In the field of ultrasonic enhanced heat transfer, the acoustic flow effect is the most common physical effect that enhances the heat transfer rate. This paper investigated the phase change heat storage process with enhanced acoustic flow effect under low sound power. First, the simulated work revealed the impacts of different acoustic vibration surface area on the phase change heat storage process under same sound power. The results show that the decreasing area of the acoustic vibration surface can improve the melting rate, which has the optimal value of the area. The general laws of forced convection and natural convection on promoting the melting process of phase change material (PCM) were further discussed. Then, the effectiveness and economy of the enhanced effect were quantitatively analyzed. The results indicate a strong correlation between the melting time of PCM and economy of the strengthening effect. Finally, the research further indicates that the acoustic flow effect not only promotes the melting of PCM, but also leads to the reduction of total heat storage. The significance of this study lies in providing a theoretical foundation for the development of new heat storage device.

A core-shell catalyst with ZSM-5 as the core and CeO2 as the shell was developed to address the poor sulfur tolerance of conventional Cu-based molecular sieve catalysts. The CeO2 shell was deposited onto the ZSM-5 surface using a wet chemical method. Active Cu species were then introduced via liquid-phase ion exchange, yielding the Cu/(ZSM-5@CeO2) core-shell catalyst. A genetic algorithm (GA) was applied to systematically optimize the catalyst composition. The optimal configuration was identified at a Cu loading of 2.92 wt% and a CeO2/ZSM-5 mass ratio of 0.13. Experimental results showed that the optimized catalyst exhibits excellent lowtemperature performance in the NH3-SCR reaction. Nearly 100% NO conversion was achieved over the temperature range of 225-500 degrees C, while N2 selectivity remained above 95%. X-ray photoelectron spectroscopy (XPS) analysis revealed that the CeO2 shell functioned as a sacrificial layer. It preferentially reacts with SO2 to form surface sulfates, thereby preventing SO2 from reaching the internal Cu active sites. This mechanism protects the core acidic sites and redox centers. Overall, the core-shell architecture significantly enhances sulfur resistance and promotes reactant adsorption and activation through shell-induced electronic effects. These findings offer new insights into the design of industrial flue-gas denitration catalysts.

In this work, molecular dynamics simulations were conducted to explore the effects of surface wettability and roughness on the bubble evolution characteristics during the ultrasonic cavitation process. In the calculation, the vibrating wall models with different wettabilities and varying roughness were constructed to reveal the cavitation process of water molecules under periodic ultrasonic excitation. The simulated results indicated that the hydrophobic surface facilitates the early formation of bubbles, but the hydrophilic wall contributes to the stabilization of bubble structures and their expansion into the bulk liquid. Meanwhile, the cavitation effect can be enhanced with the increasing roughness due to the generation of geometric traps. In addition, the geometric traps can promote the generation and persistence of bubbles near the boundary. Finally, the appearance, growth, and collapse of bubbles were related to the oscillation of pressure.

Comprehensive recovery of the valuable metals including scandium, nickel, cobalt, copper and zinc from laterite via a neutralization sludge produced in the hydrometallurgical process has been studied. The effect of solution equilibrium pH, temperature and reaction time on leaching performance has been investigated. The efficient recovery of scandium, nickel, cobalt, and copper from the sludge can be achieved by selective leaching using lowconcentration sulfuric acid solutions under mild conditions without use of other agents, or ore-pretreatments, and in turn, the co-leaching of impurities including iron and aluminum was low under optimal conditions. Pilot-plant tests were conducted under the optimized leaching parameters. The original sludge and the leaching residue were investigated by SEM-EDS and XRD analysis. More regular crystals were observed in the leached residue and a microstructure transformation mechanism was speculated during leaching. The scandium in the leaching solution was selectively recovered and separated from impurities by solvent extraction with a mixture of P204 and TBP extractants, and the valuable base metals including nickel, cobalt, copper, and zinc in the leaching liquors were further concentrated into mixed sulfides by sulfide precipitation. The developed process with leaching, solvent extraction and precipitation proves to be a promising route to produce several valuable metal products from the laterite sludge and help decrease the waste's environmental risk.

