scholarly journals Thermophysical properties experimentally tested for NaCl-KCl-MgCl2 eutectic molten salt as a next generation high temperature HTF in CSP systems

2020 ◽  
pp. 1-13
Author(s):  
Xiaoxin Wang ◽  
Jusus Rincon ◽  
Peiwen Li ◽  
Youyang Zhao ◽  
Judith Vidal
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Power Systems ◽  
Molten Salt ◽  
Thermophysical Properties ◽  
Power Plants ◽  
Solar Power ◽  
Thermal Power ◽  
Thermal Storage ◽  
Heat Of Fusion

Abstract A new eutectic chloride molten salt, MgCl2-KCl-NaCl (wt.% 45.98-38.91-15.11), has been recognized as one of the most promising high-temperature heat-transfer fluids (HTF) for both heat transfer and thermal storage for the 3rd Generation concentrated solar thermal power (CSP) systems. For the first time, some essential thermophysical properties of this eutectic chloride molten salt needed for basic heat transfer and energy storage analysis in the application of concentrating solar power systems have been experimentally tested and provided as functions of temperature in the range from 450 °C to 700 °C. The studied properties include heat capacity, melting point, heat of fusion, viscosity, vapor pressure, density, and thermal conductivity. The property equations provide essential database for engineers to use to calculate convective heat transfer in concentrated solar receivers, heat exchangers, and thermal storage for concentrated solar power plants.

scholarly journals Experimental Test of Properties of KCl–MgCl2 Eutectic Molten Salt for Heat Transfer and Thermal Storage Fluid in Concentrated Solar Power Systems

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Xiankun Xu ◽  
Xiaoxin Wang ◽  
Peiwen Li ◽  
Yuanyuan Li ◽  
Qing Hao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Power Systems ◽  
Molten Salt ◽  
Thermal Power ◽  
Eutectic Mixture ◽  
Thermal Storage ◽  
Strength Loss ◽  
Industrial Applications ◽  
Test Results ◽  
Salt Corrosion

The eutectic mixture of MgCl2–KCl molten salt is a high temperature heat transfer and thermal storage fluid able to be used at temperatures up to 800 °C in concentrating solar thermal power systems. The molten salt thermophysical properties are reported including vapor pressure, heat capacity, density, viscosity, thermal conductivity, and the corrosion behavior of nickel-based alloys in the molten salt corrosion at high temperatures. Correlations of the measured properties as functions of molten salt temperatures are presented for industrial applications. The test results of tensile strength of two nickel-based alloys exposed in the molten salt at a temperature of 800 °C from 1-week length to 16-week length are reported. It was found that the corrosion and strength loss is rather low when the salt is first processed to remove water and oxygen.

The Effect of Hydrostatic Pressure and Thermal Load on Buckling Analysis of Large Scale Tank Roof

2020 ◽  
Author(s):  
Qianyu Shi ◽  
Zhijian Wang ◽  
Hui Tang ◽  
Qi Li
Keyword(s):  
High Temperature ◽  
Hydrostatic Pressure ◽  
Power Systems ◽  
Molten Salt ◽  
Large Scale ◽  
Thermal Power ◽  
Buckling Analysis ◽  
Storage Tanks ◽  
Nonlinear Buckling ◽  
Nonlinear Buckling Analysis

Abstract Large scale molten salt storage tanks are widely used in the solar thermal power systems. For these tanks, buckling is a primary failure mode because of its features such as large scale, thinned wall and high temperature. Suffering high temperature condition is a major distinction between molten salt storage tanks and other water or oil tanks. High temperature can cause large thermal deformation for large scale structures which may have an effect on the safety assessment, especially on buckling assessment. Meanwhile, the hydrostatic pressure of molten salt can also cause the change of tank’s configuration. In this paper, a typical large molten salt storage tank has been studied. The critical buckling loads of the tank roof are obtained using nonlinear buckling analysis considering thermal loads and hydrostatic pressure. The results are discussed and some conclusions are proposed for engineering design.

Comparative Optimization on the Focusing Methods of Solar-Electric Dish Stirling System

2012 ◽  
Vol 236-237 ◽  
pp. 714-719
Author(s):  
Wei Lan ◽  
Bin Wang ◽  
Yi Ming Feng
Keyword(s):  
Power Systems ◽  
High Speed ◽  
Power Plants ◽  
Solar Power ◽  
Thermal Power ◽  
Engineering Application ◽  
Solar Thermal ◽  
Solar Thermal Power ◽  
Low Emission ◽  
Practical Engineering

Nowadays, the high-speed economic development has caused significant consumption of energy. While the circumstance is getting severer, solar energy is taken as a kind of clean, environmental friendly resource with infinite storage that has aroused a wide public concern. Photovoltaic and solar thermal are two main categories of solar applications. Because of its high conversion efficiency, low emission and flexible installation, dish Stirling solar power technology is more preferable to be used among the solar thermal area. From the view of practical engineering application, this paper illustrates multiple focusing methods of the current dish Stirling solar power systems in detail, and the comparison of these methods are given to analyze their advantages, disadvantages and their application scenarios. It can be used for the future development of dish Stirling solar power technology and applied as a reference for large dish solar thermal power plants’ installations and tests.

