CHARACTERISTICS OF MOLTEN SALTS AND RECOMMENDATIONS FOR USE IN SOLAR POWER STATIONS

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Samaan G. Ladkany ◽  
William G. Culbreth ◽  
Nathan Loyd
Keyword(s):  
Molten Salt ◽  
Molten Salts ◽  
Solar Power ◽  
Weather Conditions ◽  
Thermal Capacity ◽  
Naval Research ◽  
Power Stations ◽  
Office Of Naval Research ◽  
The Us ◽  
Efficient Type

Molten salts (MS) in the 580°C range could be used to store excess energy from solar power stations and possibly from nuclear or coal. The energy can be stored up to a week in large containers at elevated temperature to generate eight hours of electricity to be used at night or during peak demand hours. This helps to reduce the fluctuation experienced at thermal solar power stations due to weather conditions. Our research supported by Office of Naval Research (ONR), presents a survey of salts to be used in molten salt technology. The physical characteristics of these salts such as density, melting temperature, viscosity, electric conductivity, surface tension, thermal capacity and cost are discussed. Cost is extremely important given the large volumes of salt required for energy storage at a commercial power station. Formulas are presented showing the amount of salt needed per required megawatts of stored energy depending on the type of salt. The estimated cost and the size of tanks required and the operating temperatures are presented. Recommendations are made regarding the most efficient type of molten salt to use. Commercial thermal solar power stations have been constructed in the US and overseas mainly in Spain for which molten salt is being considered. A field of flat mirrors together with collection towers are used in some designs and parabolic troughs used in others.

LATEST WORLDWIDE DEVELOPMENTS IN MOLTEN SALT TECHNOLOGY AND APPLICATIONS

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Nathan Loyd ◽  
Samaan G. Ladkany
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Molten Salt ◽  
Molten Salts ◽  
Solar Power ◽  
Weather Conditions ◽  
The United States ◽  
Naval Research ◽  
Power Stations ◽  
Technological Developments

Molten salt (MS) storage systems in the 565°C range can store green solar energy from thermal solar power station, such as the Crescent Dunes solar plant in Nevada. Large containers can be used to store energy and generate electricity for eight hours or more to be used at night or during peak demand hours, depending on the container size. Energy storage can reduce the fluctuation due to weather conditions experienced at thermal solar power stations because stable diurnal energy supply is made available by MS energy storage. Supported by the Office of Naval Research (ONR), the research presented discusses the recent technological developments associated with the use of molten salts for energy storage. In addition to their use for storing excess solar energy, molten salts are starting to be used in nuclear or hybrid power production. One particular aspect of interest is the focus using higher temperature salts to provide even more energy storage than conventional molten salts. One such salt, SaltStream700, allows for the use of molten salts at temperatures of 700°C. A summary of worldwide examples of concentrating solar power (CSP) plants is presented. Commercial solar power stations have been constructed in the United States and overseas, particularly in Spain, with molten salt being considered for use in these facilities.

scholarly journals ALTERNATIVE DESIGNS OF MOLTEN SALT STORAGE SHELLS FOR USE IN SOLAR ENERGY STORAGE

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Nathan Loyd ◽  
Samaan Ladkany
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Molten Salt ◽  
Solar Power ◽  
Weather Conditions ◽  
Heat Transfer Analysis ◽  
Naval Research ◽  
Cylindrical Tank ◽  
Office Of Naval Research ◽  
Tank Design

Molten salt (MS) storage systems in the 565°C range can store green solar energy from thermal solar power station, such as the Crescent Dunes solar plant in Nevada. Large containers can be used to store energy and generate electricity for eight hours or more to be used at night or during peak demand hours, depending on the container size. Energy storage can reduce the fluctuation due to weather conditions experienced at thermal solar power stations because stable diurnal energy supply is made available by MS energy storage. Supported by the Office of Naval Research (ONR), the research presented discusses the considerations for designing molten salt storage tanks. An alternate molten salt storage cylindrical tank design layout is presented, including an improved roof design concept. A preliminary heat transfer analysis is presented and discussed for the alternate cylindrical tank design. This preliminary analysis was used to determine the thickness of insulating material in and around the cylindrical tank to reduce heat flux. These insulating materials include the use of firebrick and ceramic insulation to complement the structural carbon steel and the stainless steel that is used for corrosion resistance. This paper also introduces the alternate designs of a semi-buried spherical tank and drop shell tank that can be used storing molten salts.

