Indoor environment quality is currently a hot research topic. In this study, composite air filter materials were synthesized using different impregnated porous medium materials, and their filtration performance and structural parameters were analyzed. The results showed that composite filter materials’ structures changed at the fibers’ surfaces when synthesized using different porous medium material layers. The filtration efficiency of composite filter materials synthesized using different porous media reached a maximum 0.8 m/s filtration velocity, and PM₁₀, PM_2.5, and PM_1.0 increased by 1.67~26.07, 1.19~26.96, and 1.10~21.98%, respectively. The filtration efficiencies of reduced graphene oxide composite for PM₁₀, PM_2.5, and PM_1.0 were 21.26, 20.22, and 18.50% higher, respectively, than those of carbon black composite. In addition, the filtration efficiency of the composite material synthesized by reducing graphene oxide improved for 0 to 1.0 μm particulates and was more effective by comparison. Filtration efficiency and resistance were comprehensively considered during air filter use to provide useful values for the selection and preparation of composite filter materials in the future.

A cascaded lattice Boltzmann (CLB) model is constructed for simulating heat transfer in metal-foam-based solid-liquid phase change materials (PCMs). The present model captures the phase interface implicitly via the enthalpy methodology, and to avoid iterations in simulations, the CLB equation of the PCM employs the enthalpy as the basic evolution variable through modifying the cascaded collision process. Numerical results demonstrate the effectiveness and practicability of the CLB model for investigating heat transfer in solid-liquid PCMs with metal foams. The effects of the inertial coefficient, permeability and porosity on the melting process are investigated. The results indicate that the empirical correlations of inertial coefficient and permeability based on packed beds overestimate the melting rate at high porosities. Moreover, the porosity has significant impact on phase-change processes. The melting rate increases as the porosity of the metal foam decreases since heat conduction through high thermal conductive metal foam dominates the total heat transfer.

Enhanced heat and mass transfer in a falling film liquid desiccant dehumidifier is crucial for improving the efficiency of liquid desiccant air conditioning systems. However, no study has yet been undertaken to examine the impact of a range of different enhancing elements on dehumidification performance. This study comprehensively investigates and compares falling film hydrodynamics and dehumidification performance on plates with various enhancing elements based on different air inlet velocity and humidity, solution inlet velocity, and concentration, as well as enhancing element spacing and height. The results demonstrate that, under a variety of working conditions, the dehumidification performance of the plate with isosceles right triangle shaped finned elements (plate No. 3) is superior to that of other plates. The dehumidification performance of plates with finned elements is superior to that of plates with grooved elements under the same condition. For plates with isosceles right triangle shaped finned elements, the impact of the flow field caused by the elements is greater than in other shapes due to the greater intensity of the gas-liquid perturbation and mixing, resulting in an enhanced dehumidification performance. The findings of this study may prove valuable in the optimization of dehumidifier structures in the context of liquid desiccant dehumidification performance enhancement.