Optimal Design of a Molten Salt Thermal Storage Tank for Parabolic Trough Solar Power Plants

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
R. Gabbrielli ◽  
C. Zamparelli
Keyword(s):  
Optimal Design ◽  
Molten Salt ◽  
Storage Tank ◽  
Power Plants ◽  
Storage System ◽  
Thermal Storage ◽  
Parabolic Trough ◽  
Investment Cost ◽  
Total Investment ◽  
Solar Power Plants

This paper presents an optimal design procedure for internally insulated, carbon steel, molten salt thermal storage tanks for parabolic trough solar power plants. The exact size of the vessel and insulation layers and the shape of the roof are optimized by minimizing the total investment cost of the storage system under three technical constraints: remaining within the maximum allowable values of both temperature and stress in the steel structure, and avoiding excessive cooling and consequent solidification of the molten salt during long periods of no solar input. The thermal, mechanical and economic aspects have been integrated into an iterative step-by-step optimization procedure, which is shown to be effective through application to the case study of a 600MWh thermal storage system. The optimal design turns out to be an internally insulated, carbon steel storage tank characterized by a maximum allowable height of 11m and a diameter of 22.4m. The total investment cost is about 20% lower than that of a corresponding AISI 321H stainless steel storage tank without internal protection or insulation.

Development of a Molten-Salt Thermocline Thermal Storage System for Parabolic Trough Plants

2002 ◽  
Vol 124 (2) ◽  
pp. 153-159 ◽  
Author(s):  
James E. Pacheco ◽  
Steven K. Showalter ◽  
William J. Kolb
Keyword(s):  
Molten Salt ◽  
Thermal Gradient ◽  
Power Plants ◽  
Low Cost ◽  
Storage System ◽  
Thermal Storage ◽  
Pilot Scale ◽  
Heat Transfer Fluid ◽  
Parabolic Trough ◽  
Molten Salt System

Thermal storage improves the dispatchability and marketability of parabolic trough power plants allowing them to produce electricity on demand independent of solar collection. One such thermal storage system, a thermocline, uses a single tank containing a fluid with a thermal gradient running vertically through the tank, where hotter fluid (lower density) is at the top of the tank and colder fluid is at the base of the tank. The thermal gradient separates the two temperature potentials. A low-cost filler material provides the bulk of the thermal capacitance of the thermal storage, prevents convective mixing, and reduces the amount of fluid required. In this paper, development of a thermocline system that uses molten-nitrate salt as the heat transfer fluid is described and compared to a two-tank molten salt system. Results of isothermal and thermal cycling tests on candidate materials and salt safety tests are presented as well as results from a small pilot-scale (2.3 MWh) thermocline.

Development of a Molten-Salt Thermocline Thermal Storage System for Parabolic Trough Plants

2001 ◽  
Author(s):  
James E. Pacheco ◽  
Steven K. Showalter ◽  
William J. Kolb
Keyword(s):  
Molten Salt ◽  
Thermal Gradient ◽  
Power Plants ◽  
Low Cost ◽  
Storage System ◽  
Thermal Storage ◽  
Pilot Scale ◽  
Heat Transfer Fluid ◽  
Parabolic Trough ◽  
Molten Salt System

Abstract Thermal storage improves the dispatchability and marketability of parabolic trough power plants allowing them to produce electricity on demand independent of solar collection. One such thermal storage system, a thermocline, uses a single tank containing a fluid with a thermal gradient running vertically through the tank, where hotter fluid (lower density) is at the top of the tank and colder fluid is at the base of the tank. The thermal gradient separates the two temperature potentials. A low-cost filler material provides the bulk of the thermal capacitance of the thermal storage, prevents convective mixing, and reduces the amount of fluid required. In this paper, development of a thermocline system that uses molten-nitrate salt as the heat transfer fluid is described and compared to a two-tank molten salt system. Results of isothermal and thermal cycling tests on candidate materials and salt safety tests are presented as well as results from a small pilot-scale (2.3 MWh) thermocline.

Optimal Design of Integrated Solar Power Plants Accounting for the Thermal Storage System and CO2 Mitigation through an Algae System

2016 ◽  
Vol 55 (41) ◽  
pp. 11003-11011 ◽  
Author(s):  
José Francisco Hernández-Martinez ◽  
Eusiel Rubio-Castro ◽  
Medardo Serna-González ◽  
Mahmoud M. El-Halwagi ◽  
José María Ponce-Ortega
Keyword(s):  
Optimal Design ◽  
Power Plants ◽  
Solar Power ◽  
Storage System ◽  
Thermal Storage ◽  
Co2 Mitigation ◽  
Solar Power Plants

scholarly journals Conceptual Study of a Thermal Storage Module for Solar Power Plants with Parabolic Trough Concentrators

10.5772/54060 ◽  
2013 ◽  
Author(s):  
Valentina A. ◽  
Carmelo E. ◽  
Giuseppe M. ◽  
Rosa Di ◽  
Fabrizio Girardi ◽  
...  
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Thermal Storage ◽  
Parabolic Trough ◽  
Solar Power Plants ◽  
Conceptual Study

Comparison of Two-Tank Indirect Thermal Storage Designs for Solar Parabolic Trough Power Plants

2009 ◽  
Author(s):  
Joseph Kopp ◽  
R. F. Boehm
Keyword(s):  
Power Generation ◽  
Molten Salt ◽  
Heat Exchangers ◽  
Power Plants ◽  
Thermal Storage ◽  
Heat Transfer Fluid ◽  
Base Case ◽  
Parabolic Trough ◽  
Trade Offs ◽  
Solar Field

The performance of a solar thermal parabolic trough plant with thermal storage is dependent upon the arrangement of the heat exchangers that ultimately transfer energy from the sun into steam. An indirect two-tank molten salt storage system that only transfers heat with the solar field heat transfer fluid is the most commercially acceptable thermal storage design. Annual electricity generation from two differing indirect two-tank molten salt storage designs and a base case with no thermal storage were modeled. Four components were characterized in a quasi-steady state analysis dependent upon key ambient and operational parameters: solar field, storage, heat exchangers, and power block. The parameters for the collector field remained constant for all models and were based on the SEGS VI plant. The results of net power generation favor storage though the design that maximizes annual output depends on whether maximum power generation or power generation during the evening peak demand hours is desired. Additionally, the economic trade offs are discussed for the three arrangements.

