常减压加热炉的扩能优化

武汉石油化工厂常减压装置由2500kt/a扩能至3.500kt/a的改造中,加热炉部分针对存在的问题,对加热炉燃料、装置换热流程,燃烧器配置、余热回收系统、炉管系统、氧含量分析系统、吹灰系统等实施优化设计,实现了在不新建加热炉的情况下,满足装置扩能要求。     

Covalently cross-linked sulfonated poly(ether ether ketone)/tungstophosphoric acid composite membranes for water electrolysis application

Composite polymer electrolyte membranes consisting of covalently cross-linked sulfonated polyether ether ketone (SPEEK) with tungstophosphoric acid (TPA) are prepared and their electrochemical and mechanical properties are investigated with regards to application in water electrolysis. Covalently cross-linked membranes (CL-SPEEK) comprised of sulfochlorinated SPEEK membranes and SPEEK partially lithiated by LiCl, are prepared by reaction with 1,4-diiodobutane, and blended with TPA to avoid excessive water swelling and to reinforce their mechanical properties. These ion-exchange membranes show good electrochemical properties, including proton conductivity, ion exchange capacity (IEC), thermal stability, anti-oxidative stability, and satisfactory mechanical characteristics, such as tensile strength and elongation. In particular, among the TPA-composite membranes, the CL-SPEEK/TPA30 (30 wt.% TPA) membrane displays higher proton conductivity (0.128 S cm⁻¹) and tensile strength (75.01 MPa) than Nafion^® 117 at 80 °C. The ion-exchange membranes are used to construct membrane electrode assemblies (MEAs) of use in polymer electrolyte membrane electrolysis (PEME). The MEA are prepared using a non-equilibrium impregnation–reduction (I–R) method. The electrochemical surface area (ESA) and roughness factor of the MEA prepared with CL-SPEEK/TPA30 electrolyte measured by cyclic voltammetry are 25.11 m² g⁻¹ and 321.4 cm² Pt cm⁻², respectively. The prepared MEAs are used in the water-electrolysis unit cells. The cell voltage is 1.78 V at 1 A cm⁻² and 80 °C, with a platinum loading of 1.28 mg cm⁻². The results of the present study suggest that the good conductivity and mechanical properties of covalently CL-SPEEK/TPA composite membranes make them well suited for use in PEME.     

Experimental and numerical study of heat and moisture transfers by natural convection in a cavity filled with solid obstacles

Heat, moisture transfers and airflow by natural convection in a rectangular cavity containing on line cylinders were studied. The work zone was arranged in such a way that 2D transfer and flow were established. At steady state, temperature, velocity and humidity fields on the symmetry plane were measured in un-humidified and humidified cavity. These results were then used to compare with CFD simulation. The thermal stratification and circular air flow in the cavity was observed. Humidification at the bottom face of cavity contributes to increase air velocity. The influence of radiation near the cold and warm walls is significant.     

A model and heat transfer correlation for rooftop integrated photovoltaics with a passive air cooling channel

Photovoltaic (PV) panels can experience undesirably high temperatures due to the heat input by that part of the absorbed solar radiation which is not converted into electricity. Regulation of the temperature rise is necessary to maintain maximum solar to electric conversion. One approach for temperature regulation, suitable for rooftop integrated PV, involves fitting an open channel beneath the PV module. The panels are cooled by radiation and free convection as ambient air rises through the channel. A scale analysis and numerical study of PV modules with a back mounted air channel provides heat transfer rates over a practical range of operating conditions and channel geometries. A generalized correlation for the average channel Nusselt number for the combined convective-radiative cooling is developed for modified channel Rayleigh numbers from 10² to 10⁸, channel aspect ratios between 15 and 50 and inclination angles between 30° and 90°. The usefulness of a passive cooling channel to improve PV efficiency is illustrated by system analyses of typical PV modules.     

The rapid densification behavior of powder metallurgy Ti alloys by induction heating sintering

Micropores are decisive to mechanical properties and thermal deformation capabilities of powder met-allurgy(P/M)Ti alloys sintered compacts.As a result,achieving express densification is of prime im-portance and has attracted increasing attention recently.Induction heating owns the merits of high effi-ciency,short process,and low cost,and thus has huge potential to be used as a sintering approach for the fabrication of P/M Ti alloys.Nevertheless,the facilitated densification behavior associated with induction heating sintering remains unclear so far.To address it,powder metallurgy Ti6Al4V is manufactured via induction heating sintering with which the underlying sintering mechanism is investigated in-depth.It is found that induction heating could generate a fully densified compact in a remarkably shortened time,demonstrating its superior sintering efficiency as compared with conventional resistance furnace heat-ing.COMSOL finite element analysis reveals that the maximum current density during induction heating can reach 106 A m-2 though the magnetic field strength is solely 0.02 T,leading to a slight tempera-ture difference of approximately 30 ℃ between the interior and exterior of the billet.Furthermore,the rapid heating essentially starts at sharp corners of particles due to the potent current concentration ef-fect,which facilitates the cracking of the particle surface oxide film and thus enhances the direct contact between them.Moreover,the electromigration effect caused by induction current promotes the diffusion capability of elements,giving rise to expedited densification,alloying,and chemical homogenization.This work provides not only critical insight into the sintering mechanism of induction heating sintering but also significant guidance for low-cost powder metallurgy materials preparation.     

甲醇制烯烃(MTO)反应器分布管堵塞原因分析及措施

为解决反应器分布管堵塞导致分布管压差上涨问题,寻求解决方法.对影响反应器分布管堵塞的因素,如MTO装置急冷水、水洗水、浓缩水、废甲醇水、压缩机段间凝液等进行试验和对分布管堵塞原因进行分析.通过优化污水汽提塔操作,控制污水汽提塔塔顶出料冷后温度高于120℃,将污水汽提塔塔顶的低温冷却器切换至高温冷却器和控制较低的pH值(...