Thermal energy storage systems for district heating and cooling

2015 ◽  
pp. 467-478 ◽  
Author(s):  
H. Gadd ◽  
S. Werner
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Systems ◽  
District Heating ◽  
Energy Storage Systems ◽  
Heating And Cooling ◽  
Thermal Energy Storage Systems

scholarly journals A Modelica Toolbox for the Simulation of Borehole Thermal Energy Storage Systems

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2327 ◽  
Author(s):  
Julian Formhals ◽  
Hoofar Hemmatabady ◽  
Bastian Welsch ◽  
Daniel Schulte ◽  
Ingo Sass
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Systems ◽  
District Heating ◽  
Computational Effort ◽  
Energy Storage Systems ◽  
Operational Conditions ◽  
Modeling Approaches ◽  
Thermal Energy Storage Systems

Borehole thermal energy storage (BTES) systems facilitate the subsurface seasonal storage of thermal energy on district heating scales. These systems’ performances are strongly dependent on operational conditions like temperature levels or hydraulic circuitry. Preliminary numerical system simulations improve comprehension of the storage performance and its interdependencies with other system components, but require both accurate and computationally efficient models. This study presents a toolbox for the simulation of borehole thermal energy storage systems in Modelica. The storage model is divided into a borehole heat exchanger (BHE), a local, and a global sub-model. For each sub-model, different modeling approaches can be deployed. To assess the overall performance of the model, two studies are carried out: One compares the model results to those of 3D finite element method (FEM) models to investigate the model’s validity over a large range of parameters. In a second study, the accuracies of the implemented model variants are assessed by comparing their results to monitoring data from an existing BTES system. Both studies prove the validity of the modeling approaches under investigation. Although the differences in accuracy for the compared variants are small, the proper model choice can significantly reduce the computational effort.

scholarly journals Nano-Enhanced Phase Change Materials in Latent Heat Thermal Energy Storage Systems: A Review

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3821
Author(s):  
Kassianne Tofani ◽  
Saeed Tiari
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Storage Systems ◽  
Heat Pipes ◽  
Energy Storage Systems ◽  
Thermal Energy Storage Systems

Latent heat thermal energy storage systems (LHTES) are useful for solar energy storage and many other applications, but there is an issue with phase change materials (PCMs) having low thermal conductivity. This can be enhanced with fins, metal foam, heat pipes, multiple PCMs, and nanoparticles (NPs). This paper reviews nano-enhanced PCM (NePCM) alone and with additional enhancements. Low, middle, and high temperature PCM are classified, and the achievements and limitations of works are assessed. The review is categorized based upon enhancements: solely NPs, NPs and fins, NPs and heat pipes, NPs with highly conductive porous materials, NPs and multiple PCMs, and nano-encapsulated PCMs. Both experimental and numerical methods are considered, focusing on how well NPs enhanced the system. Generally, NPs have been proven to enhance PCM, with some types more effective than others. Middle and high temperatures are lacking compared to low temperature, as well as combined enhancement studies. Al2O3, copper, and carbon are some of the most studied NP materials, and paraffin PCM is the most common by far. Some studies found NPs to be insignificant in comparison to other enhancements, but many others found them to be beneficial. This article also suggests future work for NePCM and LHTES systems.

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