Development Of Thermal Energy Storage Research Articles

A numerical study of the nanoparticles type effects on the atomic and thermal behavior of silica aerogel/paraffine nanostructure in a cylindrical duct: A molecular dynamics approach

The research examines how silica aerogel and paraffin behaved as phase-change materials in thermal energy storage systems using CuO nanoparticles. The significance is in meeting the need for effective energy storage techniques in response to increasing air pollution levels and rising conventional fuel expenses. The study used molecular dynamics simulations to examine the atomic and thermal properties of a silica aerogel/paraffin/CuO nanostructure within a cylindrical duct. This modeling setup allows for a comprehensive exploration of the interactions among different materials within the thermal energy storage system, offering insights into their combined effects on thermal performance and efficiency. Key results include a nanostructure reaching a maximum (Max) velocity (Velo), temperature (Temp), and density of 0.0096 Å/fs, 626 K, and 0.1365 atom/Å3. The thermal performance represented a sample exhibiting a thermal conductivity and heat flux of 1.74 W/m.K and 66.43 W/m2. The significance of this study utilizing the proposed model lied in its potential to advance our understanding of thermal energy storage systems and their applications. Through an examination of the atomic and thermal behavior of silica aerogel/PCM when CuO nanoparticles were present in a cylinder duct, this study made a valuable contribution to the advancement of energy storage solutions that were both more efficient and effective. The findings of this study may serve as a potential for innovative developments in thermal energy storage and aid in the creation of more environmentally friendly and functional energy solutions.

Shape-stabilized phase change composites supported by biomass loofah sponge-derived microtubular carbon scaffold toward thermal energy storage and electric-to-thermal conversion

Integrating conductive carbon supports and organic phase change materials (PCMs) facilitates the development of thermal energy storage (TES) and conversion systems. Herein, we explore a novel phase change composite (PCC) based upon biomass-derived carbon scaffold incorporating polyethylene glycol (PEG) as a heat storage unit, which demonstrated a combination of good shape-stabilization, high thermal energy storage, and efficient electric-to-thermal conversion property. The carbon scaffold with a hollow microtubular structure was made from biomass loofah sponge (LS) through high-temperature carbonization in nitrogen. Compared with natural LS, the derived carbon scaffold exhibited favorable structural characteristics including a large specific surface area of 668.75 m2/g and a prominent micropore area of 303.37 m2/g, which could not only prevent PEG from leakage but also provide thermally and electrically conductive pathways in the PCM substance. The fabricated PCC displayed high thermal energy storage density (up to 137.6 J/g), outstanding electric-to-thermal conversion, enhanced thermal resistance, and robust temperature regulation properties. It provides an insightful strategy for fabrication and utilization of biomass-derived carbon scaffold based shape-stabilized PCCs in solar thermal energy storage, thermal management and thermoregulated textiles, and infrared stealth of important military targets, etc.

Development of multilayer interacted characteristic melting region for large-scale horizontal latent heat storage investigation

The development of thermal energy storage (TES) technology has aroused extensive attentions due to its considerable energy-saving benefits. In the current work, the strategy of multilayer interacted characteristic melting region (MCR) was established to characterize large-scale horizontal latent heat thermal energy storage (LHTES). Based on the shell-and-tube configuration, the influence of multilayer interaction was numerically investigated and the single-tube approach was found to be inapplicable to characterize the melting performance of horizontal LHTES devices. Furthermore, the characterization strategy with MCR was applied to reexamine typical eccentric design and quite different rules were concluded. The melting performance of cases with intersection angles ranging from 60° to 120° and the tube eccentricity ranging from 0 to 0.6 were established and compared. For the design of eccentric side fins, horizontally spreading heat transfer structures was found to be a better choice, which extended the area dominated by the natural convection above the tubes. The full melting time of the case with the intersection angle of 90° was reduced by 2.9 % and 6.2 % compared with the case with intersection angles of 60° and 120°, respectively. The eccentric tube arrangement was found to have negative influence on the melting performance for large-scale horizontal LHTES devices. The full melting time of the case with the fin-tubes eccentricity of 0.6 was increased by 23.3 % compared with the concentric design.

