Computational Modeling of Thermal Energy Storage in Rock Beds

2010 ◽  
Author(s):  
Tihomir G. Sivov ◽  
Raul Palacios-Gamez ◽  
B. Rabi Baliga
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Supply And Demand ◽  
Evaluation Criteria ◽  
Cost Effective ◽  
Working Fluid ◽  
Test Problems ◽  
Rock Bed ◽  
Building Engineering

Thermal energy storage (TES) systems are commonly employed for enhancing the efficiency of commercial and residential heating and cooling systems, by matching thermal energy supply and demand during summer-winter, day-night, and peak-off-peak periods. TES in these systems is usually achieved by changing the temperature of materials (sensible systems) and/or inducing solid-liquid phase change (latent heat systems). Such systems are also categorized as seasonal (long-term) and diurnal (short-term). In this work, the focus is on sensible diurnal TES systems consisting of rock beds, with air as the working fluid. They are relatively simple, easy to construct, inexpensive, and quite effective for many solar energy and building engineering applications. Numerous publications on rock-bed TES systems are available, but there is an urgent need for efficient computational methods for designing and optimizing them. The contributions of this work are the following: proposal of cost-effective mathematical models of fluid flow and heat transfer in rock beds; adaptation of a finite volume method (FVM) for the solution of this model; applications of this FVM to two test problems (with analytical solutions) and one demonstration problem; proposal of suitable thermofluid performance evaluation criteria for the rock-bed TES systems of interest; and presentation and discussions of the results.

scholarly journals Thermal energy storage (TES) technology for active and passive cooling in buildings: A Review

2018 ◽  
Vol 225 ◽  
pp. 03022
Author(s):  
Nursyazwani Abdul Aziz ◽  
Nasrul Amri Mohd Amin ◽  
Mohd Shukry Abd Majid ◽  
Izzudin Zaman
Keyword(s):  
Energy Storage ◽  
Energy Management ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Energy Demand ◽  
Supply And Demand ◽  
Storage System ◽  
Passive Cooling ◽  
Building Sector ◽  
Advantages And Disadvantages

Thermal energy storage (TES) system is one of the outstanding technologies available contributes for achieving sustainable energy demand. The energy storage system has been proven capable of narrowing down the energy mismatch between energy supply and demand. The thermal energy storage (TES) - buildings integration is expected to minimize the energy demand shortage and also offers for better energy management in building sector. This paper presents a state of art of the active and passive TES technologies integrated in the building sector. The integration method, advantages and disadvantages of both techniques were discussed. The TES for low energy building is inevitably needed. This study prescribes that the integration of TES system for both active and passive cooling techniques are proven to be beneficial towards a better energy management in buildings.

Designing a novel solar-assisted heat pump system with modification of a thermal energy storage unit

2019 ◽  
Vol 233 (5) ◽  
pp. 588-603 ◽  
Author(s):  
Mustafa Aktaş ◽  
Meltem Koşan ◽  
Erhan Arslan ◽  
Azim Doğuş Tuncer
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Collector ◽  
Working Fluid ◽  
Storage Unit ◽  
Heating Systems ◽  
Energy Storage Unit

The integrated usage of solar energy systems, heat pump applications, and thermal energy storage units is an effective way for heating systems due to their sustainability and stability in operations. In this study, a novel direct solar-assisted heat pump with thermal energy system has been designed which uses the solar collector as the evaporator of the heat pump. Besides, two-dimensional transient numeric analyses have been conducted for the thermal energy storage unit using the ANSYS Fluent 16.2 commercial software package. With this direct system, the heat required for heating systems is supplied from the condenser with the heat received from the solar collector of the working fluid. For an effective and high performance system, the solar collector is designed as a double-pass which provided superheating of the working fluid. It is aimed to store the surplus energy from the solar energy in the thermal energy storage unit and to operate the system continuously and efficiently in both sunny and overcast weather conditions. Furthermore, the system has been analyzed theoretically and the results show that coefficient of performance may improve. As a result, this newly designed system can be successfully applied for thermal applications.