Municipal solid waste incineration fly ash (MSWIFA) is of great value in resource utilization. Harmless pretreatment is a crucial prerequisite for the resource utilization of MSWIFA. The detoxification process is a crucial step in the harmless pretreatment of MSWIFA. This includes polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), which are among the most toxic substances to humans and other living organisms. Low-temperature degradation technology has broad prospects in engineering applications due to the advantages of low technical difficulty and operating costs. This work conducts a pilot test on the degradation of 17 toxic PCDD/Fs in MSWIFA at low temperatures. The pilot test investigates the effects of reaction temperature and oxygen content on the degradation of PCDD/Fs in MSWIFA. Furthermore, based on the perspective of MSWIFA resource utilization, an analysis and a proposal are made to judge the degradation effect of low-temperature thermal treatment technology on PCDD/Fs in MSWIFA. Further, taking the soil sludge field as the application scenario, the application feasibility of MSWIFA after detoxification is analyzed. The flotation process markedly reduces both the carbon content and the levels of PCDD/Fs in MSWIFA. The hydrothermal method facilitates the degradation of dioxins in fly ash while introducing oxygen significantly lowers the reaction temperature required for fly ash treatment. This can enhance the degradation rate and reduce the demands on reaction equipment. The results indicate that the low-temperature thermal treatment technology can effectively degrade PCDD/Fs in MSWIFA, satisfying the requirements of some application scenarios. Notably, evaluating the effect of low-temperature thermal treatment technology on the degradation and detoxification of PCDD/Fs in MSWIFA should satisfy the residue requirements of different industries and achieve a certain detoxication efficiency.

The effective management of pollutants in waste incineration flue gas remains a critical challenge in environmental protection. This study develops a novel vanadium (V), molybdenum (Mo)/cerium (Ce), titanium (Ti)–polytetrafluoroethylene (VMo/CeTi-PTFE) composite catalytic filtration material to address the simultaneous removal of multiple pollutants in waste incineration flue gas purification. A systematic investigation of its performance and reaction mechanisms reveals that the coating process optimizes the pore structure of the filtration material. While the specific surface area is slightly reduced, the increased pore volume and diameter facilitate gas diffusion and enhance reaction efficiency. Experimental results demonstrate that under high catalyst loading conditions, this material exhibits outstanding performance in denitrification, dioxin degradation, and particulate removal, maintaining a consistently high dust removal efficiency of over 99.97%. Additionally, a high binder content enhances mechanical stability, while water and sulfur resistance tests confirm its exceptional durability. Mechanistic analysis indicates a significant synergistic effect between the denitrification reaction and dioxin degradation. Specifically, surface − OH groups promote the cleavage of C–Cl bonds, enabling efficient dioxin degradation while simultaneously improving nitrogen oxide (NOx) reduction efficiency and suppressing the formation of the byproduct nitrous oxide (N2O). This study provides a solid theoretical foundation and technical support for the design of multifunctional flue gas purification materials and underscores their broad application potential in managing complex pollutants. The findings have important implications for enhancing the efficiency and environmental benefits of waste incineration flue gas purification, representing a significant step toward more cost-effective, efficient, and environmentally friendly flue gas treatment solutions.

The ultrasonic wave could propagate in elastic media and bring ultrasonic flow which could effectively strengthen the convective heat transfer. Thus, various research works have been carried out on the enhancement effect for its potential future application. This work studied the influence of the acoustic flow effect on the melting process of phase change material. For the first, the influence of ultrasonic acting position on enhancement effect was examined. Then, the effectiveness of ultrasonic energy on enhancing heat storage process was discussed. The present work was also compared with other representative studies. The results show that when the side surface of the container is a constant temperature heating surface, the ultrasonic vibration surface at the bottom of the container has best melting performance of phase change heat storage. Then, a new evaluation method of heat transfer enhancement was proposed. The new method cannot only measure the improvement of melting performance, but also clearly measure the relationship between the improvement of melting performance and the consumption of ultrasonic energy. Finally, by contrast and analysis with representative studies, the development potential and further research direction of ultrasonic enhanced phase change heat storage are clarified. This work can provide reference for the further application of active heat transfer enhancement technology in the field of phase change heat storage.