Compressed Air Energy Storage—An Overview of Research Trends and Gaps through a Bibliometric Analysis

Electrical energy storage systems have a fundamental role in the energy transition process supporting the penetration of renewable energy sources into the energy mix. Compressed air energy storage (CAES) is a promising energy storage technology, mainly proposed for large-scale applications, that uses compressed air as an energy vector. Although the first document in literature on CAES appeared in 1976 and the first commercial plant was installed in 1978, this technology started to gain attention only in the decade 2000–2010, with remarkable scientific production output and the realization of other pre-commercial demonstrators and commercial plants. This study applies bibliometric techniques to draw a picture of the current status of the scientific progress and analyze the trend of the research on CAES and identify research gaps that can support researchers and manufacturers involved in this entering technology. Recent trends of research include aspects related to the off-design, the development of thermal energy storage for adiabatic CAES, and the integration of CAES with combined heating and cooling systems.

Influence of Water Addition on the Latent Heat Degradation of Sodium Acetate Trihydrate

To promote the development of thermal energy storage (TES), the sodium acetate trihydrate (SAT) presents interesting thermal properties. However, this material may suffer from aging throughout thermal cycles. Various solutions were explored in the literature to limit this aging, mainly based on the use of additives such as water. In this study, two samples were prepared. The first one consisted of raw SAT material whereas 3 wt.% of supplementary water has been added to the second one. They were then poured into 350 cm3 bricks, which were placed in an experimental test bench. After 35 cycles between 20 and 70 °C, a drop of about 10% of the latent heat was observed for the first sample. This behavior was like the literature data. For the second sample, the decrease of latent heat was more rapid (about 30%). Contrary to our expectations, the water addition seems not beneficial for the improvement of thermal stability. Interestingly, we noticed that the drop of the latent heat was fully reversible after sample stirring. This degradation might not be related to a thermal destructive mechanism but rather to a global segregation phenomenon. This segregation may be due to the breaking of hydrogen bonding between anhydrous sodium acetate and water, resulting in the separation of the two species.

Characterization of Stearic Acid and Paraffin Incorporated with Aluminium as Filer for the Development of Phase Change Material Composite in Thermal Energy Storage

With the increasing energy demand, shortage of energy has drawn attention towards the utilization of non-renewable energy sources. The development of thermal energy storage (TES) to fulfil the energy demand that has increased progressively over time is of great interest. TES systems are widely employed industrially especially for phase change materials (PCM) used in many fields with several applications. This study aims to synthesize, characterize and study the physicochemical and thermal properties of stearic acid and paraffin incorporated with aluminium as filler for the development of PCM composite. The PCM composites were prepared using 80wt% for the Al/SA and 80wt% Al/paraffin, respectively. The PCM composites were characterized using thermal gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. Results showed good compatibility in physicochemical properties between stearic acid (SA), paraffin and aluminium (Al), respectively. It was observed that the thermal stability studied using thermal gravimetric analysis revealed slightly better stability exhibited by the paraffin PCM composite. This was as a result of the steeper slope exhibited by the stearic acid TGA curve as against that of the paraffin curve. Also, density analysis has resulted in an increment for both composite materials whereas; aluminium incorporated in paraffin composite has shown higher increment of density as compared with stearic acid composite. Therefore, PCM composite made from paraffin will be more effective as a TES material when used industrially as compared to the stearic acid PCM composite.

Design analysis of a particle-based thermal energy storage system for concentrating solar power or grid energy storage

• Grid-scale energy storage is critical to the growing renewable power integration. • Thermal energy storage (TES) can provide long duration, grid-scale energy storage. • TES using solid particles can be a feasible storage method to support various power cycles. • A containment design method is presented for the particle-based TES. Energy storage is becoming indispensable for increasing renewable energy integration, and it is critical to the future low-carbon energy supply. Large-capacity, grid scale energy storage can support the integration of solar and wind power and support grid resilience with the diminishing capacity of baseload fossil power plants. With the development of thermal energy storage (TES) for concentrating solar power systems, standalone TES for grid integration becomes attractive due to the declining renewable generation cost and an increasing need for energy storage. The standalone TES system introduced in this paper can play a big role in the carbon-free energy future with capacity larger than batteries and cost likely lower than other energy storage methods such as pumped storage hydropower and compressed air energy storage, both of which also have geological limitations. To this end, we describe a TES system that uses stable, inexpensive solid particles as a TES media to provide scalable, low cost energy storage. The particle-based TES has the ability to drive various thermal power cycles including conventional steam-Rankine, air Brayton turbine with combined-cycle ability, or the emerging supercritical carbon dioxide Brayton power cycle. This work describes the containment design method including a concrete silo and an internal-insulation layer for the particle-TES system. The economic analysis shows significantly low storage cost when the particle-TES is integrated with Brayton combined-cycle power generation. The paper shows the design approach of the particle-TES system and its economic potential for bulk energy storage. The advantage of the particle-TES system as a promising bulk energy storage method is its ability to economically support dispatchable renewable grid penetration for larger capacity and longer discharging hours than current battery storage technologies.

