High Thermal Energy Research Articles

Metallic wood-based phase change material with superior anisotropic thermal conductivity and energy storage capacity

In this study, metallic wood-based phase change material (MWM) with high performance anisotropic thermal conductivity and energy storage capacity was developed by impregnating wood with myristic acid, and subsequent introducing low melting point alloy (LMA) into the wood through a facile alternating high and low temperature heat treatment. The heat-driven LMA was rapidly squeezed into the cell lumens of the wood so as to effectively inhibit the leakage of the internal myristic acid during melting. Benefited with the well-aligned and hierarchical porous structure, the filled LMA formed a continuous heat transfer network along the highly oriented transport tissue of wood, which could greatly reduce the interfacial thermal resistance and promote heat transfer. Compared with untreated wood, the thermal conductivity of MWM in longitudinal and radial directions were improved by more than 67 % and 75 %, respectively. In addition, it exhibited superior energy storage capability, with the latent heat of 90.23 J/g and 86.42 J/g during melting and solidification. The thermal stability and anti-leakage performance were satisfied. The phase change temperatures, enthalpies and chemical structure of MWM remained unchanged after 100 thermal cycles, demonstrating outstanding cycling reliability. With excellent energy storage performance and favourable thermal conductivity, the prepared MWM shows a promising application in energy saving buildings and solid wood floors.

High thermal energy storage of the two-dimensional Al2Te3 semiconductor: DFT study of stability, electronic, phonon, thermal, and optical properties based on GGA and HSE06

The present study investigates the structural, electronic, thermal, and optical properties of a novel two-dimensional Al2Te3 using GGA and HSE06 functional in the framework of density functional theory. The formation energy, the phonon dispersion, and AIMD calculations confirm the structural, dynamical, and thermal stability of Al2Te3, respectively. The electronic band structure and partial density of states indicate the semiconducting characteristics of 2D Al2Te3 with band gap values of 1.92 eV (GGA) and 2.78 eV (HSE06). The thermal properties of Al2Te3 reveal a high heat capacity due to a very high phonon density of states. This property signifies the material's growing ability to store thermal energy. Thus the entropy demonstrates a continuous increase with temperature, adhering to the second law of thermodynamics. The analysis of optical properties of Al2Te3 demonstrates strong light interaction in the ultraviolet, UV, region, and the optical band gap is found to be larger than the electronic band gap for both GGA and HSE06 functional due to indirect behavior of the band gap. Furthermore, the static dielectric function, refractive index, and optical conductivity are found to be smaller in the case of HSE06 compared to the GGA which may be due to reduced transition probability, and less screening effects including in the HSE06 functional. These findings offer valuable insights into the potential applications of Al2Te3 in various fields, including thermal energy storage and optoelectronics.

A More Transparent Infrared Window

AbstractThe infrared window region (780–1,250 cm−1, 12.8 to 8.0 μm) is of great importance to Earth's climate due to its high transparency and thermal energy. We present here a new investigation of the transparency of this spectral region based on observations by interferometers of downwelling surface radiance at two DOE Atmospheric Radiation Measurement program sites. We focus on the dominant source of absorption in this region, the water vapor continuum, and derive updated values of spectral absorption coefficients for both the self and foreign continua. Our results show that the self continuum is too strong in the previous version of Mlawer‐Tobin_Clough‐Kneizys‐Davies (MT_CKD) water vapor continuum model, a result that is consistent with other recent analyses, while the foreign continuum is too weak in MT_CKD. In general, the weaker self continuum derived in this study results in an overall increase in atmospheric transparency in the window, although in atmospheres with low amounts of water vapor the transparency may slightly decrease due to the increase in foreign continuum absorption. These continuum changes lead to a significant decrease in downwelling longwave flux at the surface for moist atmospheres and a modest increase in outgoing longwave radiation. The increased fraction of surface‐leaving radiation that escapes to space leads to a notable increase (∼5–10%) in climate feedback, implying that climate simulations that use the new infrared window continuum will show somewhat less warming than before. This study also points out the possibly important role that aerosol absorption may play in the longwave radiative budget.