Cavitation has been the subject of abundant studies, but the internal mechanism of cavitation is less well known. In this article, a microlevel near-wall model was established by using LAMMPS to present the process of cavitation effect. The results of molecular dynamics simulation revealed the fluctuation process of the liquid near the wall with the change in pressure. Molecular dynamics was also used to evaluate the void volume fraction and density distribution of the system. The results exhibited that the cavitation process can be divided into two stages: the initial cavitation stage and the rapid growth stage. Based on these results, the effects of wettability and initial system temperature on the near-wall cavitation effect were demonstrated. The results indicated that the hydrophobic near-wall forms a gas layer to weaken the density fluctuation, while the hydrophilic wall is opposite. Increasing the temperature could positively affect molecular motion and cavitation. This work provides a theoretical basis for further exploration of the cavitation effect.

采用加速寿命试验研究对比RuO2 IrO2/Ti及IrO2 Ta2 O5/Ti两种涂层电极的加速寿命,并研究了水中不同浓度氟离子对这两种电极加速寿命的影响.试验结果表明,IrO2 Ta2 O5/Ti电极的加速寿命约为RuO2 IrO2/Ti电极的加速寿命的40倍.水中氟离子对两种电极加速寿命有明显影响,当氟离子浓度为1 mg/L时,即可使RuO2 IrO2/Ti电极的加速寿命下降22％,使IrO2 Ta2 O5/Ti电极的加速寿命下降82％.氟离子具有很强的渗透性和腐蚀性,会使表面氧化物薄膜脱落,使钛基底暴露于电解液中被氧化成二氧化钛,导致电极完全失效.扫描电子显微镜、能谱分析结果表明,电极催化层中有效成分的溶解、电极催化层的开裂和剥落引起的钛基底暴露和氧化可能是导致电极失效的直接原因.

氢能是实现"双碳"达标的重要技术途径,但受限于电解水技术的经济瓶颈和储存运输的安全隐患,绿氢的工业化应用还未得到广泛普及.氨作为氢能载体的一种介质,是一种优质零碳燃料,具备还原剂的内在潜质,而且便于储存和运输,诸多学者已开展了氨能技术的研发工作.但将氨用作有色金属冶炼领域的能源供热和冶炼还原剂的应用或研究目前还处于空白阶段,本文基于氨的制备和储运、氨的燃料属性、氨的还原属性等分析,对铜、锌、铅、镍、锡、锑等 6 种常见的有色金属氧化物还原热力学进行了计算,结果表明,氨气还原的标准吉布斯自由能与碳还原的标准吉布斯自由能相接近,具备成为有色金属冶炼优质还原剂的条件;未来,还需要对氨气还原有色金属物料的还原动力学、气液界面反应强化机制、还原控速环节、还原动力学模型以及更深层次的还原机理等多项内容进行深入研究,以期为氨在有色金属冶炼领域的应用提供理论依据.另外,构建低成本绿氨供应链,开发具有自主知识产权的氨气零碳燃烧技术和氨冶金技术体系,将对我国冶炼工业低碳发展具有重要意义.

The preparation of spherical scandium oxide powders by ammonium bicarbonate precipitation was investigated. The carbonate containing scandium was prepared in the solution with ScCl (3)center dot XH2O as precursor. The effect of reaction temperature, amount of precipitant and stirring speed on the recovery of scandium was discussed. The effect of pH on the crystalline structure and particle size of carbonate containing scandium was characterized by the powder X-ray diffraction and laser particle sizer. Results demonstrate that the structure of carbonate containing scandium changes from non-crystalline structure to crystalline structure with increasing the reaction pH value. It indicates that when the initial change pH value is about 6, the crystalline structure of scandium oxide is cubic structure. Meanwhile, scandium sediment particles with 3.756.103.8 mu m in size can be obtained in a certain condition, depending on the pH value,. When the feasible pH value is 7, the D-50 of scandium sediment can be 6.634 mu m. The carbonate containing scandium is used as a precursor for the preparation of scandium oxide. The TG-DTA result indicates that the decomposition temperature of the carbonate tends to about 600 degrees C. Based on the XRD and IR analysis, it can be concluded that the appropriate calcination temperature for obtained relatively pure scandium oxide is 1000 degrees C. Meanwhile, the obtained scandium oxide powders were characterized by the laser particle size analyzer, BET and SEM-EDS. The crystallite size of spherical scandium oxide powders is less than 10 mu m with a surface area of about 373.952 m(2)/g. The microstructure is very homogeneous with spherical structure.

