Heat transfer enhancement in latent heat thermal energy storage system
About: This article is published in Journal of Enhanced Heat Transfer.The article was published on 2017-01-01. It has received 4 citations till now. The article focuses on the topics: Latent heat & Heat transfer enhancement.
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01 Oct 2021
TL;DR: In this article, high-temperature latent heat storage (LHS) using phase change medium (PCM) can be a promising alternative to address the challenges of variable renewable energy generation with respect to time and space.
Abstract: Limited reserves of fossil fuels, increased world energy demand and swelling of environment pollution drive a transition towards renewable energy resources which can deliver 3E objectives (Economic, environmental and energy security). However, the inherent intermittency necessitates efficient energy storage systems to harness the true potential of renewable resources. In this context, high-temperature latent heat storage (LHS) using phase change medium (PCM) can be a promising alternative to address the challenges of the variable renewable energy generation with respect to time and space. Currently, central receiver-based 3rd Gen concentrated solar thermal (CST) plant operating at high-temperatures (800-1000 °C) is the most attractive technology to convert solar energy to heat. Moreover, advanced power-generating cycles such as supercritical CO2 (sCO2) Brayton cycle operating at high-temperature can reduce the Levelized cost of Energy (LCoE) by achieving higher cycle efficiency. Hence, coupling a high-temperature LHS between the central receiver system and sCO2 cycle can have dual benefits: increase in dispatchability of energy and reduction in LCoE. Furthermore, high-temperature LHS can be devised to store high-grade energy such as spillage of energy from Photovoltaic (PV), wind power plant, and waste heat from energy-intensive industries (e.g. glass melting furnace). This article reports a holistic approach to review different components and design aspects of high-temperature LHS with techno-economic challenges to be overcome. A preliminary numerical study has been performed to predict the melting behavior of high-temperature silicon using COMSOL Multiphysics. Based on the review, two configurations of high-temperature LHS have been illustrated to produce continuous and cost-effective electricity. The first layout is high-temperature LHS coupled with 3rd generation (Gen) CST and the second one is a standalone high-temperature LHS device with Thermionic-photovoltaic (TIPV) diode.
13 citations
TL;DR: In this paper, an organic phase-change material for enhanced energy storage was prepared by adding SiO2 particles in a certain proportion into molten palmitic acid (PA) with stirring and intensive sonication at a constant temperature.
Abstract: Organic phase-change material for enhanced energy storage was prepared by adding SiO2 particles in a certain proportion into molten palmitic acid (PA) with stirring and intensive sonication at a constant temperature. The thermal properties of the SiO2/PA composite were experimentally characterized. As compared with the pure PA, the latent heat capacity of the composite with addition of 3 wt% SiO2 particles is increased by 51.7 kJ/kg, reaching 214.7 kJ/kg, which is the highest value among the composites tested with varying SiO2 ratio from 1 to 5 wt%; the thermal conductivity of the 3 wt% SiO2/PA composite is also increased by 12% at 30 oC (solid state) and 7% at 70 oC (liquid state), respectively. A water heater was built and tested with embedded capsules containing the 3 wt% SiO2/PA composite and pure PA, respectively. The lab-built phase-change water heater is much smaller in size than an ordinary household water heater in comparison and uses reduced electrical power. However, it responds faster and has a larger volume ratio of hot water output to water heater size. During the 2 turning-off test, the water heater with 3 wt% SiO2/PA can provide 2.23 times hot water of heater size; while the ordinary water heater can only provide 1.41 times hot water volume of tank size.
6 citations
TL;DR: In this article, two collectors with the same area of 945×420$945 times 420$ mm have been designed and fabricated: one flat plate collector with internally grooved fins inserted inside the riser tubes and the other one with plain riser tube.
Abstract: Abstract Two collectors with the same area of 945×420$945\\times 420$ mm have been designed and fabricated: one flat plate collector with internally grooved fins inserted inside the riser tubes and the other one with plain riser tubes. Provisions were made for inserting the T-type thermocouples at six different locations to monitor temperature variations inside the riser tubes of the collector. The two identical systems of collectors (finned and unfinned tube) were initially run with base working fluid (water) and then with Al2O3 nanoparticles with a size of 40 nm for different weight fractions of 0.2$0.2$ % and 0.4$0.4$ % in incremental order to study the effect on the efficiency of collectors. Mixing of nanoparticles in water thus improves the efficiency of the collector. Results show the efficiency of finned tube collector using the nanoparticles and water is substantially higher when compared to that of unfinned riser tubes collector.
5 citations
Cites background from "Heat transfer enhancement in latent..."
...Lacroix [12] and Zhang and Faghri [13] showed that adding ns to the phase change material (PCM) side of the thermal energy storage system is an e cient way to enhance heat transfer in a latent heat thermal energy storage system if a high thermal conductive uid is used as transfer uid inside the tube....
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