Damage analysis of 601 nickel superalloy in eutectic Na2CO3/NaCl molten salt under isothermal and thermal cycling conditions

Establishing compatibility of high-temperature nickel alloys with molten salt phase-change materials is critical for the development of thermal energy storage for future concentrating solar power systems. This paper investigates the behaviour of alloy 601 in a 59.5 %wt Na2CO3/40.5 %wt NaCl eutectic salt mixture under thermal cycling and isothermal conditions. Under both conditions it was found that chromium was depleted from the alloy at a linear rate, inducing porosity in the metal. The corrosion scale consisted primarily of iron oxide, although chromium and aluminium are present in the inner layers. The scale was found not to be protective and does not form a barrier to salt ingress into the alloy’s porous region, enabling depletion to continue unimpeded. Thermal cycling tests show scale depletion and thickness reduction compared to isothermal tests, implying that depletion and scale growth is related to the time which the salt is molten in the system. Given solar thermal energy using phase-change salt storage is cyclic, this work provides significant insight into corrosion under in-service conditions, which is critical for successful plant design.

Mg-Based Hydrogen Absorbing Materials for Thermal Energy Storage—A Review

Utilization of renewable energy such as solar, wind, and geothermal power, appears to be the most promising solution for the development of sustainable energy systems without using fossil fuels. Energy storage, especially to store the energy from fluctuating power is quite vital for smoothing out energy demands with peak/off-peak hour fluctuations. Thermal energy is a potential candidate to serve as an energy reserve. However, currently the development of thermal energy storage (TES) by traditional physical means is restricted by the relatively low energy density, high temperature demand, and the great thermal energy loss during long-period storage. Chemical heat storage is one of the most promising alternatives for TES due to its high energy density, low energy loss, flexible temperature range, and excellent storage duration. A comprehensive review on the development of different types of Mg-based materials for chemical heat storage is presented here and the classic and state-of-the-art technologies are summarized. Some related chemical principles, as well as heat storage properties, are discussed in the context. Finally, some dominant factors of chemical heat storage materials are concluded and the perspective is proposed for the development of next-generation chemical heat storage technologies.

Development of Thermal Energy Storage as a Supplemental Heat Source for Solar Dryer

The current work presents about the development of thermal energy storage (TES) using paraffin wax as a phase change material (PCM). In order to investigate the performance of TES as a supplemental heat source for solar dryer when no sunshine, the TES was connected with solar dryer having maximum capacity for 10 kg of fresh chilies. The TES unit consists of 28.35 kg PCM and copper tube inside the cylindrical tank. The charging process of the TES is carried out with the help of electrical heater. The paraffin wax in the TES starts to melt and absorb the energy till it turns to liquid state. For heat discharging process during the off sunshine hours, air with mass flow rate of 0.0023 kg/s at ambient temperature can be passed through the copper tube in the TES in order to provide hot air for the dryer. From the performance analysis results, it is observed that the temperature of drying chamber can be maintained about 40-50 °C for 3 hours at least after sunset and higher than ambient temperature about 16.72 °C. The novel design of TES successfully increases the performance of the drying systems and reduces the time for drying process.

Optimum output temperature setting and an improved bed structure of metal hydride hydrogen storage reactor for thermal energy storage

As the well-known solid hydrogen storage materials, metal hydrides (MHs) have been developed systematically for decades. During recent years, due to the development of thermal energy storage (TES) market, they have also received much attention gradually as the excellent TES materials because of the high energy density, low cost, and good reversibility. In this study, the stabilized discharging performance of an MH reactor for TES was investigated by numerical simulation. A mathematical model combining multi-physics and proportional-integral controller was established. Based on finite-time thermodynamics, gravimetric exergy-output rate (GEOR) considering the control requirement, finite-material, and finite-time constraints was defined. For a given reactor, the output temperature setting could be optimized based on GEOR. Besides, the effects of the reactor parameters on the optimum output temperature setting were systematically studied. The heat transfer analysis indicated the occurrence of the axial non-uniform reaction in the bed due to the inherent increase in the temperature of heat transfer fluid, resulting in the decrease of both GEOR and material availability. Accordingly, a new tapered bed structure (L/Do = 600/50 mm) was proposed to effectively improve the discharging efficiency from 76 to 90% and GEOR from 65 to 120 W kg−1, which provides a helpful guidance for the advanced designing and construction of MH reactor for the practical TES applications.

