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This paper explores the potential of thermal storage as an energy storage technology with cost advantages. The study uses numerical simulations to investigate the impact of adding porous material to the HTF side during solidification to improve the heat transfer effect of TES using AlSi 12 alloy as the phase-change material. The research also examines the effects of adding porous dielectric materials and increasing air velocity on the discharge temperature, discharge power, and discharge time of high-temperature phase-change energy storage systems. The study found that the temperature difference of the PCM (increased), solidification time (reduced more than 85%), the outlet temperature of the air, and heat discharge power of the LHS did not vary significantly across different porous materials (copper foam, nickel foam, and silicon carbide foam) added to the HTF tube. These findings offer important information for the design of high-temperature phase-change energy storage devices and can guide future developments in this field. [ABSTRACT FROM AUTHOR]

This paper examines a Distributed Propulsion (DP) concept and involves CFD verification, optimisation and evaluation. The first part of the study validates the employed simulation methods using experimental data from the NASA Workshop for Integrated Propeller Prediction (WIPP) and the Folding Conformal High Lift Propeller (HLP) project, for isolated and installed cases under various conditions. Additionally, validation for rotor-rotor interactions was also conducted using the GARTEUR Action Group 26 measurements. The second part of the paper examines installed propeller configurations to identify performance differences based on their position relative to a lifting wing. The results indicate that distributed propellers with small radii interfere more with the wing, than tip-mounted, large propellers. Additionally, propeller and wing performance vary with respect to the propeller installation location. The propeller in tractor configuration showed higher efficiency than the over-the-wing (OTW) configuration by about 7%. However, results from this work showed a 2% improvement in the propeller efficiency when the OTW configuration had a pylon installed. This study also found that optimising the propeller from a tractor to OTW configuration, significantly improved the wing performance. At take-off and landing, the Lift-to-Drag (L/D) ratio of the OTW configuration almost quadrupled, and the overall propulsive efficiency increased by about 5%. The simulations showed that the OTW configuration with different numbers of propellers, outperformed the tractor configurations with the same number of propellers. Furthermore, up to 26% improvement in lift and overall propulsive efficiency was found by introducing the DP system in the OTW configuration. [ABSTRACT FROM AUTHOR]

Chloride molten salts are promising candidates for high temperature thermal storage applications, owing to their energy storage density and thermal stability. Nevertheless, the main disadvantage of them is their corrosive behaviour with metal containers, which narrows down the range of applications. Encapsulation is considered a favourable method to prevent the corrosion. In this work, composite thermal storage materials consist of a phase change material (PCM) and a encapsulation material are studied, where the PCM is a mixture of sodium and potassium eutectic salts and the encapsulation material is diatomite. The composite materials which consist of PCMs & encapsulation materials are fabricated using a micro encapsulation method which is a combination of mixing and sintering. After applying the aforementioned method, it is observed that the PCMs are distributed homogeneously in the composite materials. With the help of XRD, it is found that the compounds stay unchanged after the encapsulation process, which indicates that the materials are compatible to each other. In this study, the composite material containing 70 wt% PCM exhibits the most favourable thermal energy storage properties, stability and capsule integrity as it is shown that the latent heat of the aforementioned composite material is observed 179.3 J/g and no significant decline or salt leakage is found after hundreds of heating-cooling cycles. [ABSTRACT FROM AUTHOR]

We performed Molecular Dynamics (MD) simulations to study the mechanism of the specific heat enhancement in nitrate salt based nanofluids. 26.6% enhancement of specific heat capacity was observed by introducing nanoparticles into the salt system. Our simulations showed that the nanoparticles caused a layering effect in the adjacent region of the liquid molten salt. Hence we attribute the enhancement in the specific heat capacity of molten salts with the addition of nanoparticles to a previously undiscovered structural arrangement of salt atoms around the nanoparticles. [ABSTRACT FROM AUTHOR]

