pp. 8972
Author(s):  
Valeria Palomba ◽  
Andrea Frazzica

In the present paper, the numerical modeling of an innovative latent thermal energy storage unit, suitable for direct integration into the condenser or evaporator of a heat pump is presented. The Modelica language, in the Dymola environment, and TIL libraries were used for the development of a modular model, which is easily re-usable and adaptable to different configurations. Validation of the model was carried out using experimental data under different operating modes and it was subsequently used for the optimization of a design for charging and discharge. In particular, since the storage unit is made up of parallel channels for the heat transfer fluid, refrigerant, and phase change material, their number and distribution were changed to evaluate the effect on heat transfer performance.


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