scholarly journals Performance of an Indirect Packed Bed Reactor for Chemical Energy Storage

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5149
Author(s):  
Tiziano Delise ◽  
Salvatore Sau ◽  
Anna Chiara Tizzoni ◽  
Annarita Spadoni ◽  
Natale Corsaro ◽  
...  
Keyword(s):  
Energy Storage ◽  
Heat Exchanger ◽  
Stokes Equations ◽  
Storage Period ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Solar Irradiation ◽  
Heat Transfer Fluid ◽  
Inlet Temperature ◽  
Symmetrical Configuration

Chemical systems for thermal energy storage are promising routes to overcome the issue of solar irradiation discontinuity, helping to improve the cost-effectiveness and dispatchability of this technology. The present work is concerned with the simulation of a configuration based on an indirect-packed bed heat exchanger, for which few experimental and modelling data are available about practical applications. Since air shows advantages both as a reactant and heat transfer fluid, the modelling was performed considering a redox oxide based system, and, for this purpose, it was considered a pelletized aluminum/manganese spinel. A symmetrical configuration was selected and the calculation was carried out considering a heat duty of 125 MWth and a storage period of 8 h. Firstly, the heat exchanger was sized considering the mass and energy balances for the discharging step, and, subsequently, air inlet temperature and mass flow were determined for the charging step. The system performances were then modelled as a function of the heat exchanger length and the charging and discharging time, by solving the relative 1D Navier-Stokes equations. Despite limitations in the global heat exchange efficiency, resulting in an oversize of the storage system, the results showed a good storage efficiency of about 0.7.

Reduction of iron–manganese oxide particles in a lab-scale packed-bed reactor for thermochemical energy storage

2020 ◽  
Vol 221 ◽  
pp. 115700 ◽  
Author(s):  
Marziyeh Hamidi ◽  
Vincent M. Wheeler ◽  
Xiang Gao ◽  
John Pye ◽  
Kylie Catchpole ◽  
...  
Keyword(s):  
Energy Storage ◽  
Manganese Oxide ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Reduction Of Iron ◽  
Oxide Particles ◽  
Iron Manganese

Dynamic Performance Analysis of Large-Scale Packed Bed Truncated Conical Thermal Energy Storage

2019 ◽  
Author(s):  
Shobhana Singh ◽  
Kim Sørensen
Keyword(s):  
Energy Storage ◽  
Large Scale ◽  
Storage System ◽  
Transient Behavior ◽  
Packed Bed ◽  
Energy Storage System ◽  
Heat Transfer Fluid ◽  
Design Parameters ◽  
Wide Range ◽  
Dynamic Performance Analysis

Abstract In the present paper, a high-temperature packed bed energy storage system of volume 175,000m3 is numerically investigated. The system is a underground packed bed of truncated conical shape, which comprises of rocks as a storage medium and air as a heat transfer fluid. A one-dimensional, two-phase model is developed to simulate the transient behavior of the storage. The developed model is used to conduct a parametric study with a wide range of design parameters to investigate the change in performance during both charging and discharging operation. Results show that the model satisfactorily predicts the dynamic behavior, and the truncated conical shaped storage with a rock diameter of 3cm, insulation thickness up to 0.6m and charging-discharging rate of 553kg/s leads to lower thermal losses and higher energy efficiencies. The paper provides useful insight into the transient performance and efficiency of a large-scale packed bed energy storage system within the range of parameters investigated.

Numerical Study of Thermochemical Storage Using Ca(OH)2/CaO: High Temperature Applications

2016 ◽  
Author(s):  
Qasim A. Ranjha ◽  
Nasser Vahedi ◽  
Alparslan Oztekin
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Numerical Study ◽  
Storage System ◽  
Packed Bed ◽  
Heat Transfer Fluid ◽  
Operational Parameters ◽  
Storage And Retrieval

Thermal energy storage by reversible gas-solid reaction has been selected as a thermochemical energy storage system. Simulations are conducted to investigate the dehydration of Ca(OH)2 and the hydration of CaO for thermal energy storage and retrieval, respectively. The rectangular packed bed is heated indirectly by air used as a heat transfer fluid (HTF) while the steam is transferred through the upper side of the bed. Transient mass transport and heat transfer equations coupled with chemical kinetics equations for a two dimensional geometry have been solved using finite element method. Numerical results have been validated by comparing against results of previous measurements and simulations. The effect of geometrical and operational parameters including the material properties on overall storage and retrieval process has been investigated. The co-current and counter-current flow arrangements for steam and heat transfer fluid have been considered.

Investigation of a High-Temperature Packed-Bed Sensible Heat Thermal Energy Storage System With Large-Sized Elements

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Sarada Kuravi ◽  
Jamie Trahan ◽  
Yogi Goswami ◽  
Chand Jotshi ◽  
Elias Stefanakos ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Energy Storage ◽  
Flow Rate ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Packed Bed ◽  
Inlet Temperature ◽  
Prototype System ◽  
Sensible Heat

A high-temperature, sensible heat thermal energy storage (TES) system is designed for use in a central receiver concentrating solar power plant. Air is used as the heat transfer fluid and solid bricks made out of a high storage density material are used for storage. Experiments were performed using a laboratory-scale TES prototype system, and the results are presented. The air inlet temperature was varied between 300 °C to 600 °C, and the flow rate was varied from 50 cubic feet per minute (CFM) to 90 CFM. It was found that the charging time decreases with increase in mass flow rate. A 1D packed-bed model was used to simulate the thermal performance of the system and was validated with the experimental results. Unsteady 1D energy conservation equations were formulated for combined convection and conduction heat transfer and solved numerically for charging/discharging cycles. Appropriate heat transfer and pressure drop correlations from prior literature were identified. A parametric study was done by varying the bed dimensions, fluid flow rate, particle diameter, and porosity to evaluate the charging/discharging characteristics, overall thermal efficiency, and capacity ratio of the system.