Utilization of macro encapsulated phase change materials for the development of thermal energy storage and structural lightweight aggregate concrete

Structural–functional integrated materials are one of directions of rapid development for saving-energy materials. Phase Change Materials (PCMs) are latent thermal storage materials possessing a large amount of heat energy stored during its phase change stage. Porous lightweight aggregate (LWA) can serve as the carrier for PCM. In this research, a structural concrete with function of indoor temperature control were prepared by using macro encapsulated PCM–LWA. The indoor and outdoor tests were performed to determine the thermal performance of the lightweight aggregate concrete (LWAC) containing macro encapsulated Paraffin–LWA. The compressive strength and shrinkage strain of LWAC with macro encapsulated PCM–LWA were evaluated. Finally, the economic and environmental aspects of application of macro encapsulated Paraffin–LWA in a typical floor area of public housing rental flat in Hong Kong were assessed.From indoor thermal performance test, it was found that LWAC incorporated with macro encapsulated Paraffin–LWA has a function of reducing the energy consumption by decreasing the indoor temperature; flatten the fluctuation of indoor temperature and shifting the loads away from the peak periods. Moreover, from outdoor thermal performance test, it was found that the performance of macro encapsulated Paraffin–LWA in adjusting the room temperature was optimized when there was a remarkable temperature difference between the day and night. Test results showed that the compressive strengths of LWAC incorporating macro encapsulated Paraffin–LWA at 28days was higher than control LWAC (without macro encapsulated Paraffin–LWA) and was found to be over 15MPa. The shrinkage strain reduced with the incorporation of macro encapsulated Paraffin–LWA in LWAC and therefore has a beneficial effect on the volume stability of LWAC. From simple economic evaluation of macro encapsulated Paraffin–LWA in a typical floor area of public housing rental flat in Hong Kong, the recovery or payback period was found to be less than the average life span of a residential building in Hong Kong. Therefore, incorporation of macro encapsulated Paraffin–LWA in LWAC building walls is economically feasible. Finally, from environmental prospect, a reduction of 465kgCO2-eq/year or 12.91kgCO2-eq/year/m2 was achieved. This reduction would contribute to mitigate Greenhouse Gases emissions over the life span of building. It can therefore be concluded that the developed macro encapsulated PCM LWAC can be used for thermal and structural applications in buildings.

Thermochemical energy storage at high temperature via redox cycles of Mn and Co oxides: Pure oxides versus mixed ones

Development of thermal energy storage (TES) systems for concentrated solar power (CSP) is essential in order to match a variable electricity demand with an intermittent energy source supply, enhancing energy generation dispatchability. The high energy storage densities and the possibility of working at higher temperature ranges make thermochemical heat storage (TCS) via reduction–oxidation (redox) cycles of metal oxides a promising concept for energy storage. For this purpose, manganese and cobalt oxides have been selected as feasible candidates due to their favourable thermodynamic properties. In order to explore the potential of these materials, the capacity of both pure (Mn2O3 and Co3O4) and mixed oxides (Mn3−xCoxO4) to withstand several charge–discharge cycles was evaluated by thermogravimetrical analysis. Results showed better cyclability for the mixed oxides with low Mn content (x≥2.94) and, specially, for the corresponding pure oxides, confirming that these materials may be a viable option for TCS.

Concentrating Solar Power in Europe, the Middle East and North Africa: A Review of Development Issues and Potential to 2050

This paper summarizes the findings of a study undertaken by the European Academies Science Advisory Council to evaluate the development challenges of concentrating solar power (CSP) and its consequent potential to contribute to low carbon electricity systems in Europe, the Middle East and North Africa (the MENA region) to 2050. The study reviewed the current status and prospective developments of the four main CSP technology families, and identified prospective technical developments, quantifying anticipated efficiency improvements and cost reductions. Similarly, developments in thermal energy storage were evaluated, and the role and value of CSP storage in electricity systems were examined. A key conclusion was that as the share of intermittent renewables in an electricity system increases, so does the value of thermal energy storage in CSP plants. Looking ahead, the study concludes that CSP should be cost competitive with fossil-fired power generation at some point in the 2020’s provided that commercial deployment continues at an increasing rate, and through support mechanisms that incentivise technology development. Incentive schemes should reflect the real value of electricity to the system, and should ensure sufficient transparency of cost data that learning rates can be monitored. Key factors which will determine CSP’s contribution in Europe and the MENA region over the period to 2050 are generating costs, physical constraints on construction of new plants and transmission, and considerations of security of supply. The study makes recommendations to European and MENA region policy makers on how the associated issues should be addressed.