A novel kapok fiber aerogel based phase change materials with high thermal conductivity and efficient energy storage for photovoltaic thermal management

In response to the evolving energy crisis and environmental changes, solar photovoltaic systems are progressively emerging as common substitutes to fossil fuels. However, the substantial heat accumulation on the surface of photovoltaic panels significantly impacts their photoelectric performance. Consequently, effective thermal management solutions are essential to address these key issues. In this study, a novel composite phase change material (TD@CKF-PVA) was designed. It utilizes a three-dimensional network structure constructed from cross-linked polyvinyl alcohol (PVA) and kapok fiber (KF) as the scaffold, and 1-tetradecanol (TD) as the phase change material. This composite material exhibits excellent thermal conductivity of 0.93 W/mK and efficient thermal energy storage capacity of 204 J/g. The coating of carbon nanotubes on KF provides additional thermal pathways, significantly enhancing the thermal conductivity of the phase change composite material. TD@CKF-PVA phase change materials also demonstrate outstanding thermal management capabilities in both time and space dimensions, effectively reducing the heat accumulation on solar photovoltaic panels and improving their output power and photoelectric efficiency. This work not only showcases the great potential of TD@CKF-PVA for thermal energy management but also provides an efficient approach to dissipating heat from PV panels.

Experimental Investigations on the Comparison of Multi-Objective Design for High Thermal Energy Applications: An Insight into Response Surface Methodology

ABSTRACT This paper focuses on optimizing the thermal properties of aluminum, copper, and iron. Response Surface Methodology was employed to determine the optimal values for thermal conductivity and thermal expansion, minimizing experimental repetitions, and reducing costs by using pre-determined input parameters. These parameters include the volume percentages of aluminum, copper, and iron. The optimized output values for thermal conductivity and thermal expansion are measured using the two-probe method and buoyancy method, respectively, and inferred from ANOVA. The Response Surface Methodology is utilized for optimization, and various approaches analyzed include Central-Composite-Design, Box-Behnken-Design, Full-Factorial-Design, and Optimal-I method. For Central-Composite-Design, deviations are 1.07 for thermal conductivity and 0.98 for thermal expansion, with R2 values of 0.9898 and 0.9355 and F values of 96.910 and 29. For Full-Factorial-Design, deviations are 39.42 for thermal conductivity and 26.83 for thermal expansion, with R2 values of 0.86 and 0.89 and F values of 20.2936 and 17.3521. For BBD, deviations are 13.49 for thermal conductivity and 22.47 for thermal expansion, with R2 values of 0.9756 and 0.9768, and F values of 66.5 and 70.1. For Optimal-I, deviations are 12.67 for thermal conductivity and 22.56 for thermal expansion, with R2 values of 0.9937 and 0.9793, and F values of 87.38 and 63.02.

Enhancing building energy efficiency: Numerical analysis of a hybrid thermoelectric ventilation system and earth-air heat exchange with photovoltaic-thermoelectric power integration for heating and cooling loads