scholarly journals Development and Analysis of a Multi-Node Dynamic Model for the Simulation of Stratified Thermal Energy Storage

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4275 ◽  
Author(s):  
Nora Cadau ◽  
Andrea De Lorenzi ◽  
Agostino Gambarotta ◽  
Mirko Morini ◽  
Michele Rossi
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Supply And Demand ◽  
District Heating ◽  
Energy Systems ◽  
High Flow ◽  
Market Penetration ◽  
Flow Rates ◽  
Smart Energy Systems

To overcome non-programmability issues that limit the market penetration of renewable energies, the use of thermal energy storage has become more and more significant in several applications where there is a need for decoupling between energy supply and demand. The aim of this paper is to present a multi-node physics-based model for the simulation of stratified thermal energy storage, which allows the required level of detail in temperature vertical distribution to be varied simply by choosing the number of nodes and their relative dimensions. Thanks to the chosen causality structure, this model can be implemented into a library of components for the dynamic simulation of smart energy systems. Hence, unlike most of the solutions proposed in the literature, thermal energy storage can be considered not only as a stand-alone component, but also as an important part of a more complex system. Moreover, the model behavior has been analyzed with reference to the experimental results from the literature. The results make it possible to conclude that the model is able to accurately predict the temperature distribution within a stratified storage tank typically used in a district heating network with limitations when dealing with small storage volumes and high flow rates.

Energy storage analysis of CO2 in MOF-74 and UIO-66 nanoparticles: A molecular simulation study

2019 ◽  
Vol 33 (18) ◽  
pp. 1950196 ◽  
Author(s):  
Qiang Wang ◽  
Shengli Tang
Keyword(s):  
Energy Storage ◽  
Adsorption Capacity ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Working Fluid ◽  
Thermodynamic Cycles ◽  
Different Temperatures ◽  
Energy Storage Properties ◽  
Metal Organic ◽  
Adsorption Of Co

Adding porous nanoparticles into fluid can modify the energy storage properties of working fluid in the thermodynamic cycles. The adsorption capacity and thermal energy storage of CO2 in MOF-74 and UIO-66 at different temperatures and pressures are investigated in this paper via molecular simulations. The results denote that the adsorption of CO2 in the two studied metal organic frameworks (MOFs) differ from each other due to the different structures. The adsorption capacity of CO2 in MOF-74 is larger than that in UIO-66. However, the desorption heat of CO2 in MOF-74 is lower than that in UIO-66. Also, UIO-66 impacts more than MOF-74 on the thermal energy storage property of CO2.

Investigation of Thermal Properties in Nanofluids for Thermal Energy Storage Applications

2013 ◽  
Author(s):  
Aitor Zabalegui ◽  
Bernadette Tong ◽  
Hohyun Lee
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Energy Storage ◽  
Latent Heat ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Working Fluid ◽  
Traditional Theory ◽  
Energy Storage Applications ◽  
Particle Addition

Phase change materials (PCMs) are promising for thermal energy storage applications, but low thermal conductivity limits their heat exchange rate with a working fluid. The nanofluid approach has been established as a method of thermal conductivity enhancement, but particle addition may have an adverse effect on specific energy storage capacity. Latent heat reduction beyond traditional theory has been observed experimentally for carbon nanotubes dispersed in paraffin wax. Nanofluid latent heat and effective thermal conductivity were analyzed to investigate the effects of particle addition on thermal properties affecting PCM energy storage performance. It is shown that particle diameter significantly impacts nanofluid latent heat, with smaller particles generating greater degrees of reduction, but has a negligible effect on thermal conductivity. A method to approximate nanofluid latent heat of fusion is presented, considering the diameter-dependent reduction observed.