Thermal Energy Storage (TES): Optimizing the Economics of Energy and Capital

ABSTRACT Recent significant trends and developments in thermal energy storage (TES) are presented and discussed. 1. Specifically, there is an increasing number of large capacity applications of TES. The types of large applications include district cooling utilities, institutional, and private commercial or industrial users, where TES provides demand management; other increasing TES applications include turbine inlet cooling (TIC) for hot weather power enhancement of gas turbine-based power plants.2. TES systems are often designed for lower than traditional supply temperatures, or dual-designed for initial conventional supply temperatures but also for potential future lower temperatures with higher system capacities.3. Energy efficiency of TES systems, both on-site at the energy user and at source energy power plants, is explored to demonstrate the potential for significant efficiency and environmental benefits.4. Economics are examined to document how large TES installations, when applied at times of either new facility construction or chiller plant capacity expansion/rehabilitation, often provide not only major operating cost benefits but even dramatic capital cost savings versus conventional (non-TES) chiller plant capacity. Actual case studies are briefly explored to illustrate each of these aspects of TES systems.

Developments in Thermal Energy Storage: Large Applications, Low Temps, High Efficiency, and Capital Savings

ABSTRACT Some significant recent trends and developments in thermal energy storage (TES) are presented and discussed. In particular, an increasing number of large capacity applications are evident. Types of large applications include campus cooling networks and district cooling utility developments, where TES provides demand management for energy users, as well as turbine inlet cooling (TIC) applications for hot weather power enhancement of power plants for electric energy generators. Systems are often designed for lower than traditional supply temperatures, or dual-designed for initially conventional supply temperatures but also lower future temperatures with higher storage capacities. The energy efficiency of TES systems, both on-site at the energy user and at-source energy power plants, is explored. Economics are examined to document how large TES installations, when applied at times of either new facility construction or chiller plant capacity expansion/rehabilitation, often provide not only major ope...

PCR in forensic science

Development of thermal energy storage (TES) systems for concentrated solar power (CSP) is essential in order to match a variable electricity demand with an intermittent energy source supply, enhancing energy generation dispatchability. The high energy storage densities and the possibility of working at higher temperature ranges make thermochemical heat storage (TCS) via reduction–oxidation (redox) cycles of metal oxides a promising concept for energy storage. For this purpose, manganese and cobalt oxides have been selected as feasible candidates due to their favourable thermodynamic properties. In order to explore the potential of these materials, the capacity of both pure (Mn2O3 and Co3O4) and mixed oxides (Mn3−xCoxO4) to withstand several charge–discharge cycles was evaluated by thermogravimetrical analysis. Results showed better cyclability for the mixed oxides with low Mn content (x≥2.94) and, specially, for the corresponding pure oxides, confirming that these materials may be a viable option for TCS.

Baseload solar power: Near-term prospects for load following solar thermal electricity

We explore prospects for future improvements in solar thermal electricity generation, focusing in particular on advanced parabolic trough technology, coupled with natural gas back up and potential developments in thermal energy storage. Based on recent developments achieved at the University of Sydney, Australia, and elsewhere, it appears that the performance and economics of solar thermal technology could be improved beyond the unprecedented results already achieved by the now defunct Luz International Limited. If such improvements are realized, solar thermal power could become competitive within this decade as a principal source of electricity (rather than just peaking power) over much of the USA, including large portions of the Mid-west and the South-east. Coupled with natural gas back up and potential developments in thermal energy storage, baseload solar plants may be feasible with solar fractions exceeding 80%. While much engineering and economic refinement remains to be done, preliminary economic estimates suggest that a hybrid solar/storage/gas plant could produce load following solar electricity around the clock for a levelized real cost of five to seven cents per kilowatt hour over large regions of the USA.