Experimental Investigation of Thermal Storage Processes in a Thermocline Storage Tank

2011 ◽  
Author(s):  
Wafaa Karaki ◽  
Peiwen Li ◽  
Jon Van Lew ◽  
M. M. Valmiki ◽  
Cholik Chan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Storage Tank ◽  
Power Plants ◽  
Thermal Power ◽  
Energy Charge ◽  
Thermal Storage ◽  
Packed Bed ◽  
Heat Transfer Fluid ◽  
Energy Storage Efficiency

This paper presents an experimental study and analysis of the heat transfer of energy charge and discharge in a packed-bed thermocline thermal storage tank for application in concentrated solar thermal power plants. Because the energy storage efficiency is a function of many parameters including fluid and solid properties, tank dimensions, packing dimensions, and time lengths of charge and discharge, this paper aims to provide experimental data and a proper approach of data reduction and presentation. To accomplish this goal, dimensionless governing equations of energy conservation in the heat transfer fluid and solid packed-bed material are derived. The obtained experimental data will provide a basis for validation of mathematical models in the future.

The Green Energy Fraction Parameter for Solar Thermal Power Systems

Solar Energy ◽  
2004 ◽  
Author(s):  
Aharon Roy
Keyword(s):  
Power Systems ◽  
Power Plants ◽  
Solar Power ◽  
Thermal Power ◽  
Energy Performance ◽  
Green Energy ◽  
Energy Fraction ◽  
Environmental Consequences ◽  
Project Assessment ◽  
Hybrid Power

A new solar power parameter, the green energy fraction is proposed as a useful metric for project assessment. Its concept is elucidated and the application to solar/fuel hybrid power plants is exhibited by numerical illustrations. This parameter is a simple tool for tracking the actual green energy performance of a particular plant. It proves to serve a significant yardstick for evaluating fuel avoidance, hence the environmental consequences of solar hybrid power plants. The green energy fraction provides a summation of the fuel avoidance for the whole system, simple or complex, and allows comparative evaluation between power plants for upright green energy (fuel avoidance), and thus enables standard assessments of various systems on an equal basis. It has both thermodynamic and engineering meaning and signifies one of the essential figures of merit for solar power systems. It should assist R&D management to improve technologies. Green energy entitles substantial financial benefits.

Application of Supercritical Pressures in Power Engineering

2017 ◽  
pp. 404-457
Author(s):  
Igor Pioro ◽  
Mohammed Mahdi ◽  
Roman Popov
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
High Temperature ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Thermal Power Plants ◽  
Power Cycles

SuperCritical Fluids (SCFs) have unique thermophyscial properties and heat-transfer characteristics, which make them very attractive for use in power industry. In this chapter, specifics of thermophysical properties and heat transfer of SCFs such as water, carbon dioxide and helium are considered and discussed. Also, particularities of heat transfer at SuperCritical Pressures (SCPs) are presented, and the most accurate heat-transfer correlations are listed. SuperCritical Water (SCW) is widely used as the working fluid in the SCP Rankine “steam”-turbine cycle in fossil-fuel thermal power plants. This increase in thermal efficiency is possible by application of high-temperature reactors and power cycles. Currently, six concepts of Generation-IV reactors are being developed, with coolant outlet temperatures of 500°C~1000°C. SCFs will be used as coolants (helium in GFRs and VHTRs; and SCW in SCWRs) and/or working fluids in power cycles (helium; mixture of nitrogen (80%) and helium [20%]; nitrogen, and carbon dioxide in Brayton gas-turbine cycles; and SCW “steam” in Rankine cycle).

scholarly journals Assessment of Solar Power Tower Driven Ultra Supercritical Steam Cycles Applying Tubular Central Receivers With Varied Heat Transfer Media

2009 ◽  
Author(s):  
Cs. Singer ◽  
R. Buck ◽  
R. Pitz-Paal ◽  
H. Mu¨ller-Steinhagen
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Cost Reduction ◽  
Power Plants ◽  
Reduction Potential ◽  
Solar Power ◽  
Liquid Metals ◽  
Specific Investment ◽  
Temperature Heat ◽  
Electricity Costs

In commercial power plant technology, the market introduction of ultra supercritical (USC) steam cycle power plants with steam parameters around 350bar and 720°C is the next development step. USC steam cycles are also proposed to decrease the levelized electricity costs of future solar power towers due to their highly efficient energy conversion. A 55% thermal efficiency with decreased specific investment costs is within the potential of USC steam cycles. The required process parameters can be achieved using nickel based alloys in the solar receiver, the tubing and other plant components. For solar tower applications, appropriate high temperature heat transfer media (HTM), high temperature heat exchangers and storage options are additionally required. Using the current development for molten salt power towers (Solar Tres) as a reference, several tower concepts with USC power plants were compared. The ECOSTAR methodology provided by [1] was applied for predicting the cost reduction potential and the annual performance of these power tower concepts applying tubular receivers with various HTM. The considered HTM include alkali nitrate salts, alkali chloride salts and liquid metals such as a Bi-Pb eutectic, tin or sodium. For the assessment, an analytical model of the heat transfer in a parametric 360° cylindrical, tubular central receiver was developed to examine the receiver characteristics for different geometries. The sensitivity of the specific cost assumptions for the levelized electricity costs (LEC) was evaluated for each concept variation. No detailed evaluation was done for the thermal storage, but comparable costs were assumed for all cases. The results indicate a significant cost reduction potential for the liquid metal HTM processes.

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