In this study, the effect of nanoparticle concentration was tested for both CuO and TiO2 in eutectic mixture of sodium and potassium nitrate. Results showed an enhancement in specific heat capacity (Cp) for both types of nanoparticles (+10.48% at 440 °C for 0.1 wt % CuO and +4.95% at 440 °C for 0.5 wt % TiO2) but the behavior toward a rise in concentration was different with CuO displaying its highest enhancement at the lowest concentration whilst TiO2 showed no concentration dependence for three of the four different concentrations tested. The production of cluster of nanoparticles was visible in CuO but not in TiO2. This formation of nanostructure in molten salt might promote the enhancement in Cp. However, the size and shape of these structures will most likely impact the energy density of the molten salt. [ABSTRACT FROM AUTHOR]

A fatty acid based phase change dispersion (PCD) for efficient high voltage electrical devices cooling has been developed and investigated in this paper. Experiments were firstly conducted to characterise the PCD thermophysical properties and to measure the bulk fluid and inner wall temperature of PCD flowing in a circular pipe by a self-designed rig. A 3D modelling based on the Euler-Euler model and homogenous single-phase model were then performed and validated through experiments, and further employed to evaluate the effects of particle size, concentration and operating conditions on flow characteristics, pressure drop, heat transfer and energy transport performance of the PCD. The results showed that both the particle size and concentration presented significant influences on heat transfer between the two phases, and average friction factor as well as heat transfer coefficient of the PCD. A higher averaged Nusselt number and a larger pressure drop were observed when the PCM particle diameter decreased to 7 μm. For the investigated conditions in this work, an optimal set of cooling performance for the developed fatty acid PCD was proposed and a PCM particle size of 7 μm under a flow velocity of 4 m/s and a concentration of 35% was recommended for industrial cooling applications. • Dielectric phase change dispersion designed for HVDC converter cooling developed. • 3D modelling based on Euler-Euler and homogenous models performed and compared. • Improved pressure drop and heat transfer correlations of PCD proposed. • The importance of averaging wall temperature along perimeter addressed. • Optimal PCD cooling condition based on overall performance evaluation given. [ABSTRACT FROM AUTHOR]

Summary: The paper concerns with a high performance cooling method for a HVDC converter using fatty acid ester‐based phase change dispersion (PCD) in a heat sink with double‐layer oblique‐crossed ribs. Thermo‐physical properties of PCDs were first characterized under both solid and liquid states, and the cooling performance of the heat exchanger was then experimentally examined, by heating two copper blocks clamped closely to the aluminium heating surfaces. A three‐dimensional Euler‐Euler multiphase approach was further performed to evaluate the thermal performance under different operating conditions including heating power, flowrate and PCD concentration. The results showed that the viscosity of PCD can be a 100 times that of water, but the increased pumping power was only ~17.01% on average. The use of the PCD achieved a lower temperature of heat sink and fluid than that of water under the same set of conditions due to the latent heat of the PCM, thus enabling a safer and cooler environment for temperature‐sensitive HVDC components such as insulated gate bipolar transistors (IGBT). An optimal set of working conditions was proposed and a flowrate of 8 L/min under a heating power of 1.1 kW and a PCM concentration of 25% was recommended for industrial cooling operations. Highlights: A novel cooling method for HVDC converter using a fatty acid based PCD presented.A 3D Euler‐Euler modelling performed and compared with experiments.Effects of operating conditions and PCM loading on cooling behaviour discussed.Three calculating methods of heat transfer coefficients compared.Optimal PCD cooling condition given based on overall performance evaluation. [ABSTRACT FROM AUTHOR]

Smoothed Particle Hydrodynamics is used to model natural convection and solidification of a liquid material inside a cylindrical pipe, whose wall temperature is kept below the freezing point. The model is validated with two benchmark cases and a parametric study targeting the properties of the most common phase-change materials is carried out. The results show three hydrodynamic regimes: the static regime, the dynamic regime, and the pseudo-static regime. In the static regime, viscous forces overcome buoyancy forces; liquid motion is minimal and the solidification front proceeds axisymmetrically from the wall to the centre of the pipe. In the dynamic regime, the flow shows the typical recirculation vortices of natural convection. Density differences drive the colder liquid in the lower (or higher, in the case of water) part of the pipe, where it quickly solidifies. Solidification does not proceed symmetrically and the solidified shell around the wall is thicker in the lower region of the pipe. The pseudo-static regime is the result of two competitive processes: on one hand a buoyancy-driven boundary layer tends to form around the solid-liquid interface, on the other hand the advancing solidification front tends to halt the motion by freezing the boundary. As a result, a small velocity profile around the solid-liquid interface is observed, but, as the solidification front moves, it has no time to transfer enough momentum to set the rest of the liquid in motion. A criterion for predicting the regime based on two dimensionless groups is given, and, since the regime affect the freezing time, a correlation for calculating the freezing time based on the hydrodynamic regime is provided. [ABSTRACT FROM AUTHOR]