DESIGN OF MOLTEN SALT SHELLS FOR USE IN ENERGY STORAGE AT SOLAR POWER PLANTS

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Samaan G. Ladkany ◽  
William G. Culbreth ◽  
Nathan Loyd
Keyword(s):  
Stainless Steel ◽  
Molten Salt ◽  
Molten Salts ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Solar Power ◽  
Naval Research ◽  
Solar Thermal Energy ◽  
Steel Columns ◽  
Solar Power Plants

Design of a steel tank for the storage of excess energy from thermal solar power plants using molten salts (MS) at 580°C is presented. Energy can be stored up to a week in large containers to generate eight hours of electricity for use at night or to reduce weather related fluctuation at solar thermal energy plants. Our research supported by Office of Naval Research (ONR) presents a detailed design of a cylindrical shell for the storage of high temperature molten salts. The storage shell consists of an inner stainless steel layer designed to resist corrosion and an external steel structural layer to contain the large pressures resulting from the molten salt. The cylindrical tank is 54 feet (16.459 meters) high and has an 80 feet (48.768 meters) diameter, with the salt level at a height of 42 feet (12.802 meters). Given the heat of the molten salt and the size of the tank, the design includes a flat shell cover supported on stainless steel columns and a semispherical utility access dome at the center. Considerations are made for the reduction of strength of steel at elevated temperatures. Layers of external insulation materials are used to reduce heat loss in the storage shell. The design presents a posttensioned concrete foundation analysis for the storage tank, which sits on a layer of sand to allow for thermal expansion.

scholarly journals Concentrated Solar Power Plants with Molten Salt Storage: Economic Aspects and Perspectives in the European Union

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Andrzej Bielecki ◽  
Sebastian Ernst ◽  
Wioletta Skrodzka ◽  
Igor Wojnicki
Keyword(s):  
Molten Salt ◽  
Molten Salts ◽  
Power Plants ◽  
Solar Power ◽  
Economic Aspects ◽  
The European Union ◽  
Concentrated Solar Power ◽  
Eu Legislation ◽  
Solar Power Plants ◽  
Concentrated Solar Power Plants

Concentrated solar power plants belong to the category of clean sources of renewable energy. The paper discusses the possibilities for the use of molten salts as storage in modern CSP plants. Besides increasing efficiency, it may also shift their area of application: thanks to increased controllability, they may now be used not only to cover baseload but also as more agile, dispatchable generators. Both technological and economic aspects are presented, with focus on the European energy sector and EU legislation. General characteristics for CSP plants, especially with molten salt storage, are discussed. Perspectives for their development, first of all in economic aspects, are considered.

Experimental Investigation of Molten Salt Nanofluid for Solar Thermal Energy Application

2011 ◽  
Author(s):  
Donghyun Shin ◽  
Debjyoti Banerjee
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Molten Salt ◽  
Specific Heat Capacity ◽  
Thermal Energy ◽  
Molten Salts ◽  
Solar Power ◽  
Solar Thermal ◽  
Wide Range

The overall efficiency of a Concentrated Solar Power (CSP) system is critically dependent on the thermo-physical properties of the Thermal Energy Storage (TES) components and the Heat Transfer Fluid (HTF). Higher operating temperatures in CSP result in enhanced thermal efficiency of the thermodynamic cycles that are used in harnessing solar energy (e.g., using Rankine cycle or Stirling cycle). Particlularly, high specific heat capacity (Cp) and high thermal conductivity (k) of the HTF and TES materials enable reduction in the size and overall cost of solar power systems. However, only a limited number of materials are compatible for the high operating temperature requirements (exceeding 400°C) envisioned for the next generation of CSP systems. Molten salts have a wide range of melting point (200°C∼500°C) and are thermally stable up to 700°C. However, thermal property values of the molten salts are typically quite low (Cp is typically less than ∼2J/g-K and k is typically less than ∼1 W/m-K). To obviate these issues the molten salts can be doped with nanoparticles — resulting in the synthesis / formation of nanomaterials (nanocomposites and nanofluids). Nanofluids are colloidal suspensions formed by doping with minute concentration of nanoparticles. Nanofluids were reported for anomalous enhancement in their thermal conductivity values. In this study, molten salt-based nanofluids were synthesized by liquid solution method. A differential scanning calorimeter (DSC) was used to measure the specific heat capacity values of the proposed nanofluids. The observed enhancement in specific heat is then compared with predictions from conventional thermodynamic models (e.g. thermal equilibrium model or “simple mixing rule”). Transmission Electron Microscopy (TEM) is used to verify that minimal aggregation of nanoparticles occurred before and after the thermocycling experiments. Thermocycling experiments were conducted for repeated measurements of the specific heat capacity by using multiple freeze-thaw cycles of the nanofluids/ nano-composites, respectively. This study demonstrates the feasibility for using novel nanomaterials as high temperature nanofluids for applications in enhancing the operational efficiencies as well as reducing the cost of electricity produced in solar thermal systems utilizing CSP in combination with TES.

