Use of Silica Coated Zinc Nanoparticles for Enhancement in Thermal Properties of Carbonate Eutectic Salt for Concentrated Solar Power Plants

Author(s):  
Syed Muhammad Mujtaba Rizvi ◽  
Yousof Nayfeh ◽  
Baha El Far ◽  
Donghyun Shin

Abstract Concentrated Solar Power (CSP) is one of the most efficient mega-scale renewable Energy sources. However, the overall cost of energy production is not viable for commercial usage and supplanting with fossil fuels or energy produced by nuclear ways. Its operational cost mainly lies in the electrical and thermal systems of the plant. The thermal system comprises of heat storage and heat transfer system. Any enhancement to heat storage or transfer system will directly reduce the cost of operation and increase the yield. Conventionally, oils stable up to 400C were used to transfer and store heat, however more recently, molten salts have been operational in the field for purpose of heat transfer but still, their thermal storage and conduction are limited. The current work explores the possibility of boosting the thermal storage capacity of molten salts through the latent heat of added phase change materials and increasing the specific heat at the same time by adding silica encapsulated zinc nanoparticles. We studied the advantage of adding coated Zn nano-sized particles to carbonate eutectic mixture for enhanced thermal energy storage and heat capacity enhancement. Zinc particles (40nm–60nm) obtained from the commercial sources were coated with silica shells using the solgel process under alkaline conditions. The nano-capsules were then dispersed in a mixture of carbonate salts. A differential scanning calorimeter was employed to characterize the thermal properties of the mixture. Tranmission electron miocroscopy was employed to characterize nanoparticles and electron diffraction Spectroscopy was performed to characterize materials and strcutures involved.

Author(s):  
Ben Xu ◽  
Peiwen Li ◽  
Cholik Chan

With a large capacity thermal storage system using phase change material (PCM), Concentrated Solar Power (CSP) is a promising technology for high efficiency of solar energy utilization. In a thermal storage system, a dual-media thermal storage tank is typically adopted in industry for the purpose of reducing the use of the heat transfer fluid (HTF). While the dual-media sensible heat storage system has been well studied, a dual-media latent heat storage system (LHSS) still needs more attention and study; particularly, the sizing of volumes of storage tanks considering actual operation conditions is of significance. In this paper, a strategy for LHSS volume sizing is proposed, which is based on computations using an enthalpy-based 1D model. One example of 60MW solar thermal power plant with 35% thermal efficiency is presented. In the study, potassium hydroxide (KOH) is adopted as PCM and Therminol VP-1 is used as HTF. The operational temperatures of the storage system are 390°C and 310°C, respectively for the high and low temperatures. The system is assumed to operate for 100 days with 6 hours charge and 6 hours discharge every day. From the study, the needed height of the thermal storage tank is calculated from using the strategy of tank sizing. The method for tank volume sizing is of significance to engineering application.


Author(s):  
Yannan Liang ◽  
Jiemin Zhou ◽  
Ying Yang ◽  
Ye Wu ◽  
Yanyan He

The use of phase-change materials for latent heat storage is a new type of environmentally-friendly energy-saving technologies. Molten salts, one kind of phase-change materials, which have high latent heats, and whose phase transition temperatures match the high temperatures of heat engines, are the most widely used high-temperature phase-change heat storage materials. However, the heat transfer at solid/liquid phase interface belongs to Micro/Nanoscale Heat transfer, lots of the thermal properties of molten salt at melting point is difficult to test. In this investigation, based on the theory that the thermal conductivity can be determined by measuring the speed of the propagation of the solid/liquid phase interface during phase change, a set of system is developed to investigate the thermal conductivity of molten salts at liquid/solid phase transformation point. Meanwhile, mathematical calculation is applied to intuitively simulate the melting and solidifying process in the phase change chamber, by which the error could be analyzed and partly corrected and the result precision could also be increased. And a series of verification experiments have been performed to estimate the precision and the applicability of the measuring system to evaluate the feasibility of the method and measuring system. This research will pave the way to the follow-on research on heat storage at high temperature in industry.


2012 ◽  
Vol 94 ◽  
pp. 174-181 ◽  
Author(s):  
Stéphanie Guillot ◽  
Abdessamad Faik ◽  
Aydar Rakhmatullin ◽  
Julien Lambert ◽  
Emmanuel Veron ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4741 ◽  
Author(s):  
Andrea Cinocca ◽  
Marco Di Bartolomeo ◽  
Roberto Cipollone ◽  
Roberto Carapellucci

The aim of this work was to propose a small-scale Concentrated Solar Power plant using conventional technologies, in order to improve their flexibility and performances, and reinforce their competitiveness compared to traditional systems. Additionally, this study analyzed the possibility of providing continuity of energy production through an optimized hybrid system, which considered thermal energy storage from a gaseous Heat Transfer Fluid, air. It also considered the possibility of recovering part of the energy of the thermodynamic cycle through an Organic Rankine Cycle system with appropriate dimensions. The final outcomes were a 170 kW CSP plant with about 805 MWh of annual electricity production with a global solar capacity of 32.5%, about 900 kWh of thermal storage daily capacity, and an ORC recovery section of 54.2 kW with a specific production of 260 MWh/y.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1063
Author(s):  
Catalina Hernández Moris ◽  
Maria Teresa Cerda Guevara ◽  
Alois Salmon ◽  
Alvaro Lorca

The energy sector in Chile demands a significant increase in renewable energy sources in the near future, and concentrated solar power (CSP) technologies are becoming increasingly competitive as compared to natural gas plants. Motivated by this, this paper presents a comparison between solar technologies such as hybrid plants and natural gas-based thermal technologies, as both technologies share several characteristics that are comparable and beneficial for the power grid. This comparison is made from an economic point of view using the Levelized Cost of Energy (LCOE) metric and in terms of the systemic benefits related to flexibility, which is very much required due to the current decarbonization scenario of Chile’s energy matrix. The results show that the LCOE of the four hybrid plant models studied is lower than the LCOE of the gas plant. A solar hybrid plant configuration composed of a photovoltaic and solar tower plant (STP) with 13 h of storage and without generation restrictions has an LCOE 53 USD/MWh, while the natural gas technology evaluated with an 85% plant factor and a variable fuel cost of 2.0 USD/MMBtu has an LCOE of 86 USD/MWh. Thus, solar hybrid plants under a particular set of conditions are shown to be more cost-effective than their closest competitor for the Chilean grid while still providing significant dispatchability and flexibility.


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