Flow and heat transfer of aqueous based silica and alumina nanofluids in microchannels were experimentally investigated. The measured friction factors were higher than conventional model predictions at low Reynolds numbers particularly with high nanoparticle concentrations. A decrease in the friction factor was observed with increasing Reynolds number, possibly due to the augmentation of nanoparticle aggregate shape arising from fluid shear and alteration of local nanoparticle concentration and nanofluid viscosity. Augmentation of the silica nanoparticle morphology by fluid shear may also have affected the friction factor due to possible formation of a core/shell structure of the particles. Measured thermal conductivities of the silica nanofluids were in approximate agreement with the Maxwell-Crosser model, whereas the alumina nanofluids only showed slight enhancements. Enhanced convective heat transfer was observed for both nanofluids, relative to their base fluids (water), at low particle concentrations. Heat transfer enhancement increased with increasing Reynolds number and microchannel hydraulic diameter. However, the majority of experiments showed a larger increase in pumping power requirements relative to heat transfer enhancements, which may hinder the industrial uptake of the nanofluids, particularly in confined environments, such as Micro Electro-Mechanical Systems (MEMS). [ABSTRACT FROM AUTHOR]

This paper is focused on the characterisation and demonstration of Newtonian behaviour of salt at both high and low shear rate for sodium and potassium nitrate eutectic mixture (60/40) ranging from 250 °C to 500 °C. Analysis of published and experimental data was carried out to correlate all the numbers into one meaningful 4th order polynomial equation. Addition of a low amount of copper oxide nanoparticles to the mixture increased viscosity of 5.0%-18.0% compared to the latter equation. [ABSTRACT FROM AUTHOR]

In cold climates, heating the cabin of an electric vehicle (EV) consumes a large portion of battery stored energy. The use of battery as an energy source for heating significantly reduces driving range and battery life. Thermal energy storage (TES) provides a potential solution to the problem. Such a technology is also known as thermal batteries or heat batteries, which can store heat at a high energy density. Thermal energy storage is generally much cheaper with a longer cycle life than electrochemical batteries. Therefore, using thermal batteries with high energy storage density to provide heat for EVs in cold environments can reduce vehicle costs, increase driving range, and prolong battery life. This is especially so for large EVs with a high heat demand such as electric buses. This article examines the influence of temperature on EVs and heat demands of different EVs in low temperature environments. The heat storage concepts, devices and systems proposed and developed for EVs are then reviewed, and potential TES materials for different types of TES devices are discussed. Different TES technologies for EVs are compared and analysed. Finally, the advantages and disadvantages and applicable scenarios of different thermal batteries are discussed, and research gaps are identified for further research and development. • Different TES technologies for EVs are reviewed, compared and analysed. • Potential TES materials for different TES devices are reviewed and screened. • High-temperature metal phase change TES device has the highest energy density. • Thermal insulation is a limiting factor of high-temperature TES devices for EVs. • The application of thermal energy storage in electric buses has great potential. [ABSTRACT FROM AUTHOR]

