Search Results (4,083)

Under the background of the green transformation and energy conservation in the aviation field, hydrogen-fueled aero-engines are the primary direction for achieving sustainable aviation power development. However, the unique thermophysical properties of hydrogen fuel induce extreme thermal load challenges to engine thermal management. Based on the requirements of energy conservation and digital-intelligent technologies, this paper reviewed the recent research progress, important challenges, and future development directions in the thermal management field for hydrogen-fueled aero-engines, and filled the gaps in existing related reviews. (1) As for the liquid hydrogen thermal properties and thermal management requirements, the unique thermal physical properties of liquid hydrogen can easily cause fluctuations in heat load, large temperature differences, and material compatibility issues such as hydrogen embrittlement during storage, transportation, and combustion. The application of thermal barrier coatings, the design of targeted cooling structures, and the regulation of heat loss in the pipeline of the hydrogen supply system require particular attention. (2) As for the technical architecture and optimization of thermal management, the optimization of the high-pressure side manifolds in the cooled cooling air heat exchanger increases the flow uniformity by 18.8% and reduces the weight by 22.5%. The intercooled recuperated engine with the optimum area ratio reduces specific fuel consumption by 5.3% compared to the baseline engine in cruise. However, the system-level optimization research of the above widely recognized solutions is relatively limited in terms of coordinating the energy flow of engines. The baseline engine employed the method of system integration optimization to achieve a 2.99% increase in thrust and a 6.78% reduction in fuel consumption. (3) As for the thermal management modeling and simulation, the intelligent optimization method based on computational fluid dynamics reduces the pressure loss coefficient of the vane-integrated heat exchanger by 36%. Nevertheless, the multiphysics coupling model confronts a contradiction between computational cost and accuracy. (4) As for the comprehensive evaluation method, the advanced configuration of the hydrogen-fueled aero-engine can approximately reduce specific fuel consumption by 68.5% and NOx emission by 12.7% under the same maximum thrust condition. The hydrogen consumption of the proton exchange membrane fuel cells system model compared with the baseline system, optimized by the multi-objective optimization algorithm, has decreased by 15%, while the thermal uniformity has improved by 20–30%. However, the current evaluation system mostly focuses on a single dimension, lacking the analysis of nonlinear coupling among multiple factors and a closed-loop mechanism for evaluation, optimization, and verification. Future research should focus on the matching model of liquid hydrogen’s thermophysical properties and full flight conditions, global multi-energy flows optimization methods, multidimensional collaborative numerical simulation, multiphysics coupling models, and multidimensional comprehensive evaluation systems, to provide closed-loop theoretical support for the efficient, intelligent, and reliable thermal management system for hydrogen-fueled aero-engines. Full article

The integration of microencapsulated phase change materials (MPCMs) significantly improved the energy storage capacity of wood-based hybrid composites (WBHCs). MPCM incorporated into the surface coating enabled the composites to store thermal energy from solar radiation and ambient heat, offering an energy-efficient and sustainable solution for furniture applications. In this study, the structural, thermal, surface, and mechanical properties of MPCM/WBHC were comprehensively investigated. The microstructural features and chemical functionalities of the samples were characterized through scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Thermal performance and stability were subsequently assessed by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermal conductivity evaluation, and solar-based thermoregulation experiments. The MPCM exhibited onset melting and freezing temperatures of 25.72 °C and 21.73 °C, respectively, whereas these values ranged between 22.45 °C and 22.90 °C in MPCM/WBHC, indicating effective thermal integration. Thermoregulation results clearly demonstrated that MPCM substantially improved the thermal energy storage capacity of the composites. Overall, the findings highlight the strong potential of MPCM/WBHC as latent heat thermal energy storage material for energy-saving furniture and interior applications. Full article

This study presents the design and modeling of a first-of-its-kind experimental prototype integrating a high-temperature air-based Concentrated Solar Power (CSP) receiver with a diabatic Compressed Air Energy Storage (CAES) system. The prototype architecture and operating modes are defined, and a detailed thermal model of an Open Volumetric Air Receiver (OVAR) is developed and optimized, with emphasis on passive mass flow regulation under non-uniform solar flux. At nominal conditions (800 °C), the receiver achieves a predicted thermal efficiency of 81.6%. Transient simulations assess off-design dynamic behavior under realistic conditions, showing sensitivity to solar fluctuations and need for heliostat aiming strategies to reduce thermal non-uniformities and ensure stable outlet temperatures. For the CAES subsystem, a techno-economic analysis identifies high-pressure (300 bar) commercial gas cylinders as the most cost-effective aboveground storage solution, while discharge simulations yield a required storage volume of 4.8 m³. Finally, the complete piping and instrumentation diagram (P&ID) of the integrated system is presented, defining the experimental configuration. Overall, this work establishes the design basis for the future experimental demonstration of hybrid CAES-CSP operation for dispatchable renewable power generation and supports subsequent control development and scale-up analyses. Full article