The lack of studies on hybrid systems combining thermoelectric ventilation (TEV) and earth-air heat exchangers with a photovoltaic-thermoelectric generator (PV-TEG) as the power supply for the hybrid system is addressed in this research. This study aims to investigate the effectiveness and performance of such a combined system in providing the required thermal load of a building. To simulate the performance of TEV and PV-TEG systems, energy conservation equations for various components of the system were formulated for the quasi-state mode. The performance of the earth-air heat exchanger system was evaluated using the effectiveness-number of transfer units method. The resulting set of algebraic equations was then solved using a MATLAB code. Results indicated significant preheating (5.41–15.03 °C) and precooling (0.7–10.22 °C) effects during the daily hours of 15-February and 15-July, respectively. Additionally, the TEG component effectively reduced PV temperatures by 3.54 °C–16.99 °C in 15-February and 3.99 °C–21.54 °C in 15-July. The system also demonstrated a high monthly useful thermal energy output (1215–1584 kWh) in the cold months (December to March), contrasting with higher monthly useful thermal exergy (712–763 kWh) in the summer months. Furthermore, increasing the number of TEGs from 10 to 50 resulted in significant improvements in the yearly average energy and exergy proficiency indexes (PIya,en and PIya,ex) by 164.97 % and 459.82 %, respectively. The supply air mass flow rate and the length and depth of the earth-air duct were identified as the second and third most influential parameters affecting these indexes. Moreover, the system at CPV concentration ratio of 3 provided the highest PIya,en and PIya,ex of 1.512 and 14.65, respectively.

Multiphysics Field Coupled to a Numerical Simulation Study on Heavy Oil Reservoir Development via Electromagnetic Heating in a SAGD-like Process

Conventional thermal recovery methods for heavy oil suffer from significant issues such as high water consumption, excessive greenhouse gas emissions, and substantial heat losses. In contrast, electromagnetic heating, as a waterless method for heavy oil recovery, offers numerous advantages, including high thermal energy utilization, reduced carbon emissions, and volumetric heating of the reservoir, making it a focus of recent research in heavy oil thermal recovery technologies. This paper presents a numerical simulation study of electromagnetic heating for heavy oil recovery, using a heavy oil block in the Bohai Bay oilfield in China as a case study. Firstly, a multiphysics field coupled to a mathematical model was established, considering the impact of the temperature on the heavy oil viscosity, the threshold pressure gradient of non-Darcy flow, and the dielectric properties of the reservoir, along with heat dissipation from overlying and undercover sandstone and gravitational effects on fluid flow. Secondly, a numerical simulation method for the coupled multiphysics fields was developed, and the convergence and stability of the numerical simulation method were tested. Finally, a sensitivity analysis based on the numerical simulation results identified the factors affecting heavy oil production. It was found that electromagnetic heating significantly enhances heavy oil production, and the threshold pressure gradient greatly influences the prediction of heavy oil production. Moreover, heat dissipation from the overlying and undercover sandstone severely reduces cumulative oil production. When the production well is located below the electromagnetic heating antenna, larger well spacing results in higher cumulative heavy oil production. Higher heavy oil production is achieved when the antenna is positioned at the center of the reservoir for the studied cases. Power has a big effect on increasing heavy oil production, but its influence diminishes as power increases. There exists an optimal range of electromagnetic frequencies for maximum cumulative production, and higher water saturation leads to poorer electromagnetic heating efficiency. This study provides a theoretical foundation and technical support for the numerical simulation technology and development plan optimization of heavy oil reservoirs subjected to electromagnetic heating.

Research and Application of Electromagnetic Heating Device for Digital Well Site Crude Oil Export

Abstract Most well sites have discontinued using the associated gas-fired furnaces in response to the current situation in the oil fields. Coal-fired heating furnaces are environmentally polluting and prohibited due to local environmental regulations. These two heating methods can cause high costs, poor heating efficiency, and environmental pollution, which cannot be achieved through remote digital monitoring. Research has been conducted on the digital electromagnetic heating device for crude oil in the well site, focusing on introducing its main components and functions, including the electromagnetic heating body, frequency conversion control cabinet, and digital remote monitoring terminal. This device provides one-way internal heating without a heat source, resulting in high thermal efficiency, safety, environmental friendliness, and energy conservation. It comprehensively addresses the drawbacks of traditional electric heating, characterized by low efficiency, susceptibility to damage, and difficult maintenance. In 2022, it was applied at three well sites in the Tongzhai operation area of the Third Oil Production Plant of Changqing Oilfield, replacing the existing gas-fired and coal-fired heating furnaces to heat crude oil, as well as heating the heating belt and various electric heating pipes. This device is highly efficient, safe, environmentally friendly, and energy-saving. Additionally, the temperature and pressure of electromagnetic heating crude oil can be digitally and remotely monitored.