[Display omitted] • Revealing and resolving the underlying cause of agglomeration in Ca(OH) 2 /CaO reaction. • Reduction of the CaO volume expansion from 250 % to at least 32 % via the Hollow microstructure. • Achieving a record-breaking energy density of around 1835 kJ/kg in Ca(OH) 2 /CaO scalable system. • Demonstrated Cyclability over 30 cycles with no damage to the hollow microstructure. • Doubling the kinetics of the Ca(OH)2/CaO reaction through the hollow microstructure. The Ca(OH)₂/CaO loop offers a promising solution for seasonal thermochemical heat storage, vital for decarbonizing the heating sector thanks to its high energy density and abundant raw materials. However, cyclic hydration/dehydration of limestone-derived CaO (r-CaO) faces challenges like agglomeration and high-volume expansion, limiting its expected performances. This study focuses on fabricating hollow CaO microspheres (h-CaO) with porous shells via a facile one-pot hydrothermal synthesis method, without doping materials. These microspheres exhibit superior cyclic performance compared to r-CaO, with SEM-EDS confirming successful fabrication. Over 30 cycles in the temperature range of 400–550 °C, h-CaO achieves an average storage density of 1755 kJ/kg, peaking at 1835 kJ/kg, with kinetics twice as high as r-CaO. Most importantly, the hollow microstructure reduces dramatically the apparent volumetric expansion from 250 % to as little as 32 %, offering a potential solution to agglomeration at the reactor level and advan44cing the commercial viability of the Ca(OH) 2 /CaO thermochemical storage technology. [ABSTRACT FROM AUTHOR]

• Properties of a phase change dispersion are experimentally determined • Phase change material in the dispersion was two fatty acid esters • Supercooling was reduced by 10 K using nucleating agents • Apparent specific heat of 8.5 kJ kg−1 K−1 over the temperature range 47.5–50.0 °C. Phase change dispersions have recently gained interest in isothermal cooling applications. So far, almost all of the investigated phase change dispersions consist of paraffins as the phase change materials. This paper presents a phase change dispersion with two fatty-acid esters as the phase change material, Crodatherm-53/Crodatherm-47 (50:50). The dispersion has a melting temperature of 50 °C and is foreseen in high-voltage direct current component cooling. The phase change dispersion was stabilised with emulsifiers to prevent phase separation and nucleation agents were added to supress supercooling. From thermal history calculations, the supercooling of the dispersion was reduced by 10 K with the addition of the nucleation agent. A monomodal particle size distribution was achieved. The viscosity of the dispersion at 20 wt.% and shear rate of 100 1s−1 was found to be 4.9 mPa۰s at 25 °C, and 2.0 mPa۰s at 60 °C.The viscosity at different temperatures, mass fractions and shear rates was also assessed. From DSC analysis, an apparent specific heat capacity of 8.5 kJ kg−1 K−1 was measured for the phase change dispersion. This value is double the apparent specific heat capacity of water within the desired melting range (47.5–50.0 °C). Thermal conductivity measurements showed in the emulsion form, at 25 °C the phase change dispersion had a thermal conductivity of 0.529 W m−1 K−1 and in suspension form at 60 °C was 0.561 W m−1 K−1. Both thermal conductivity values were lower than water at each temperature. [ABSTRACT FROM AUTHOR]

Summary This article reports a recent study on a liquid cooling‐based battery thermal management system (BTMS) with a composite phase change material (CPCM). Both copper foam and expanded graphite were considered as the structural materials for the CPCM. The thermal behaviour of a lithium‐ion battery was experimental investigated first under different charge/discharge rates. A two‐dimensional model was then developed to examine the performance of the BTMS. For the copper foam‐based CPCM modelling, an enthalpy‐porosity approach was applied. The numerical modelling aimed to study the impacts of CPCM types and inlet velocity of heat transfer fluid on both the maximum battery temperature and temperature distribution under different current rates. Dimensional analyses of the results were performed, leading to the establishment of relationships of the Nusselt numbers and dimensionless temperature against the Fourier and Stefan numbers. [ABSTRACT FROM AUTHOR]