Wastewater treatment plants (WWTPs) can serve as hubs for converting waste into energy, thereby supporting a city’s energy needs. Thermal processes, especially gasification, enable the transformation of sewage sludge into valuable products by producing energy-rich syngas for electricity generation. However, conventional air-based gasification introduces nitrogen as a diluent, reducing the syngas energy density. Integrating electrolyzers for hydrogen production into WWTP operations offers a strategic advantage: the oxygen co-produced during water electrolysis can be utilized as a gasification agent, thereby minimizing nitrogen dilution and enhancing syngas quality. The present work assesses the simulation of a conventional WWTP integrated with gasification and electrolysis systems using Superpro Designer V13. The results demonstrate that using pure oxygen in the gasification unit reduces the process’s thermal energy requirements and increases the syngas energy content by 5.5% when operating in a CO₂ atmosphere at an equivalence ratio (ER) of 0.15. The integration of anaerobic digestion and sludge gasification improves the overall energy balance by increasing electrical output (67%) and enabling thermal energy recovery, allowing sludge drying without auxiliary fuel. Water electrolysis is integrated as an energy storage system, allowing flexible operation during periods of excess renewable electricity. However, a simplified balance of this strategy reveals negative economic results unless electricity prices are below 7.5 c€/kwh. This approach underscores the need for further research into the use of reclaimed water for hydrogen production, as well as improving process integration to reduce the energy and water footprints of technologies supporting the green transition. Full article

Driven by the global low-carbon transition and the rapid expansion of marine energy development, offshore integrated energy systems are emerging as a critical configuration for coupling offshore renewable resources, geothermal and subsurface thermal resources, oil and gas infrastructure, hydrogen pathways, multi-carrier networks, and offshore loads. Unlike onshore integrated energy systems, offshore systems are constrained by resource intermittency, harsh marine environments, platform space and weight limits, long-distance transmission, operation and maintenance accessibility, safety risks, and cross-regional governance mechanisms. Recent studies have advanced offshore wind-to-hydrogen systems, oil and gas platform electrification, offshore energy hubs, platform repurposing, and offshore geothermal utilization. However, these studies remain fragmented in terms of system boundaries, multi-energy coupling mechanisms, engineering constraints, and optimization methods. This paper reviews offshore integrated energy systems from the perspectives of system configuration, key integration technologies, optimization and assessment methods, and future research needs. Offshore integrated energy systems are first classified into offshore renewable-energy-dominated systems, offshore wind–hydrogen systems, oil and gas platform integrated systems, offshore energy hubs and multi-carrier networks, decommissioned-platform repurposing systems, and offshore geothermal and repurposed-well systems. Resource-side, conversion-side, storage-side, network-side, and load-side integration technologies are then summarized. Capacity configuration, operational scheduling, stochastic and robust optimization, multi-objective optimization, energy, exergy, economic, and environmental (4E) assessment, advanced exergy analysis, and energy-hub modelling are further reviewed. Finally, key research gaps are identified, including resource uncertainty, offshore engineering constraints, multi-carrier network coupling, insufficient demonstration data, and policy and economic uncertainty. This review provides a structured reference for the modelling, integration, optimization, and demonstration of offshore integrated energy systems for low-carbon transition. Full article