It is necessary to reveal the impact of nanoparticles on ultrasonic cavitation phenomena in nanofluids, which is conducive to the heterogeneous nucleation applications of ultrasonic cavitation. In this work, the ultrasonic cavitation processes in pure water and nanofluids were simulated by molecular dynamics. Then, the effect of nanoparticles on ultrasonic cavitation was investigated by adding alternate positive and negative pressure waves. After that, the formation of critical bubbles in cavitation and the collapse of nanobubbles by shock waves were studied by using Voronoi mosaic method and rigid body model, respectively. Finally, the regenerated nanobubbles were analyzed after the collapse of nanobubbles. The results show that the nanoparticles could promote the formation of nanobubbles, and consequently, the nano-jets and nanoparticles movement occur during the collapse of nano-bubbles. Additionally, more tiny cavities generated after the collapsing of nanobubbles and the number of nanobubbles during second cycle will be larger than that of the first cycle. As a result, some of these cavities promote the generation of multiple ultrasonic cavitation bubbles in the subsequent ultrasonic cycle. This leads to the chain reaction effect of ultrasonic cavitation phenomenon occurring in nanofluids.

With efficient heat dissipation capacity, the microchannel heat sink (MCHS) can be exploited and applied in the development of new energy technologies. With 2.8 MHz high-frequency ultrasonic, the flow and heat transfer performance in different kinds of microchannel was studied. These microchannels included rectangular straight microchannel, 90 degrees fan-shaped and triangular combined cavity microchannel and 90 degrees fan-shaped and triangular combined cavity circular fin microchannel. Furthermore, the comprehensive performance of the microchannel was analyzed and evaluated in detail from different aspects such as flow characteristics, heat transfer characteristics, field synergy and efficiency analysis. At the low Reynolds number, the acoustic streaming effect induced by ultrasonic could destroy the wall boundary layer and improve the heat transfer between the fluid and the wall. However, with the increase of Reynolds number, the flow velocity gradually dominated the heat transfer process. Meanwhile, the ultrasonic mainly acted on improving the synergy between the flow and temperature fields. Moreover, the combination of cavity structure and ultrasonic was conducive to increasing the action depth of acoustic wave in the fluid, which was much easier to induce the acoustic streaming effect. Thus, the effect of ultrasonic enhancement could be greatly strengthened. More importantly, the efficiency of using ultrasonic to enhance heat transfer was higher than that of pump power. This work can contribute to the mechanism and improve the efficiency of active and passive enhancement of microchannel heat transfer by using high-frequency ultrasonic.

To promote the goal of peak carbon dioxide emissions and carbon neutrality, low-energy consumption buildings require innovative technologies and efficient energy management. In this paper, the multi-objective optimization and the energy, exergy, economic and environmental (4E) analyses of the compression/ejection transcritical CO2 heat pump with latent thermal storage (TPE-LTES) system are conducted, and the influences of crucial parameters on the system performance are evaluated. The results show that the optimal comprehensive COP and annual hot water production (mDHW) of the TPE-LTES system are 3.59 and 3110 tons, respectively. Then, the comprehensive exergy efficiency of the TPE-LTES system owns 48.93 % higher than that of the heat pump unit. Furthermore, the optimal life-cycle cost (LCC) and life-cycle CO2 emissions (LCCE) of the TPE-LTES system are 708,073 CNY and 575,512.79 kg, respectively. Moreover, with constant discharge pressure, the evaporative superheat can be preferentially increased to reduce the system LCC and LCCE. Finally, the comprehensive COP and exergy efficiency of the system can be improved by increasing the inlet water temperature, while the increasing inlet water flow rate is the least desirable. This work is helpful to promote the research and application of latent heat storage unit integrated into air source heat pump.

钒氧化还原液流电池是一种安全、环保、稳定、寿命长的电化学储能设备,对绿电储能和双碳政策实施具有重要意义.本文首先介绍了钒液流电池结构与特点;然后详细综述了钒电池的应用情况以及钒电池中钒电解液、电极和隔膜的研究进展情况;随后对钒资源、全钒液流电池国家相关政策进行了简述,并对当前钒液流电池市场规模根据现有数据进行了估算.最后,总结钒电池技术与产业发展现状,并展望了未来重点研究方向.