Thermal stable NaMgLaTeO6:Dy3+ double perovskite yellow phosphors for w-LEDs and latent fingerprint visualization

The novel Dy3+-doped NaMgLaTeO6 (NaMgLaTeO6:Dy3+) phosphors were produced through a high-temperature solid-state reaction. X-ray diffraction (XRD) analysis and Rietveld refinement manifest that the pure phosphor was committed to the space group (P21/m (11)) and features the double perovskite structure. The band gap (Eg) of the direct semiconductor NaMgLaTeO6 is calculated to be 2.065 eV. Under 388 nm excitation, the 4F9/2→6H13/2 energy level transition contributes to the maximum emission peak at 572 nm. Other properties of the phosphor include optimal concentration (x = 5 mol %), high thermal stability, activation energy (Ea = 0.31 eV), and internal quantum efficiency (IQE = 31.44 %). The relevant color coordinate of the white light emitting diode (w-LED) prepared by the phosphor is (0.298, 0.311). The features of the latent fingerprint (LFP) created by NaMgLaTeO6:Dy3+ can be clearly reflected on different surfaces. In summary, NaMgLaTeO6:Dy3+ phosphor has proven high potential in w-LEDs production and LFP detection.

Design of flexible polyethylene glycol-based phase change materials by crystal structure regulation

The design of flexible phase change materials (FPCMs) with polyethylene glycol (PEG) as phase change components remains a great challenge due to high crystalline structure makes for high thermal energy storage ability yet deteriorates mechanical toughness. Herein, the preparation strategy of FPCMs was developed by introducing crystal structure regulators (CSRs) in PEG-based FPCM networks in a form of covalent linkages. The hydroquinone CSR had the strongest ability of crystal structure regulation over FPCMs compared to the three other used CSRs. The FPCMs had tuneable phase change temperatures (−2.0 °C–49.7 °C) and enthalpies (40.7 J g−1 to 109.3 J g−1) depending on the number-average molecular weight (Mn = 4000 Da, 6000 Da) of PEGs used as well as the content and type of CSRs, further enabling tuneable mechanical stress (0.59–15.61 MPa) and strain (5.74%–505.86 %). Compared with the pristine PEGs, the FPCMs yielded excellent shape stability, thermal stability and thermal reliability. The flexibility and phase change properties endowed the FPCMs with excellent self-adaptability and shape memory function. The innovative strategy towards FPCMs highlights the application potential on individual wearable temperature-controlled devices.

Effects of solutes and additives on ice growth prevention in ice slurry production

Ice slurry is a promising functional fluid with high thermal energy density and high heat transfer rate. However, large ice particles in the ice slurry can cause blocking of tubes during ice slurry flow. Therefore, it is preferable to use fine ice particles to prepare ice slurry in many fields. In this study, ice slurries were generated from supercooled solutions containing additives, such as anti-freeze protein and polyvinyl alcohol, to prevent the increase in the ice particle size in the formation process of the ice slurry. The concentration of the solute and amount of the additive were varied as experimental parameters, and the size of the ice particles was evaluated. The average area of the ice particles decreased with the addition of the additives. In particular, anti-freeze protein was effective for generating fine ice particles in the ice slurry. However, the effects of the additives became weaker for higher concentration of the solute, and the size of the ice particles was almost the same regardless of the concentration of the solute and the amount of the additive. Moreover, it was found that particular properties, such as the freezing-point depression, kinematic viscosity of the solution, and effective latent heat of fusion, did not affect the size of the ice particles in the ice slurry generation process.

Chemoexcited Formation and Radiationless Decay Dynamics of Firefly Chromophore.