Assessment of Thermal Energy Storage for Parabolic Trough Solar Power Plants

Solar Energy ◽  
2004 ◽  
Author(s):  
David Kearney ◽  
Henry Price
Keyword(s):  
Energy Storage ◽  
Molten Salt ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Power Plants ◽  
Solar Power ◽  
Storage System ◽  
Parabolic Trough ◽  
Levelized Cost Of Electricity ◽  
Cost Of Electricity

Parabolic trough power plant technology is one of the most demonstrated solar power options commercially available. While trough power plants are the least expensive solar option, cost of electricity still exceeds that needed to directly compete with conventional fossil-fired large-scale central power technologies. Several evaluations have been done that identify a series of mechanisms for significant cost reduction over the next decade. One of the opportunities for improving the economics of parabolic trough plants is the development of lower cost and more efficient thermal energy storage (TES) technologies. This paper focuses on several of the TES technologies currently under development, namely: the use of an indirect molten-salt storage system, the use of molten-salt as a heat transfer fluid in the solar field and thermal energy storage system, and the development of new types of storage fluids. The assessment compares the cost and performance of these candidate thermal energy storage technologies by evaluating their impact on the levelized cost of electricity from the plant. This analysis is updated based on work conducted on these technologies during the last year.

scholarly journals Experimental Study on Temperature Distribution and Heat Losses of a Molten Salt Heat Storage Tank

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1943 ◽  
Author(s):  
Xiaoming Zhang ◽  
Yuting Wu ◽  
Chongfang Ma ◽  
Qiang Meng ◽  
Xiao Hu ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Molten Salt ◽  
Storage Tank ◽  
Power Plants ◽  
Heat Storage ◽  
Thermal Power ◽  
Thermal Storage ◽  
Heat Losses ◽  
Temperature Stratification ◽  
Maximum Temperature

Two-tank molten salt heat storage systems are considered to be the most mature thermal storage technology in solar thermal power plants. As the key part of the system, the thermal performance of molten salt tanks is of great importance. An experimental thermal storage system with a new type of molten salt as a thermal energy storage medium has been built to investigate the temperature distribution of molten salt inside the tank during the cooling process from 550 °C to 180 °C. The temperature distribution of the salt was obtained, which reveals that temperature stratification appears at the bottom of the tank within the height of 200 mm. The position, with the maximum temperature difference of 16.1 °C, is at the lower edges of the molten salt storage tank. The temperature distribution was also measured to deepen our understanding of the insulation foundation, which shows that the maximum temperature appears at the middle upper part of the foundation and decreases radially. The heat losses of the molten salt tank were calculated by the classical equation, from which it was found that the heat loss decreases from 3.65 kWh to 1.82 kWh as the temperature of the molten salt drops from 550 °C to 310 °C. The effect of temperature stratification on the heat losses of the tank’s bottom was also analyzed.

scholarly journals Energetic and exergetic analysis of Rankine cycles for solar power plants with parabolic trough and thermal storage

2016 ◽  
Vol 1 ◽  
pp. 10 ◽  
Author(s):  
Victor-Eduard Cenuşă ◽  
George Darie ◽  
Diana Tuţică ◽  
Mihaela Norişor ◽  
Florin-Niculae Alexe ◽  
...  
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Thermal Storage ◽  
Parabolic Trough ◽  
Solar Power Plants ◽  
Exergetic Analysis

Design and Analysis of Low-Cost Thermal Storage System for High Efficiency Concentrating Solar Power Plants

2016 ◽  
Author(s):  
Karthik Nithyanandam ◽  
Amey Barde ◽  
Reza Baghaei Lakeh ◽  
Richard Wirz
Keyword(s):  
High Temperatures ◽  
Power Plants ◽  
Solar Power ◽  
Storage System ◽  
Cost Effective ◽  
Thermal Storage ◽  
System Level ◽  
Complex Conjugate ◽  
Concentrating Solar Power ◽  
Solar Power Plants

The ability to efficiently and cost-effectively incorporate thermal energy storage (TES) systems is an important advantage of concentrating solar power (CSP) in comparison to other intermittent forms of renewable energy, such as wind or photovoltaics. As such, TES allows CSP plants to continue to provide electricity to the grid even at times when the resource (the sun) is not available, such as cloud transients or at night. Advanced power cycle systems with supercritical carbon dioxide (sCO2) as the working fluid provide high power conversion efficiency because of high temperatures attained, and less compression work and are being explored for integration with concentrating solar power plants. Currently, there is no cost-effective way to store energy at high temperatures (>565 degree Celsius). The present work analyzes the thermal performance of a novel, cost-effective thermal storage system based on elemental sulfur as the storage media. The analysis is based on a detailed system-level computational modeling of the complex conjugate heat transfer and fluid flow phenomena at multiple scales to provide a scientific basis for engineering, designing and optimizing the novel thermal storage system for transient operation. The validation of the computational model based on data from experiments and full-scale plant operation is also reported. Our studies have shown sulfur-based TES to be a promising candidate for high temperature CSP.

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