scholarly journals Little Big El-Mo

2001 ◽  
Vol 123 (10) ◽  
pp. 52-55 ◽  
Author(s):  
Paul Sharke
Keyword(s):  
High Temperature ◽  
Assembly Line ◽  
Naval Research ◽  
New Techniques ◽  
Ship Propulsion ◽  
High Temperature Superconducting ◽  
Superconducting Motor ◽  
Office Of Naval Research ◽  
The Us ◽  
The Many

This article reviews the arrival of commercial high-temperature superconducting (HTS) motors in the market. American Superconductor is concentrating its motor efforts on ship propulsion. The company has a contract with the US Navy’s Office of Naval Research to design and develop propulsion motors up to 33,500 hp. The big advantage of a superconducting motor aboard a ship is its small size, which frees up valuable square footage in the hull for the many other components needed in battle. Because superconducting motors will be about half the weight of their conventional counterparts, the efficiencies an assembly line brings to manufacturing suddenly open for many of them. Lighter, smaller designs also will translate to time saved in testing. Many of the technologies used in the 200-hp machine transferred to the 1000-hp unit, and many new techniques developed as well.

Risk-based Simulation Models for the Construction of the Mobile Offshore Base

2000 ◽  
Vol 16 (04) ◽  
pp. 241-252
Author(s):  
William J. Bender ◽  
Andrew N. Blair ◽  
Bilal M. Ayyub
Keyword(s):  
Simulation Models ◽  
Construction Cost ◽  
Simulation Software ◽  
Naval Research ◽  
Floating Structure ◽  
Feasibility Assessment ◽  
Office Of Naval Research ◽  
The Us ◽  
Resource Requirements ◽  
Mobile Offshore Base

Several very large ocean structures have been proposed as part of the Office of Naval Research feasibility study of a Mobile Offshore Base (MOB). The MOB platform nominally is about 1500 m (l mile) by 129 m (400 ft), which is unprecedented in size and operations compared to any floating structure to date. The objective of this study was to provide a risk-informed construction feasibility assessment for five proposed MOB concepts and quantify their construction cost and schedule. The risks associated with the concepts' cost and schedule were established by comparing resource requirements to build a MOB with the US industrial capacity. These risks were then modeled and simulated using commercial simulation software to provide cost and schedule estimates that accounted for uncertainty and risks. The scope of this study was limited to the construction of the hull.

scholarly journals Excessive Acceleration Criterion: Application to Naval Ships

2019 ◽  
Vol 7 (12) ◽  
pp. 431 ◽  
Author(s):  
Guido Boccadamo ◽  
Gennaro Rosano
Keyword(s):  
Failure Modes ◽  
Vertical Direction ◽  
Naval Research ◽  
Stability Criteria ◽  
Office Of Naval Research ◽  
Intact Stability ◽  
The Us ◽  
Ship Roll ◽  
Hull Forms ◽  
Level 2

In this paper, the application of the excessive acceleration (EA) criterion, one of five intact stability failure modes, within the second generation intact stability criteria (SGISC) framework, is shown for a set of naval vessels. First and second level vulnerability assessment of the criterion is applied to parent hulls D1 and D5 of D-Systematic Series, the US Office of Naval Research (ONR) Topside Series model, and the European multi-purpose frigate FREMM. All of which are semi-displacement, transom stern, and round bilge hull forms. Relatively low ship roll periods and great variations of hull geometry in vertical direction make this kind of ship potentially vulnerable to the EA phenomenon. Five displacements are considered for each vessel, and the minimum value of the KG height, which satisfies the Level 2 assessment, is computed for each of them. The curve of the minimum allowable KG is compared with the curve of the maximum KG complying with intact stability criteria specified in RINA (Registro Italiano Navale), classification rules for naval ships.

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