• Compatibility of Solar Salt and four metal alloys for CSP plants is studied. • A static corrosion test at 500 °C and in air is performed. • The descaled and gravimetrical corrosion rate methods are compared and analysed. • An economical study assessing cost, mechanical properties and corrosion rate is done. • 304H and 316L have the best cost-corrosion rate-mechanical properties performance. One of the main limitations concerning the implementation of heat transfer fluids in Concentrated Solar Power (CSP) plants, are their compatibility with the construction material. Hence, the study of this interaction over cycles is crucial for a proper material selection and life span forecast. In this work, the chemical compatibility of four commonly used metals in CSP plants; low carbon steel-A1045, stainless steel-304H and 316L, and nickel alloy-Inconel 600, with one of the most promising HTFs, Solar Salt, was evaluated. Two different methodologies (gravimetrical and descaled method) were compared and used to characterise the corrosion behaviour depending on the metal coupons analysed, concluding that the best method for most of the metals is the descaled one. The corrosion oxides were also characterized using a combination of different techniques: SEM, EDX, and XRD. Inconel 600 showed the best corrosion resistance among the metals evaluated. However, a further brief economical study concludes that a compromise between the overall metal loss cost per year and the price of the construction material over the lifetime of the plant must be found. The two stainless steels (304H and 316L) were identified as the best performing according to metal loss vs. material price and mechanical properties vs. corrosion rate. [ABSTRACT FROM AUTHOR]

Thermophysical features of imidazolium ionic liquids and their defects regulations (supercooling and low enthalpy) as phase change materials are comprehensively reviewed. [Display omitted] • State-of-the-art review of imidazolium ionic liquids as multi-functional phase change materials presented. • Defects of supercooling and low enthalpy regulated by encapsulating ionic liquids in crystallization-promoting porous shell. • Thermophysical properties and latent energy storage capabilities of imidazolium ionic liquids described. • Effects of variation in cation chain length, anion, cooling rate and annealing temperature on phase transition discussed. • Applications of ionic liquids-based phase change materials summarized. This review aims to provide an insight into the imidazolium ionic liquids (ILs) as novel phase change materials (PCMs) for low and medium temperature thermal energy storage, with a focus on their multi-dimensional thermophysical/nucleation features within encapsulation for defect regulation during solid–liquid transition. Imidazolium ILs have been emerging as novel phase transition-based energy storage material due to unique properties of wide liquidous range, rich crystallization behavior, small thermal volumetric expansion and environmental-friendly properties, but suffer from defects of low enthalpy and large supercooling. To meet the challenge acting as PCMs, the work first gave a brief overview on supercooling regulation and enthalpy elevation of imidazolium ILs, and proposed micro-encapsulation with crystallization-promoting porous shell to regulate their defects. Then discussion regarding multi-dimensional thermophysical features of imidazolium ILs were given, including features within micro-confined capsule core (phase transition, melting point, thermal stability, specific heat capacity and thermal conductivity), nano-confined nucleation within the mesoporous shell, and mesoporous interfacial nucleation. Finally, the future applications of imidazolium ILs and microencapsulation in the fields of infrared stealthy, solar thermal utilization, thermal management in extreme environment and green energy-saving building were highlighted. The study provides a timely review of the imidazolium ILs acting as thermal energy storage (TES) materials, and future suggestion like functional ILs with more hydrogen bonds or supercooling utilization for seasonal TES may help concentrate efforts on solving the key issues in urgent need. [ABSTRACT FROM AUTHOR]

Highlights • New selection methodology for molten salt based nanofluids for CSP systems. • Nanoparticles in molten salt nitrates can increase energy density but also viscosity. • Specific heat capacity enhancement and viscosity increment is base fluid dependent. • Conflictive effects understanding assesses the suitable nanoparticle concentration. • Selection parameter shows if energy density enhancement overcomes pumping power. Abstract A high-performance heat transfer fluid (HTF) plays a crucial role in the overall performance and efficiency of concentrating solar power (CSP) systems for utilizing solar energy. Molten salt-based nanofluids, which may offer a promising solution to help reduce the size and cost of CSP systems, have attracted increasing attention. However, there is still no comprehensive assessment strategy that considers the conflictive effects of adding nanoparticles in HTFs, such as the compromise between energy storage capacity increase and pumping cost increase. In this work, a methodology for nanofluids screening and selection is proposed and a novel parameter (R) is determined to assess the conflictive effect. The parameter (R) considers the ratio between the relative pumping power and the relative energy stored of the nanofluid compared to its base fluid. Three promising eutectics nitrate based nanofluids (NaNO 3 –KNO 3 , LiNO 3 –NaNO 3 –KNO 3 , LiNO 3 –NaNO 3 –KNO 3 –Ca(NO 3) 2) doped with 0.5 wt.% and 1 wt.% silica nanoparticles were selected and evaluated by the proposed methodology. As a result, adding nanoparticles into binary salts always present a negative effect (R = 1.03–1.22) when considering the ratio between the relative pumping cost and the relative energy stored. For ternary salt, adding 1 wt.% silica nanoparticles would be more preferable with a decrease of the parameter (R = 0.89–0.97, R < 1). In terms of quaternary, adding nanoparticles into quaternary does not change the parameter significantly (R = 0.96–1.04). [ABSTRACT FROM AUTHOR]