In the context of the global transition towards energy systems with a high share of renewable energy, efficient and large-scale energy storage technologies are essential for improving the stability and flexibility of power grids. Phase change thermal energy storage has attracted considerable attention because of its high energy density and nearly isothermal heat release capability. However, its practical application remains constrained by the intrinsically low thermal conductivity of phase change materials (PCMs). For instance, 0.2–0.3 W/m·K for organic paraffins, 0.15–0.35 W/m·K for fatty acids, and 0.5–1.0 W/m·K for salt hydrates lead to slow charging and discharging rates. Incorporating metal foams into PCMs to form composite PCMs has emerged as a promising strategy, as metal foams can significantly improve effective thermal conductivity and enhance internal heat transfer. This paper systematically reviews recent advances in metal foam-enhanced phase change thermal energy storage, with particular emphasis on numerical modeling and structural optimization. First, the heat transfer enhancement mechanisms of metal foam/PCM composites are analyzed, together with the key performance indicators used to evaluate thermal storage performance. Second, material-level developments are reviewed, including pore structure parameters, interfacial engineering, and advanced fabrication methods. The review then discusses current structural design strategies, such as graded pore structures and partially filled configurations, as well as hybrid enhancement methods that combine passive and active heat transfer enhancement. Particular attention is paid to numerical modeling approaches at both pore and system scales, which are used to predict and optimize thermal behavior. In addition, optimization methods, including topology optimization, machine learning, and genetic algorithms, are examined for their potential to inversely design foam structures with tailored thermal performance. Finally, the key challenges in this field are summarized, and future research directions are proposed. These include multi-scale intelligent design, integration with complementary thermal management technologies, and the development of scalable solutions for engineering applications. This review aims to provide a systematic reference for achieving performance breakthroughs and promoting the practical deployment of phase change thermal energy storage technologies. Full article

Proton-exchange-membrane reversible fuel cells (rPEM) are emerging as key technologies for integrated hydrogen-based energy storage systems, enabling both electricity generation and hydrogen production within a single electrochemical device. However, the transition from laboratory-scale characterization to system-level deployment requires a consistent framework linking electrochemical modeling, parameter calibration, and system design. In this work, a semi-empirical electrochemical model of an rPEM cell is developed and calibrated against literature experimental data in both fuel cell (FC) and water electrolysis (WE) modes. The calibrated model achieves high predictive accuracy, with coefficients of determination exceeding 0.997. The validated model is subsequently extended to a preliminary system-level design, enabling the development of a 100 kW reversible PEM system coupled with a 300 kW electrolyzer configuration. The proposed system features symmetric hydrogen flow (6 kg h⁻¹), a 200 kWh hydrogen storage buffer, and operating conditions of 2.5 bar/70 °C in FC mode and 30 bar/65 °C in WE mode. Thermal effects and efficiency trends are analyzed, highlighting the critical role of heat management and balance of plant proposed design. The proposed methodology provides a consistent framework for scaling rPEM technology toward industrial applications. Full article

Two crucial yet opposing design criteria govern the performance of packed bed latent thermal energy storage systems (PBLTESS): energy storage capacity and thermal power. While the former depends on the packing density of the phase change material (PCM) capsules forming the packed bed, the latter is influenced by the surface-area-to-volume ratio (SVR) of these capsules. This study introduces novel superellipsoidal geometries for PCM capsules to address both these factors and quantifies the impact of design parameters on both mentioned performance criteria. First, by using discrete element method (DEM) simulations, we performed virtual bed filling experiments and generated packed beds from 116 superellipsoidal designs with similar volume. These simulations revealed a maximum packing density of 65.2%—significantly higher than conventional spherical capsule designs. Validation through bed filling experiments using 3D-printed superellipsoids confirmed the results of the DEM simulations, with an average deviation of less than 5%. Additionally, the SVR of each superellipsoidal design was determined through CAD analyses. Subsequently, six superellipsoidal designs as well as a spherical design were selected for further investigation using a 1D PBLTESS model to simulate charging and discharging. With up to 85% higher storage capacity (due to increased packing density) and up to 50% higher thermal power (resulting from enhanced heat transfer), the superellipsoidal geometries clearly outperformed the spherical design. Full article

Accurate estimation of insulation resistance, denoted as R_iso, in high-voltage direct current energy storage systems plays a pivotal role in leakage protection and thermal runaway suppression. Conventional physical measurement techniques are inherently susceptible to distortions under dynamic operating conditions due to interference from parasitic capacitance. Meanwhile, emerging data-driven approaches are often bottlenecked by cross-domain distribution shifts and the scarcity of annotated full-lifecycle data. This study proposes a hybrid framework that integrates transfer learning and residual correction within a CNN-LSTM architecture, referred to as TL-CNN-LSTM + Corr. Utilizing seven-dimensional operational features as inputs, the framework employs a one-dimensional convolutional neural network to extract high-frequency transient response patterns. Simultaneously, a long short-term memory network models the long-term, non-stationary temporal evolution of insulation degradation. To circumvent systemic biases across varying scenarios, a three-stage domain adaptation strategy consisting of pre-training, freezing, and fine-tuning was developed, which is complemented by a lightweight linear residual compensator designed to rectify amplitude drifts during abrupt operational transitions. Independent evaluations using 500 sets of real-world operational data demonstrate that the proposed model achieves high-precision predictions, yielding a root mean square error of 40.595, a mean absolute error of 32.919, and an R² value of 0.941. Furthermore, the model exhibits remarkable robustness against sensor noise and data loss. By ensuring cross-domain predictive consistency with minimal computational overhead, this framework provides a highly reliable and deployable solution for online insulation state monitoring in edge-side battery management systems. Full article