scholarly journals Experimental Investigation of PCM Spheres in Thermal Energy Storage System

2013 ◽  
Vol 367 ◽  
pp. 228-233 ◽  
Author(s):  
N.A.M. Amin ◽  
Azizul Mohamad ◽  
M.S. Abdul Majid ◽  
Mohd Afendi ◽  
Frank Bruno ◽  
...  
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Packed Bed ◽  
Energy Storage System ◽  
Heat Transfer Fluid ◽  
Experimental Result ◽  
Small Scale ◽  
Storage Unit

This paper presents the experimental result of a small scale packed bed of random spheres with encapsulated PCM being charged and discharged. A vapor compression refrigerator and heated room with fan heater were used to supply constant heat transfer fluid at a minimum temperature of -28°C for charging and 16°C for discharging. Even though the temperature differences were not fixed in the experiments, the performance of the thermal energy storage is depicted in the form of effectiveness values. Different results were obtained for charging and discharging the thermal storage unit. The differences are expected to come from natural convection and super cooling. The super cooling during the charging process was as high as 6°C.

Optimization of a Phase Change Thermal Storage Unit

2010 ◽  
Author(s):  
Monica F. Bonadies ◽  
Mark Ricklick ◽  
J. S. Kapat
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Energy Storage ◽  
Heat Exchanger ◽  
Phase Change ◽  
Thermal Energy ◽  
Paraffin Wax ◽  
Heat Transfer Fluid ◽  
Storage Unit ◽  
Domestic Use

When collecting the energy of the sun for domestic use, several options exist, one being the use of evacuated tube collectors with internal heat pipes. This study proposes a system integrating these collectors with a storage unit using the phase change of paraffin wax to store energy. The storage unit makes use of a finned heat exchanger, with paraffin wax on the shell side and glycol on the tube side as the heat transfer fluid. The heat exchanger is embedded within the storage paraffin wax with a volume of 2 ft3. The heat exchanger also includes a separate loop for water to flow through and receive thermal energy from the melted wax. Although the wax has the benefit of being inexpensive and nontoxic, it has the problem of low thermal conductivity. Therefore, the heat exchanger has large copper fins brazed to it to extend areas of high thermal conductivity into the wax reservoir. The unit used in this study contains 14 fins. The use of fins will help to speed up the melting of the wax while solar energy is collected, since there is more heat transfer area. When most of the wax is melted, heat can be exchanged to water for domestic use. To determine the benefit of the fins, wax and working fluid temperature data will be taken from a constructed thermal energy storage unit, and then it is used to verify a finite-difference analytical model of the thermal operating characteristics. The maximum operating temperature of the glycol/water mix heat transfer fluid was approximately 65° C when the fluid flowed at 1 gallon per minute. The storage unit was able to store melted wax overnight with a 2–3°C temperature drop with the ambient temperature approximately at 30°C. City water at approximately 3 gpm was used to test the freezing side. The one dimensional model proved useful in predicting the heat storage mode of the system but had some error in predicting the heat release mode of the unit. The model also points to the fact that there are several considerations to be taken when simulating phase change energy storage processes.

scholarly journals Modeling and Design of a Multi-Tubular Packed-Bed Reactor for Methanol Steam Reforming over a Cu/ZnO/Al2O3 Catalyst

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 610 ◽  
Author(s):  
Jimin Zhu ◽  
Samuel Simon Araya ◽  
Xiaoti Cui ◽  
Simon Lennart Sahlin ◽  
Søren Knudsen Kær
Keyword(s):  
Steam Reforming ◽  
Packed Bed ◽  
Methanol Conversion ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Inlet Temperature ◽  
Methanol Steam Reforming ◽  
Shell Side ◽  
Co Concentration ◽  
The Impact

Methanol as a hydrogen carrier can be reformed with steam over Cu/ZnO/Al2O3 catalysts. In this paper a comprehensive pseudo-homogenous model of a multi-tubular packed-bed reformer has been developed to investigate the impact of operating conditions and geometric parameters on its performance. A kinetic Langmuir-Hinshelwood model of the methanol steam reforming process was proposed. In addition to the kinetic model, the pressure drop and the mass and heat transfer phenomena along the reactor were taken into account. This model was verified by a dynamic model in the platform of ASPEN. The diffusion effect inside catalyst particles was also estimated and accounted for by the effectiveness factor. The simulation results showed axial temperature profiles in both tube and shell side with different operating conditions. Moreover, the lower flow rate of liquid fuel and higher inlet temperature of thermal air led to a lower concentration of residual methanol, but also a higher concentration of generated CO from the reformer exit. The choices of operating conditions were limited to ensure a tolerable concentration of methanol and CO in H2-rich gas for feeding into a high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) stack. With fixed catalyst load, the increase of tube number and decrease of tube diameter improved the methanol conversion, but also increased the CO concentration in reformed gas. In addition, increasing the number of baffle plates in the shell side increased the methanol conversion and the CO concentration.

Transient discrete-granule packed-bed reactor model for thermochemical energy storage

2014 ◽  
Vol 117 ◽  
pp. 465-478 ◽  
Author(s):  
Stefan Ströhle ◽  
Andreas Haselbacher ◽  
Zoran R. Jovanovic ◽  
Aldo Steinfeld
Keyword(s):  
Energy Storage ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Reactor Model
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