The immersion phase-change cooling technology utilizes the latent heat of the cooling liquid to dissipate heat by directly contacting the cooling liquid with the heat-generating electronic chip, which can meet the cooling requirements of current high heat flux density data centers. In this paper, the effect of different factors on the heat dissipation performance of immersion phase-change cooling technology was explored through numerical simulation. The results show that, under certain power conditions, the inlet temperature and flow rate of the cooling water in the condensation module, as well as the different arrangement of servers, have a significant impact on the heat dissipation performance of the entire system. The inlet water temperature mainly affects the chip temperature after stabilization. With the decrease in the inlet temperature, the chip surface temperature decreases significantly. The inlet water flow rate mainly affects the time required for the heat exchange to reach the desired temperature. With the increase in the inlet flow rate, the required cooling time is shortened. As the spacing between servers increases, the thermal safety and stability of the entire system increase. When the spacing between servers increases from 5 mm to 15 mm, the highest temperature and the temperature uniformity coefficient between the systems decrease significantly. When the spacing increases from 15 mm to 25 mm, the highest temperature and the temperature uniformity coefficient decrease slightly. These results can provide useful information for the designers of immersion phase-change cooling systems to improve the cooling efficiency of data centers, save energy, and ensure the safe operation of related computers, servers, and communication systems.

Low-temperature drying is becoming recognized as an optimal type of hot drying technology for agricultural and sideline products. This study presents an experimental study on drying roses with a heat pump dehumidifier. The rose drying process took 40 hours across three drying stages, where the hot air temperatures were 45°C, 50°C and 55°C respectively. The dried roses were brightly colored and good quality, also, rose water was obtained during the drying process when the waste heat was recovered. The major components of the rose water were rose ether, nerol, citronellol, acetic acid, phenylethyl alcohol, methyleugenol, and so on, which are typical compounds of rose essential oil. The results show that a heat pump is one of best choices for drying rose flowers, and that rose water can also be effectively recovered during the drying process.

Organic solvents with different volatilities are widely used in various processes and generate air and water pollution problems. One of the popular treatment processes for volatile organic compounds (VOCs) is regenerative thermal oxidation for the high destruction and removal efficiency. In this paper, the authors presents a project case dealing with VOCs, the waste gas with triethylamine and N-butylamine is disposed by a three-bed RTO treatment process. Two novel strategies were used in this project compared with the conventional RTO systems. Firstly, heat storage materials are saddle-shaped honeycomb, which could reform the distribution of waste gas flow in the saddle area and improve the efficiency of heat exchange. Secondly, the control mode of quick-opening valve is exhaust temperature control method instead of the time interval. The operation data shows that more than 99% of destruction and removal efficiency of VOC is obtained with slightly-level natural gas consumption. This research could provide a practical basis for the design of a RTO system.

The drying characteristics of bamboo shoot slices were experimentally studied in a hot air drying system. The individual and combined influence of air temperature, velocity, and slice thickness on the drying process was analyzed. The chromatic aberration and rehydration ratio were used as response indicators, and a 17-group experimental optimization of the drying process was carried out using a response surface methodology. According to the optimization analysis, a hot air temperature of 60.4 °C, an air velocity of 0.4 m/s, and a slice thickness of 0.2 cm were the optimal conditions for hot air drying of bamboo shoots. The predicted rehydration ratio and chromatic aberration of the dried bamboo shoot slices were 10.46 and 12.03, respectively. A validation experiment was conducted under optimum conditions to confirm the applicability of the models.

The problem of massive discharge of livestock wastewater is becoming more and more severe, causing irreversible damage to the ecological environment, and how to treat livestock wastewater efficiently and rapidly deserves to be studied in depth. In this work, CuO/granular activated carbon (GAC) loaded catalysts were prepared and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption/desorption techniques, and X-ray energy spectroscopy (EDS). The results showed that CuO was successfully attached to the GAC surface with good adsorption performance. The effects of catalyst dosage, H2O2 dosage, initial pH, microwave power and microwave irradiation time in different reaction systems on the degradation efficiency of chemical oxygen demand (COD) in wastewater were investigated, and the orthogonal experiments were used to explore the importance ranking of these factors. The highest degradation rate of COD was found to be enhanced by 12.1% in the reaction system of CuO/GAC, and the initial pH had the greatest effect on the COD removal rate. The combined MW/catalyst/H2O2 method used in this work provided a rapid and effective degradation of COD in wastewater, which can be helpful for reference in other microwave catalytic oxidation studies. [Graphics] .

Carbon dioxide (CO₂) capture and storage technologies are key methods for mitigating the greenhouse effect. The development of high-performance adsorbents using abundant natural minerals represents a promising approach to achieving cost-effective CO₂ capture. In this work, we report a simple and scalable strategy for preparing two-dimensional (2D) porous nanosheets from the natural layered clay mineral vermiculite as the raw material, via liquid-phase exfoliation and acid etching. The clay-based 2D porous nanosheets exhibited a high specific surface area, a hierarchical porous structure, and mechanical and chemical stability. In the presence of the 2D porous nanosheets, the CO₂ capture and adsorption capacity were significantly enhanced. The gas adsorption properties of the porous nanosheets were investigated over a wide temperature range (25–75 °C), achieving a gas uptake capacity of 38.22 mmol/g (at 75 °C and 35 bar). Furthermore, an intrinsic relationship between the pore structure of the porous nanosheets and their gas adsorption performance was revealed. The maximum uptake capacity remained at approximately 36.40 mmol/g during five adsorption–desorption cycles conducted at 75 °C. This work provides a promising approach for further development of clay-derived adsorbents for CO₂ capture and may also offer useful implications for understanding CO₂ geological sequestration.