Microporous metal materials have promising applications in the high-temperature industry for their high heat exchange efficiency. However, due to their complex internal structure, analyzing the heat transfer mechanisms presents a great challenge. This I confirm work introduces a mathematical model to accurately calculate the radiative thermal conductivity of microporous open-cell metal materials. The finite element and lattice Boltzmann methods were employed to calculate the thermal conduction and thermal radiation conductivities separately and validated for aluminum foams, with the relative errors all less than 9.3%. The results show that the thermal conductivity of microporous metal materials mainly increased with an increase in temperature and volume-specific surface area but decreased with an increase in porosity. Analysis of the spectral radiation characteristics shows that the surface plasmon polariton resonance and the magnetic polariton resonance appearing at the gas–solid interface of the metal foam significantly increase the dissipation effect of the gas–solid interface, further reducing the metal foam’s heat transfer efficiency. This indicates the potential of this work for use in the design of specific microporous metal materials like energy management devices or heat transfer exchangers in the aerospace industry.

As the integration of renewable energy sources continues to increase, thermal power units are increasingly required to enhance their operational flexibility to accommodate grid fluctuations. However, frequent load variations in conventional thermal power plants result in decreased efficiency, accelerated equipment wear, and high operational costs. In this context, molten-salt thermal energy storage (TES) has emerged as a promising solution due to its high specific heat capacity and thermal stability. By enabling the storage of surplus energy and its regulated release during peak demand periods, molten salt TES contributes to improved grid stability, reduced start-up frequency, and minimized operational disturbances. This study employs comprehensive thermodynamic simulations to investigate three representative schemes for heat storage and release. The results indicate that the dual steam extraction configuration (Scheme 3) offers the highest thermal storage capacity and peak-load regulation potential, albeit at the cost of increased heat consumption. Conversely, the single steam extraction configurations (Scheme 1 and 2) demonstrate improved thermal efficiency and reduced system complexity. Furthermore, Scheme 3, which involves extracting feedwater from the condenser outlet, provides enhanced operational flexibility but necessitates a higher initial investment. These findings offer critical insights into the optimal integration of molten-salt thermal-storage systems with conventional thermal power units. The outcomes not only highlight the trade-offs among different design strategies but also support the broader objective of enhancing the efficiency and adaptability of thermal power generation in a renewable-dominated energy landscape.

The closed mesoporous polymer gels have garnered significant attention as advanced thermal insulation materials due to their superior lightweight characteristics and excellent thermal management capabilities. To accurately predict their thermal performance, this study develops a novel mathematical model that integrates fractal geometry theory, Kirchhoff’s thermal conduction principles, comprehensive Rosseland diffusion approximation, and Mie scattering theory. The conductive thermal conductivity component was formulated based on a diagonal cross fractal structure, while the radiative component was derived considering microscale radiative effects. Model predictions exhibit strong agreement with experimental results from various mesoporous polymer gels, achieving a prediction error of less than 11.2%. Furthermore, a detailed parametric analysis was conducted, elucidating the influences of porosity, cell size, temperature, refractive index, and extinction coefficient. The findings identify a critical cell size range (1–100 µm) and porosity range (0.74–0.97) where minimum thermal conductivity occurs. This proposed modeling approach offers a robust and efficient theoretical tool for designing and optimizing the thermal insulation characteristics of closed mesoporous polymer gels, thereby advancing their application in diverse energy conversion and management systems.

Accurate thermal characterization of closed mesoporous metal gels is vital for high-temperature uses, yet microscale effects often ignored in macroscopic models significantly impact heat transfer. This study introduces a new predictive method based on an equivalent Voronoi model, accounting for the Knudsen effect and microscale electromagnetic interactions. Predicted thermal conductivity closely matched experimental results, with an average error of 5.35%. The results demonstrate that thermal conductivity decreases with porosity, increases with temperature, and varies with pore size, with a minimum of 17.47 W/(m·K) observed at ~1 μm. Variations in refractive index, extinction coefficient, and specific surface area exert negligible influence. Conductive heat transfer is suppressed under Knudsen-dominated conditions at small pore sizes. Electromagnetic analysis around the pore size corresponding to minimum conductivity reveals localized surface plasmon resonances and magnetic coupling at the gas–solid interface, which enhance radiative dissipation and further reduce thermal conductivity. Radiation dissipation efficiency increases with decreasing porosity and pore size. This model thus serves as a predictive tool for designing high-performance thermal insulation systems for elevated-temperature applications.

High-temperature radiative cooling is essential for solar absorbers, as it mitigates efficiency degradation resulting from thermal accumulation. While porous structures have proven effective in enhancing absorber performance, practical manufacturing processes and prolonged operational wear inevitably introduce surface roughness and structural deviations, which profoundly impact radiative properties. This study constructs a ZnS/Ag solar absorber model with surface roughness and employs the finite-difference time-domain method to investigate how characteristic length, surface roughness, porosity, pore shape factor, and taper influence its radiative properties in the 3 μm–5 μm band at 750 K. Results show optimal absorption at a 1 μm characteristic length with a 36.72% improvement compared to the model with l = 0.25 μm, increased absorption with higher porosity with a 69.29% improvement at 0.6 compared to the non-porous structure, lower circularity with a 19.03% improvement for C = 0.89 compared to C = 1.00, while surface roughness with a 61.24% improvement at RMS = 0.031 compared to RMS = 0 and taper with a 38.29% improvement at β = 20° compared to β = 0° also exert significant effects. This work provides engineering design guidelines for high-efficiency, low-cost absorbers.

Rapid charging and high-rate operation generate substantial heat in lithium-ion batteries, and insufficient heat dissipation can cause local heat accumulation and increase the risk of thermal failure. Macroporous metallic gels, represented by high-porosity open-cell metal foams, provide continuous heat transfer pathways and are promising media for battery thermal management. However, surface microdefects inevitably introduced during manufacturing and service can alter their thermal transport properties and consequently affect the accuracy of battery thermal safety prediction. In this study, open-cell aluminum and nickel macroporous metallic gels with spherical protrusions and depressions on the ligament surfaces were investigated. The effects of pore size (1–50 mm), contact angle (0–85°), defect volume fraction (0–10%), defect bottom radius (5–200 μm), and ambient temperature (300–400 K) on conductive, radiative, and total effective thermal conductivity were systematically investigated. The results show that increasing the protrusion content enhances heat conduction, whereas increasing the depression content significantly reduces the total effective thermal conductivity, with the maximum reduction approaching 90% when the defect content reaches 10%. Increasing the defect radius further strengthens the influence of depressions, particularly at smaller pore sizes. The calculated thermal conductivities of aluminum and nickel gels were applied to cylindrical and prismatic battery models to evaluate heating times from 300 to 350 K. Surface depressions slightly shortened the heating time, whereas protrusions generally prolonged it. The largest variation was observed, ranging from 153.415 to 153.500 s for cylindrical cells with nickel gels. These results provide a theoretical basis for defect-aware battery thermal management and safety prediction.