Development and Performance Evaluation of High Temperature Concrete for Thermal Energy Storage for Solar Power Generation

2011 ◽  
Author(s):  
Emerson E. John ◽  
W. Micah Hale ◽  
R. Panneer Selvam ◽  
Bradley Brown
Keyword(s):  
Energy Storage ◽  
Molten Salt ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Silica Sand ◽  
Root Cause ◽  
Thermal Ratcheting ◽  
And Performance

This paper proposes concrete bricks as the main energy storage medium to replace aggregates in the thermocline thermal energy storage system. By developing a feasible concrete mixture, the root cause of thermal ratcheting which is the settlement of the aggregates is immediately eliminated. Fourteen concrete mixtures were submerged in molten salt at 585°C for 500 hours and were also subjected to 30 thermal cycles from 300 to 600°C in a heating furnace. The results show that 5 of the 14 mixtures exhibited adequate mechanical properties after being subjected to the thermal cycling testing regimen. All mixtures exhibited an increase in compressive strength after 500 hours of exposure in molten salt at 585°C. This illustrates that concrete as an alternative to the use of quartzite rock and silica sand is feasible.

Dynamic simulation of two-tank indirect thermal energy storage system with molten salt

2017 ◽  
Vol 113 ◽  
pp. 1311-1319 ◽  
Author(s):  
Xiaolei Li ◽  
Ershu Xu ◽  
Shuang Song ◽  
Xiangyan Wang ◽  
Guofeng Yuan
Keyword(s):  
Energy Storage ◽  
Molten Salt ◽  
Dynamic Simulation ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Thermal Energy Storage System

Computational Analysis of a Pipe Flow Distributor for a Thermocline Based Thermal Energy Storage System

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Samia Afrin ◽  
Vinod Kumar ◽  
Desikan Bharathan ◽  
Greg C. Glatzmaier ◽  
Zhiwen Ma
Keyword(s):  
Energy Storage ◽  
Molten Salt ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Computational Analysis ◽  
Storage System ◽  
Flow Distribution ◽  
Energy Storage System ◽  
Heat Transfer Fluid ◽  
Case Scenario

The overall efficiency of a concentrating solar power (CSP) plant depends on the effectiveness of thermal energy storage (TES) system (Kearney and Herrmann, 2002, “Assessment of a Molten Salt Heat Transfer Fluid,” ASME). A single tank TES system consists of a thermocline region which produces the temperature gradient between hot and cold storage fluid by density difference (Energy Efficiency and Renewable Energy, http://www.eere.energy.gov/basics/renewable_energy/thermal_storage.html). Preservation of this thermocline region in the tank during charging and discharging cycles depends on the uniformity of the velocity profile at any horizontal plane. Our objective is to maximize the uniformity of the velocity distribution using a pipe-network distributor by varying the number of holes, distance between the holes, position of the holes and number of distributor pipes. For simplicity, we consider that the diameter of the inlet, main pipe, the distributor pipes and the height and the width of the tank are constant. We use Hitec® molten salt as the storage medium and the commercial software Gambit 2.4.6 and Fluent 6.3 for the computational analysis. We analyze the standard deviation in the velocity field and compare the deviations at different positions of the tank height for different configurations. Since the distance of the holes from the inlet and their respective arrangements affects the flow distribution throughout the tank; we investigate the impacts of rearranging the holes position on flow distribution. Impact of the number of holes and distributor pipes are also analyzed. We analyze our findings to determine a configuration for the best case scenario.

A 5 kWht Lab-Scale Demonstration of a Novel Thermal Energy Storage Concept With Supercritical Fluids

2013 ◽  
Author(s):  
Gani B. Ganapathi ◽  
Daniel Berisford ◽  
Benjamin Furst ◽  
David Bame ◽  
Michael Pauken ◽  
...  
Keyword(s):  
High Temperature ◽  
Energy Storage ◽  
Molten Salt ◽  
Supercritical Fluid ◽  
Supercritical Fluids ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Storage Tank ◽  
Storage System ◽  
Energy Storage System

An alternate to the two-tank molten salt thermal energy storage system using supercritical fluids is presented. This technology can enhance the production of electrical power generation and high temperature technologies for commercial use by lowering the cost of energy storage in comparison to current state-of-the-art molten salt energy storage systems. The volumetric energy density of a single-tank supercritical fluid energy storage system is significantly higher than a two-tank molten salt energy storage system due to the high compressibilities in the supercritical state. As a result, the single-tank energy storage system design can lead to almost a factor of ten decrease in fluid costs. This paper presents results from a test performed on a 5 kWht storage tank with a naphthalene energy storage fluid as part of a small preliminary demonstration of the concept of supercritical thermal energy storage. Thermal energy is stored within naphthalene filled tubes designed to handle the temperature (500 °C) and pressure (6.9 MPa or 1000 psia) of the supercritical fluid state. The tubes are enclosed within an insulated shell heat exchanger which serves as the thermal energy storage tank. The storage tank is thermally charged by flowing air at >500 °C over the storage tube bank. Discharging the tank can provide energy to a Rankine cycle (or any other thermodynamic process) over a temperature range from 480 °C to 290 °C. Tests were performed over three stages, starting with a low temperature (200 °C) shake-out test and progressing to a high temperature single cycle test cycling between room temperature and 480 °C and concluding a two-cycle test cycling between 290 °C and 480 °C. The test results indicate a successful demonstration of high energy storage using supercritical fluids.

Techno-Economic Analysis of Concentrating Solar Power Plants With Integrated Latent Thermal Storage Systems

2013 ◽  
Author(s):  
K. Nithyanandam ◽  
R. Pitchumani
Keyword(s):  
Energy Storage ◽  
Molten Salt ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Power ◽  
Storage System ◽  
Design Parameters ◽  
Exergetic Efficiency ◽  
Concentrating Solar Power ◽  
And Performance

Integrating a thermal energy storage (TES) in a concentrating solar power (CSP) plant allows for continuous operation even during times when solar radiation is not available, thus providing a reliable output to the grid. In the present study, the cost and performance models of an encapsulated phase change material thermocline storage system are integrated with a CSP power tower system model to investigate its dynamic performance. The influence of design parameters of the storage system is studied for different solar multiples of the plant to establish design envelopes that satisfy the U.S. Department of Energy SunShot Initiative requirements, which include a round-trip exergetic efficiency greater than 95% and storage cost less than $15/kWht for a minimum discharge period of 6 hours. From the design windows, optimum designs of the storage system based on minimum LCOE, maximum exergetic efficiency, and maximum capacity factor are reported and compared with the results of two-tank molten salt storage system. Overall, this study presents the first effort to construct a latent thermal energy storage (LTES)-integrated CSP plant model, that can help decision makers in assessing the impact, cost and performance of a latent thermocline energy storage system on power generation from molten salt power tower CSP plant.

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