Recently, corrosion of nanoparticles molten salt-based nanofluids studies have emerged as Concentrating Solar Power plants provide a low carbon alternative to produce electricity. Enhancing the heat capacity and thermal conductivity of molten salts by using inorganic nanoparticles has been targeted as a strategy to decrease the overall investment cost of CSP systems. However, there is scarce and insufficient information about their effect on the corrosion behaviour of nanofluids, whether the nanoparticle content increases it or have no significant effect. The scatter data found show no clear agreement and the measurements are done under different conditions (temperature, time, impurities, nanoparticle's chemical nature and concentration, metal and alloy composition, testing method). In this context, the authors evaluated the effect of SiO 2 nanoparticles concentration in an industrial-grade Solar Salt in contact with four different alloys; AISI 1045, 304H, 316L and Inconel 600 by isothermal tests, 500 °C up to 2160 h. The effect of nanoparticles, 0.5% and 1% wt., was evaluated in comparison with Solar Salt industrial grade. The corrosion rate of the samples decreased in the following order AISI 1045 > 304H > 316L > Inconel 600 and nanoparticles increased in general and to a different extent the corrosion rate of the alloys. The one that experiences the highest nanoparticle effect is stainless steel 304H, followed by AISI 1045 and Inconel. For 316L, no significant differences can be seen. The applicability assessment carried out has shown that molten salt nitrate-based nanofluids can be used with Inconel 600, 304H and 316L in long-term service high-temperature applications such as CSP. • SiO 2 nanoparticles affect the corrosion behaviour of molten salt nitrates. • Nanoparticles increase the corrosion rate of the studied alloys. • The increase of nanoparticles from 0.5 to 1 % wt. does not affect significantly corrosion. • 304H, 316L and Inconel 600 can be used for long-term service with 1 % wt. SiO 2 Solar Salt. [ABSTRACT FROM AUTHOR]

This work explores the use of sodium sulfate and diatomite to formulate composite materials for high temperature thermal energy storage applications. Sodium sulfate in the composite functions as a phase change material (PCM) and diatomite as a structural skeleton for shape stabilization. It is found that sodium sulfate and diatomite have an excellent chemical compatibility with the PCM melting temperature at around 880 °C. It is shown that the composite containing 45% diatomite gives an optimal formulation in terms of energy density, salt leakage and mechanical strength. The results also suggest that the composite with the optimal formulation has an application window of 890–980 °C. Failures occur to the composite materials at temperatures above 1000 °C. [ABSTRACT FROM AUTHOR]

The potential benefits of surfactant-conditioned sludge dewatering treatment with acid/alkali pretreatment were investigated in this study. The water content of dewatered sludge ( W) and specific resistance of filtration (SRF) were used to evaluate sludge dewaterability. Extracellular polymeric substance (EPS) content, bound water content, zeta potential, and rheological properties were measured to explain the change of dewaterability observed in the conditioning process. By introducing dodecyl dimethyl benzyl ammonium chloride (DDBAC), the EPS content of the sludge supernatant changed, and bound water content, charge strength, and apparent viscosity decreased simultaneously. Although DDBAC-conditioned sludge in strong alkaline had low bound water content, W and SRF increased rapidly because of the dramatically increasing of EPS in sludge supernatant. Remarkable decrement was observed in bound water content and W in DDBAC-conditioned sludge which was in weak acid environment for comparison. The results indicated that 75 mg/g of DDBAC at pH 4.84 was the optimum under which W and SRF were at their lowest point in sludge, 58.22 % and 0.521 × 10 m/kg, respectively. [ABSTRACT FROM AUTHOR]