Multistate nonadiabatic dynamics combined with Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory (MRSF-TDDFT) were performed to investigate the chemoexcitation dynamics of firefly dioxetanone (FDO- in S0) to oxyluciferin (OxyLH- in S1) and its subsequent decay dynamics. The formation of oxyluciferin occurs within approximately 100 fs and is primarily controlled by oscillatory CO2 decarboxylation. Unexpected radiationless decay from oxyluciferin was also observed, facilitated by intramolecular rotation. Simulations under three thermal conditions reveal that higher initial thermal energy not only enhances the formation of oxyluciferin but also increases radiationless decay by surpassing barriers to the ground state. Conversely, lower thermal energy conditions reduce oxyluciferin formation but suppress radiationless decay. These findings suggest that optimal conditions for higher chemiluminescence quantum yield involve initial high thermal energy to accelerate CO2 decarboxylation and gradual thermal dissipation to prevent intramolecular rotation of oxyluciferin. This approach could enhance the chemiluminescence quantum yield beyond the current limit of 40%, offering significant potential for applications in biological imaging and analytical chemistry.

Enhanced mechanical property, high-temperature oxidation and ablation resistance of carbon fiber/phenolic composites reinforced by attapulgite

To meet the thermal protection and load-bearing requirements of ultra-high-speed vehicles, it is urgent to improve the ablation resistance, high-temperature oxidation resistance and mechanical properties of carbon fiber/ boron phenolic resin (CF/BPR) composites simultaneously. Herein, polyhedral oligomeric silsesquioxane-modified attapulgite (ASP) with abundant porous structure was successfully introduced into the CF/BPR (CF/ASPBPR). The co-effect of ceramization, high infrared emissivity, and low thermal conductivity endowed the CF/ASPBPR with desirable ablation resistance, where the linear ablation rate and mass ablation rate reduced to 0.038 mm/s and 0.035 g/s, respectively. Meanwhile, due to the high thermal stability and energy dissipation of ASP, the CF/ASPBPR also presented the interlaminar shear strength of 35.40 and 9.79 MPa before and after high-temperature treatment, which were 24 % and 63 % higher than that of CF/BPR, respectively. This study provides a promising pathway for preparing advanced thermal protection materials that can adapt to severe mechanical spalling and thermochemical erosion environments.

Structural transition in the single layer growth of diindenoperylene on silica.

When forming a film on a substrate, rod shaped organic molecules can order in lying-down or standing-up phases. We have studied the growth of diindenoperylene films on amorphous silicon dioxide by means of molecular dynamics simulations and analyzed the film structure. The vapor deposition process was emulated by depositing single molecules at a fixed rate on the substrate. At 400K, we observed a transition from disordered lying-down to standing-up molecules, which agrees well with experimental observations. This transition, which depends sensitively on the kinetic parameters, requires both a sufficiently high thermal energy to overcome the energy barrier and a sufficiently large cluster size. Our results indicate that a higher degree of initial disorder in the lying-down phase results in a larger probability for the system to undergo the transition to the standing-up phase.

Heat release efficiency Betterment inside a novel-designed latent heat exchanger featuring arc-shaped fins and a rotational mechanism via numerical model and artificial neural network