本文对石膏的热分解行为进行了系统的热力学研究和试验基础研究,结果表明:进行石膏固-固碳热分解反应,当碳硫比为3时,石膏转化为CaS的转化率达到最大(81.33％),且反应产物中CaS含量为71.19％;进行石膏气-固热分解反应,当气体CO/(CO+CO2)浓度为50％时,石膏转化为CaS的转化率为91.80％,且反应产物中CaS含量为93.51％;CaS作为硫化剂进行造锍熔炼时,硫化剂利用率可达到74％以上.据此,本文提出石膏选择性还原硫化富集有价金属的造锍熔炼工艺路线,并明确石膏硫化反应的控制关键因素为CaS的转化率.该试验结论可为石膏造锍熔炼技术在有色冶炼领域的应用提供理论依据.

基于复合结构原则,构建ZSM-5分子筛与氧化铈的核壳结构催化剂,研究核壳结构对于NH3-SCR催化性能的影响,特别是抗水抗硫以及水热稳定性的探究.研究发现Cu/(ZSM-5@CeO2)核壳催化剂不仅表现出良好的NH3-SCR性能,还具有较好的SO2耐受性.结合系列表征分析发现核壳催化剂中铈与铜的协同作用能改善催化剂的脱硝性能,同时ZSM-5分子筛能提供大量的酸性位点,有利于NH3的吸附和转化.CeO2外壳不仅能够稳定铜离子的存在并减少CuOx团聚物的生成,还能产生更多的氧空穴及吸附氧物种,有利于改善低温段催化活性.此外,SO2耐受性试验也证明了 CeO2外壳可以有效抑制硝酸盐和硫酸铵类物质的形成,表现为较高的SO2耐受性.因此,核壳结构催化剂的构建对推动脱硝催化剂的市场化应用很有意义.

当前,我国以煤炭为主的火力发电为主要的能源供应方式,但煤炭资源使用存在资源不可再生、二氧化碳排放量大、环境污染严重等问题.固体氧化物燃料电池(SOFC)具有一次发电效率高、产物环境友好等优点,被公认为21世纪的革命性绿色能源技术之一.本文围绕SOFC系统未来主要发展方向,对SOFC系统中氧化锆基、氧化铈基、钙钛矿基电解质材料性能进行综述,指出基于钪资源的氧化锆基电解质材料是当下电解质材料产业化的优选路径.我国钪资源储量优势明显,钪资源供给能够保障燃料电池新能源产业链持续安全发展,因此,建议从国家层面加强资源供给链、制造产业加工链、产品应用链和回收链各环节的政策引导,做好顶层设计,加速钪基SOFC产业孕育,牢牢把握新一代能源产业变革浪潮.

高盐废水具有离子浓度高、硬度大、难处理等特点,是我国有色金属冶炼难降解废水,热浓缩多效蒸发等传统处理工艺存在易结垢、能耗高等典型问题.本文在梳理我国有色金属冶炼废热乏汽资源和高盐废水来源的基础上,介绍了利用冶炼厂废热资源耦合处理高盐废水的新型低温热浓缩工艺(ENFI-LTE)技术,列举了该技术处理高盐废水、集中洗钠废水和黑镍废水的工程化应用案例,并对其运行成本和碳减排指标进行计算.低温热浓缩技术以废热耦合治理废水,具有流程短、能耗低、不加软化剂、浓缩倍率高、产水水质好等特点,是一种节能、减排、降碳、高效的高盐废水处理技术.

随着我国经济的快速发展和城镇化水平的提高,垃圾焚烧逐渐成为城市生活垃圾无害化处理的主要方式,但产出的飞灰因具有较高的浸出毒性和重金属浓度而归为危险废物,因此,焚烧飞灰无害化、资源化成为社会焦点问题.本文论述了生活垃圾焚烧飞灰的来源、危害及产排现状,重点阐述了生活垃圾焚烧飞灰的无害化处置技术及资源化利用途径,涉及固化/稳定化技术、分离萃取技术、热处理技术和协同处置技术等,综合分析了各无害化处置方法的优缺点,并基于现有垃圾焚烧飞灰处置的问题提出多技术联用新工艺思路,形成一步解决主要问题,多种方法辅助和按次序分多步骤、逐步解决问题的两种组合工艺,并对飞灰无害化处理及资源化利用提出了建议和展望.