Development and Design Prototype 300 kW-Thermal High-Temperature Particle Heating Concentrator Solar Power System Utilizing Thermal Energy Storage

2014 ◽  
Author(s):  
Matthew Golob ◽  
Sheldon Jeter ◽  
Said I. Abdel-Khalik ◽  
Dennis Sadowski ◽  
Hany Al-Ansary ◽  
...  
Keyword(s):  
High Temperature ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Supply ◽  
Power Conversion ◽  
Cost Effective ◽  
Prototype System ◽  
Solar Heat ◽  
Particle Heating

The advantages of high temperature central receiver particle heating solar heat supply systems in concentrator solar power (CSP) have been recognized in recent years. The use of particulate as the collection medium provides two critical advantages: (1) Ordinary particulate minerals and products will allow higher collection temperatures approaching 1000°C compared with conventional molten salts, which are limited to around 650°C, and (2) the low cost high temperature particulate material can also be used as the storage medium in a highly cost effective thermal energy storage (TES) system. The high operating temperature allows use of high efficiency power conversion systems such as supercritical steam in a vapor power cycle or supercritical carbon dioxide in a Brayton cycle. Alternatively, a lower cost gas turbine can be used for the power conversion system. High conversion efficiency combined with inexpensive TES will yield a highly cost effective CSP system. The 300 kW-th prototype is being constructed as a solar heat supply system only, deferring the power conversion system for later demonstration in a larger integrated CSP system. This paper describes the general design and development efforts leading to construction of the 300 kW prototype system located in the Riyadh Techno Valley development near King Saud University in Riyadh, Saudi Arabia, which is the first sizeable solar heat supply system purposely designed, and constructed as a particle heating system. An important component in a particle heating system is the particle heating receiver (PHR), which should be durable and efficient while remaining cost-effective. A critical enabling technology of the PHR being implemented for this project was invented by researchers on our team. In our version of the PHR, the particulate flows downwards through a porous or mesh structure where the concentrated solar energy is absorbed. The porous structure will reduce the speed of the falling particulate material allowing a large temperature rise on a single pass. The new design will also increase the absorption of solar energy and mitigate convective heat loss and particle loss. Other innovative aspects of this design include low cost thermal energy storage bins and a cost effective particle to working fluid heat exchanger. Certain features of these design elements are subjects of ongoing patent applications. Nevertheless, the overall design and the development process of the prototype system is presented in this paper.

scholarly journals Addressing Industrial Waste Heat Supply Variability With Organic Rankine Cycle Systems Incorporating Thermal Energy Storage

2021 ◽  
Author(s):  
Bipul Krishna Saha ◽  
Basab Chakraborty ◽  
Rohan Dutta
Keyword(s):  
Power Generation ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Power Plants ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Low Grade

Abstract Industrial low-grade waste heat is lost, wasted and deposited in the atmosphere and is not put to any practical use. Different technologies are available to enable waste heat recovery, which can enhance system energy efficiency and reduce total energy consumption. Power plants are energy-intensive plants with low-grade waste heat. In the case of such plants, recovery of low-grade waste heat is gaining considerable interest. However, in such plants, power generation often varies based on market demand. Such variations may adversely influence any recovery system's performance and the economy, including the Organic Rankine Cycle (ORC). ORC technologies coupled with Cryogenic Energy Storage (CES) may be used for power generation by utilizing the waste heat from such power plants. The heat of compression in a CES may be stored in thermal energy storage systems and utilized in ORC or Regenerative ORC (RORC) for power generation during the system's discharge cycle. This may compensate for the variation of the waste heat from the power plant, and thereby, the ORC system may always work under-designed capacity. This paper presents the thermo-economic analysis of such an ORC system. In the analysis, a steady-state simulation of the ORC system has been developed in a commercial process simulator after validating the results with experimental data for a typical coke-oven plant. Forty-nine different working fluids were evaluated for power generation parameters, first law efficiencies, purchase equipment cost, and fixed investment payback period to identify the best working fluid.

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