Thermal energy storage (TES) units featuring phase change materials (PCMs) have a crucial impact on efficient energy management. Since energy demands keep changing, and the world increasingly relies on sustainable energy sources, innovation is continuously required. New technologies, materials, and methods for energy storage must be developed to meet these shifting needs effectively. In this study, a triplex-tube heat exchanger (TTHE) was employed as a TES medium, utilizing PCM within the middle tube. Because of its high thermal energy storage capacity, RT50 was selected as the PCM. Four innovative arc-shaped fins were strategically integrated within the PCM space to accelerate heat release. The system was subjected to rotational speeds of 0.1, 0.3, 0.5, 1, and 1.5 rpm. The investigation was carried out in two stages: initially, the impact of varying rotational speeds on the discharging process of the PCM in a finless TTHE was explored; subsequently, the influence of the same speeds on the solidification behavior of the finned TTHE was analyzed. Natural convection and PCM’s solidification process were examined through the enthalpy-porosity method. The findings represented that in the absence of fins, the device’s rotation had a more noticeable impact on the solidification behavior; however, incorporating fins was much more influential. Up to 2850 s, all the finned systems had solidified entirely in the presence or absence of the rotational mechanism, while in the finless system with a rotational speed of 1.5, 30.52 % of the material was still unsolidified until this time. Finally, the influence of three key structural parameters of the fins: α (outer fins arc angle), β (inner fins arc angle), and S (space between fins) on the discharging time of the PCM was analyzed using an artificial neural network (ANN) model. The study offered critical insights for optimizing fin configuration by systematically varying these parameters within defined ranges. An ANN predictive model was also proposed to assist TES system manufacturers and developers in future design and optimization efforts. The results demonstrated that the optimal setting of the TTHE (with the parameters of α = 60°, β = 60°, S = 10 mm) achieved the liquid fraction of 0.1, 80.33 % faster than the finless system.

Flexible loofah sponge-based phase change composite for thermal protection and wearable thermal management

To address the escalating demand for sophisticated thermal management in electronics, energy batteries, and wearable devices, extensive research has been dedicated to developing shape-stabilized and highly thermally conductive phase change composites (PCCs). However, their inherent rigidity and limited flexibility pose significant challenges for practical applications. In response, we have engineered a novel and flexible PCC by integrating loofah sponge (LS) and styrene-isoprene-styrene block copolymer (SIS) as co-supporting framework with paraffin wax (PW) as heat storage medium, further enhanced with carbon nanotubes (CNTs). The process began with the vacuum adsorption of PW into an ammonia-softened LS, which forming a fibrous network. This was followed by the introduction of a mixed melt of SIS and PW, physically cross-linked and dispersed with CNTs, into the LS fibrous network. The composite was then cooled and shaped to produce the (final) PCC. The resultant PCC exhibited remarkable ductility with an elongation of approximately 780 % and a maximum tensile strength of ∼2 MPa. Furthermore, it maintained thermal reliability and dimensional stability over long-term usage, with a melting heat enthalpy as high as 146.4 J/g. This flexible PCC, which combines high latent thermal energy storage, temperature regulation, and thermally induced assembly properties, shows considerable promise for thermal protection and portable thermal management in electronic devices.

Impact of high-temperature storage on capacity fading of Ni-rich cathodes in sulfide-based all-solid-state batteries

Despite the extensive research efforts focused on enhancing the lifespan and energy density of all-solid-state batteries, the calendar aging behavior of cathodes within the all-solid-state batteries system continues to be underexplored. In this study, we elucidate the capacity fading of Ni-rich cathodes in sulfide-based all-solid-state batteries after high-temperature storage using electrochemical techniques, synchrotron X-ray-based characterization tools, and electron microscopy. High-temperature storage negatively affects the electrochemical performance of Ni-rich cathodes, limiting their charge and discharge capacities, notably charge fading. The underlying cause of capacity fading lies in interfacial side reactions between Ni-rich cathode materials and solid electrolytes. The LiNbO3 coating layer is found to be effective in preventing interfacial degradation, which virtually eliminates charge and discharge fading. These findings offer a deeper understanding of the capacity fading of Ni-rich cathodes in sulfide-based all-solid-state battery systems during high-temperature storage. Furthermore, they provide insights for achieving all-solid-state batteries with high thermal durability and energy density.

Hydrophobic Multilayered PEG@PAN/MXene/PVDF@SiO2 Composite Film with Excellent Thermal Management and Electromagnetic Interference Shielding for Electronic Devices.