This study presents an ideal-cycle thermodynamic analysis of an advanced compressed air energy storage (A-CAES) system with single thermal energy storage (TES) and an external heat boost. The additional heat is represented by a solar heat source, although the analysis is equally applicable to other forms of externally supplied thermal energy. Following the classical thermodynamic approach used for ideal cycles such as the Brayton, Otto and Diesel cycles, the objective is to establish analytical relationships and performance bounds for the integrated system rather than to model a specific engineering configuration. Three principal performance measures are examined: the electrical round-trip coefficient of performance (CoP), the marginal thermal coefficient of performance associated with external heat addition, and the overall second-law efficiency. Closed-form analytical expressions are derived for these quantities under idealised but still practically relevant assumptions. The analysis identifies distinct operating regimes governed by the level of external heat input and establishes analytical transition conditions between them. It is shown that external heat addition can substantially increase the round-trip coefficient of performance and lead to high marginal heat-utilisation effectiveness. A rigorous upper bound on the second-law efficiency is also obtained from a complete-cycle exergy analysis, demonstrating consistency with the laws of thermodynamics. The results provide analytical insight into the fundamental thermodynamic structure of solar-assisted A-CAES systems and establish performance bounds that are independent of any particular engineering implementation. Full article

MXenes, a rapidly expanding family of two-dimensional transition-metal carbides and nitrides, are increasingly viewed as strong candidates for defense-oriented multifunctional systems because they combine metallic conductivity, surface tunability, mechanical flexibility, and solution processability within a lightweight platform. Unlike conventional metals, ceramics, and semiconductors, which usually optimize one or two parameters at the expense of density, brittleness, or integration compatibility, MXenes offer a rare opportunity to coordinate electromagnetic, mechanical, thermal, and sensing functions within one material family. Different from existing reviews that focus on laboratory-level record performance or single-function optimization, this review presents an innovative deployment-oriented perspective and fills the research gap of systematic military-oriented evaluation for MXenes. In this review, we examine MXenes from a deployment-oriented perspective rather than through isolated record values. We first summarize their formation chemistry and major synthesis routes, including HF and in-situ HF etching, bifluoride and alkaline methods, molten-salt strategies, electrochemical approaches, and precursor-free chemical vapor deposition. We then discuss the principal levers of property regulation, focusing on composition design, surface-termination control, and heterostructure engineering, and show how these strategies shape the performance envelopes relevant to shielding, stealth, impact response, energy storage, and sensing. This review constructs a full-chain analytical framework from synthesis, property regulation to military application and deployment challenges for the first time. Finally, we identify the main barriers to translation, especially manufacturing inconsistency, termination heterogeneity, oxidation and interfacial degradation, and limited application-level validation, and outline the most realistic paths toward deployable defense technologies. Full article

Edible and medicinal mushrooms, including cultivated and wild species, are increasingly recognized as valuable functional foods and nutraceutical resources due to their high nutritional value, abundance of bioactive compounds, and documented health-promoting properties. However, their high perishability results in substantial postharvest quality losses and limits commercial shelf life. This review provides a comprehensive overview of recent advances in mushroom preservation technologies, with particular emphasis on emerging non-thermal approaches such as cold plasma treatment, active packaging systems, and electrostatic field technologies. Conventional and advanced drying methods, edible coatings, biopreservation, fermentation and irradiation are also critically evaluated. Cold plasma treatment effectively reduces microbial contamination and enzymatic browning while maintaining firmness and nutritional quality, whereas active packaging systems based on chitosan films, nanocomposites, and modified atmospheres help reduce moisture loss, delay senescence, and preserve physicochemical properties during storage. Electrostatic field treatment combined with modified atmosphere packaging has shown additional potential for extending refrigerated shelf life. Among drying technologies, freeze-drying generally provides the highest retention of colour, texture and bioactive compounds, although its industrial application remains constrained by high energy consumption and operational costs. Overall, current evidence suggests that integrated preservation approaches offer the greatest potential for improving shelf-life extension and quality retention. Nevertheless, further research is required to address challenges related to industrial scalability, process standardization, economic feasibility and long-term quality assessment. Full article