• A 35kWh battery pack with a novel hybrid thermal management system is prototyped. • Phase change material is innovatively integrated with cooling plate. • The battery thermal management at the battery pack level and module level is studied. • Both cooling and thermal insulation performances are investigated. • Desirable control strategies are obtained for battery pack under 0.5C to 1.5C discharge rates. Controlling the temperature of a battery pack within an optimal range and ensuring uniform temperature distribution are the key to improving battery life. With the elevating energy density of batteries, more efficient and energy-saving thermal management system is urgently required for improving electric vehicle (EV) performance in terms of safety and long-term durability. In this work, a novel hybrid thermal management system towards a high-voltage battery pack for EVs is developed. Both passive and active components are integrated into the cooling plate to provide a synergistic function. A 35kWh battery pack incorporated with electrical, mechanical and thermal management components was designed, manufactured and integrated. As the core hardware, a pack-level cooling plate set was innovatively designed by integrating with phase change material (PCM). The results show that the combined passive and active cooling strategy ensured a desirable working temperature below 40˚C and a uniform heat distribution across the entire pack at discharging rates ranging from 0.5C to 1.5C under customized control strategies. Moreover, the cycling performance of air cooling and hybrid cooling, as well as the thermal insulation performance at both battery module level and pack level are compared, demonstrating the superior thermal management capability of the hybrid solution. [ABSTRACT FROM AUTHOR]

Phase change dispersions are useful for isothermal cooling applications. As a result of the phase changes that occur in PCDs, they are expected to have greater storage capacities than those of single-phase heat transfer fluids. However, for appropriate heat exchanger dimensions and geometries for use in phase change dispersions, knowledge about the convective heat transfer coefficients of phase change dispersions is necessary. A test unit for measuring the local heat transfer coefficients and Nusselt numbers of PCDs was created. The boundary condition of constant heat flux was chosen for testing, and the experimental heat transfer coefficients and Nusselt numbers for the investigated phase change dispersion were established. Different experimental parameters, such as the electrical wall heat input, Reynolds number, and mass flow rate, were varied during testing, and the results were compared to those of water tests. It was found that, due to the tendency of low-temperature increases in phase change dispersions, the driving temperature difference is greater than that of water. In addition, larger heat storage capacities were obtained for phase change dispersions than for water. Through this experimentation, it was acknowledged that future investigation into the optimised operating conditions must be performed. [ABSTRACT FROM AUTHOR]

A lithium-ion battery cell's electrochemical performance can be obtained through a series of standardized experiments, and the optimal operation and monitoring is performed when a model of the Li-ions is generated and adopted. With discrete-time parameter identification processes, the electrical circuit models (ECM) of the cells are derived. Over their wide range, the dual-polarization (DP) ECM is proposed to characterize two prismatic cells with different anode electrodes. In most of the studies on battery modeling, attention is paid to the accuracy comparison of the various ECMs, usually for a certain Li-ion, whereas the parameter identification methods of the ECMs are rarely compared. Hence in this work, three different approaches are performed for a certain temperature throughout the whole SoC range of the cells for two different load profiles, suitable for light- and heavy-duty electromotive applications. Analytical equations, least-square-based methods, and heuristic algorithms used for model parameterization are compared in terms of voltage accuracy, robustness, and computational time. The influence of the ECMs' parameter variation on the voltage root mean square error (RMSE) is assessed as well with impedance spectroscopy in terms of Ohmic, internal, and total resistance comparisons. Li-ion cells are thoroughly electrically characterized and the following conclusions are drawn: (1) All methods are suitable for the modeling, giving a good agreement with the experimental data with less than 3% max voltage relative error and 30 mV RMSE in most cases. (2) Particle swarm optimization (PSO) method is the best trade-off in terms of computational time, accuracy, and robustness. (3) Genetic algorithm (GA) lack of computational time compared to PSO and LS (4) The internal resistance behavior, investigated for the PSO, showed a positive correlation to the voltage error, depending on the chemistry and loading profile. [ABSTRACT FROM AUTHOR]