With the rapid development of electronic industry, it's pressing to develop multifunctional electromagnetic interference (EMI) shielding materials to ensure the stable operation of electronic devices. Herein, multilayered flexible PEG@PAN/MXene (Ti3C2Tx)/PVDF@SiO2 (PMF) composite film has been constructed from the level of microstructure design via coaxial electrospinning, coating spraying, and uniaxial electrospinning strategies. Benefiting from the effective encapsulation for PEG and high conductivity of MXene coating, PEG@PAN/MXene composite film with MXene coating loading density of 0.70mg cm-2 exhibits high thermal energy storage density of 120.77 J g-1 and great EMI shielding performance (EMI SE of 34.409dB and SSE of 49.086dB cm3 g-1) in X-band (8-12GHz). Therefore, this advanced composite film can not only help electronic devices prevent the influence of electromagnetic pollution in the X-band but also play an important role in electronic device thermal management. Additionally, the deposition of nano PVDF@SiO2 fibers (289±128nm) endowed the PMF composite film with great hydrophobic properties (water contact angle of 126.5°) to ensure the stable working of hydrophilic MXene coating, thereby breaks the limitation of humid application environments. The finding paves a new way for the development of novel multifunctional EMI shielding composite films for electronic devices.

Solar thermal energy and CO2 storage in saline aquifers for renewable energy space heating

There are a large number of abandoned oil and gas wells and corresponding depleted oil/gas reservoirs (DOGR) throughout the world, which are recognized as one of the best geological formations of saline aquifers for thermal energy storage and CO2 sequestration and however, the lack of innovative technique limits the efficient use of underground storage space. Here a novel scheme of storing solar thermal energy and concomitantly sequestrating CO2 in DOGR for renewable energy heating is proposed, which uses CO2 as thermal energy storage working fluid. The process of thermal energy storage and release as well as CO2 sequestration in DOGR are simulated, and thermal performance and CO2 dissolution in DOGR are analyzed. The results for twenty years of operation show that the thermal recovery efficiency reaches up to 82.93 %, which is 76 % higher than the traditional high temperature aquifer thermal energy storage. Energy storage capacity per heating season, energy storage density per unit volume of underground space and energy efficiency are respectively 57,222.27 GJ, 22,943.01 kJ/m3 and 96.19 %. Furthermore, the dissolved CO2 during thermal energy storage and extraction is 54.76 % larger than that of mere CO2 sequestration due to the repeated expansion and contraction of gas and water interface caused by the periodically injection and extraction of CO2, indicating that energy storage accelerates CO2 sequestration. To sum up, the new scheme is a high value-added technical route for solar thermal energy storage and CO2 sequestration as well as renewable energy heating.

Study on effects of anti-freeze protein and polyvinyl alcohol on the production and flow behavior of ice slurry

Ice slurry is a promising functional fluid with high thermal energy density and high heat transfer rate. However, the agglomeration of the ice particles in flowing ice slurry can cause blocking of tubes. In this study, anti-freeze protein (AFP) and polyvinyl alcohol (PVA) were selected as additives to prevent the agglomeration of ice particles in ice slurry. Ice slurry was generated using the release of the supercooled state of 3 mass% NaCl solution containing the additives. The size of the ice particles in the ice slurry was observed, and the average area of the ice particles was evaluated to reveal the effects of the additives on the ice particle size. Furthermore, the flow behavior of the ice slurry in a tube was observed, and the effects of the additives on the flow behavior and prevention of the agglomeration of the ice particles were evaluated experimentally. It was found that the average area decreased with increasing concentration of the additives, and the effect of AFP on the average area was particularly significant. In the case of without the additives, the ice particles flowed in the tube while the ice particles agglomerated. On the other hand, the ice particles in the ice slurry with the additives flowed without agglomeration in the tube, especially in the case of AFP addition. It was found that AFP prevented the agglomeration of the ice particles in the ice slurry flow. Moreover, the ice slurries with AFP show the significant tendency for pseudo-plastic fluid.