Rock-bed thermal energy storage (RTES) systems are attracting growing interest as low-cost, robust, and scalable sensible heat storage solutions for applications ranging from low-temperature building and greenhouse heating to medium- and high-temperature solar or waste-heat recovery systems. However, their thermo-hydraulic performance is strongly influenced by the complex interactions among heat-transfer-fluid flow, irregular rock morphology, porosity, pressure drop, interphase heat transfer, and transient thermal-front development. This review provides a focused evaluation of computational fluid dynamics (CFD) modelling strategies for packed beds of rocks, with particular attention to continuum porous-medium approaches and the closure correlations required for reliable simulation. First, the distinction between pore-scale and volume-averaged continuum modelling is discussed in terms of the trade-off between physical resolution and computational feasibility. The main pressure-drop and friction-factor correlations are then reviewed and compared, including classical packed-bed models and rock-bed-specific formulations. It is shown that hydraulic-resistance predictions are highly sensitive to particle shape, surface roughness, porosity, the bed-to-particle diameter ratio, and packing arrangement. Particle-fluid heat-transfer correlations are also examined and, when possible, converted into a consistent particle Nusselt-number form to enable direct comparison. Particular attention is given to generalized correlations, dispersion-corrected models, and air–rock-bed correlations applicable to thermal storage systems. Finally, a methodological framework for modelling RTES systems using local thermal equilibrium (LTE) and local thermal non-equilibrium (LTNE) formulations is proposed. Dimensionless criteria, including the interphase thermal coupling number and particle Biot number, are introduced to support the selection between LTE and LTNE formulations. The selection of pressure-drop/friction-factor and solid–fluid heat-transfer/particle Nusselt-number correlations should be based on the similarity between the original experimental conditions and the target RTES system, and system-specific validation is recommended whenever possible. Full article

Lithium-ion batteries (LIBs) are widely used; however, they have safety hazards because of their susceptibility to thermal runaway (TR). Current early warning methods rely on the external monitoring of parameters such as temperature and strain. These methods have an inherent lag, as the signals can only be detected after internal heat and gas accumulation. Internal sensors are difficult to implement due to the harsh environment and high cost, leaving the ultra-early incubation stage of TR poorly addressed. To overcome these limitations, this study introduces acoustic emission (AE) technology for the real-time external detection of internal TR reactions. An experimental platform induced TR through overcharging, integrating multi-source AE and temperature signal acquisition. Continuous AE signals were collected from the onset of overcharging until the valve opened. Time–frequency analysis revealed anomalous waveform features in the early stage of TR; a two-dimensional method enhanced frequency-domain recognition. Combining the processed AE signals with a convolutional neural network achieved high-accuracy phase segmentation. Cross-validation and comparisons with temperature-based methods demonstrate the effectiveness and precision of AE monitoring for ultra-early TR warning. The results highlight the potential of AE-based monitoring as a proactive risk-management strategy, supporting dynamic assessment and safety responses in energy-storage applications. Full article

Silicon carbide (SiC) nanowires possess unique one-dimensional structural features, excellent mechanical strength, thermal stability and wide bandgap properties, showing great potential in high-temperature electronics, catalysis, sensing and composite reinforcement. Nevertheless, pristine SiC nanowires suffer from inert surface activity, weak interfacial compatibility and limited optoelectronic and catalytic performance. Surface coating and heterojunction engineering are effective strategies to address these deficiencies. This review systematically summarizes the synthesis routes of pristine SiC nanowires, including carbothermal reduction, chemical vapor deposition, template-assisted growth and molten salt synthesis, as well as their morphological regulation, physicochemical properties and inherent limitations. Meanwhile, typical coating methods such as wet chemical, hydrothermal, CVD and PIP are elaborated, and the influences of coating thickness, uniformity, adhesion and lattice/thermal compatibility on performance are summarized. The classification and interfacial charge mechanism of Type II, Z-scheme and Schottky heterojunctions are discussed, and the advances of coated SiC nanowires in photodetection, photocatalysis, gas sensing, electromagnetic shielding and energy storage are reviewed. Current challenges including coating stability, scalable preparation and integration bottlenecks are pointed out, and future research directions focusing on interface control, multifunctional integration and AI-assisted material design are prospected. Full article