A Novel Close-loop Strategy for Integrating Process Operations of Fluidized Catalytic Cracking Unit with Production Planning Optimization

Production planning models generated by common modeling systems do not involve constraints for process operations, and a solution optimized by these models is called a quasi-optimal plan. The quasi-optimal plan cannot be executed in practice some time for no corresponding operating conditions. In order to determine a practi- cally feasible optimal plan and corresponding operating conditions of fluidized catalytic cracking unit （FCCU）, a novel close-loop integrated strategy, including determination of a quasi-optimal plan, search of operating conditions of FCCU and revision of the production planning model, was proposed in this article. In the strategy, a generalized genetic algorithm （GA） coupled with a sequential process simulator of FCCU was applied to search operating conditions implementing the quasi-optimal plan of FCCU and output the optimal individual in the GA search as a final genetic individual. When no corresponding operating conditions were found, the final genetic individual based correction （FGIC） method was presented to revise the production planning model, and then a new quasi-optimal production plan was determined. The above steps were repeated until a practically feasible optimal plan and corresponding operating conditions of FCCU were obtained. The close-loop integrated strategy was validated by two cases, and it was indicated that the strategy was efficient in determining a practically executed optimal plan and corresponding operating conditions of FCCU.

铁基催化剂强化臭氧氧化深度处理印染废水的中试研究

针对广西玉林某工业园区污水处理厂二级工艺处理后的印染废水,利用铁刨花原位改性制备的铁基催化剂进行催化臭氧氧化中试,考察催化臭氧氧化技术对印染废水COD和色度的处理效果。实验结果表明:在本研究所使用的催化臭氧氧化反应器和反应条件下,进水COD在40~60 mg·L^(-1)范围,色度在80~120度范围,pH在6~9的印染废水,经过该工艺的处理可使出水水质稳定达到《纺织染整行业回用水水质》(FZ/T 01107—2011)标准。当进水COD维持在40 mg·L^(-1)以下时,出水COD可降至30 mg·L^(-1)甚至20 mg·L^(-1)以下,出水水质满足《地表水环境质量标准》(GB 3838—2002)Ⅳ类水标准。水力停留时间对处理效果的影响呈正态分布,建议值为60 min。铁基催化剂的活性组分和“微通道”结构,有利于臭氧与催化组分的结合以及羟基自由基的释放与作用,从而提高了臭氧利用率,使O_(3)/ΔCOD的值基本控制在2以下。

一次强对流风暴过程的人工防雹作业雷达回波演变特性分析

本文利用北京、天津两部CINRAD/SA雷达观测资料,对2021年6月30日影响北京地区的一次强对流风暴过程中的A、B两个对流单体的人工影响天气作业雷达回波演变特性进行了分析。通过对统计区域内多种物理参数和不同高度层不同反射率强度档的格点数在单体发展各阶段及作业前后的变化分析,得到不同强度单体在不同作业情况的演变特性的认识。单体B为普通对流云团(生命期为3 h),在发展初期进行大剂量作业后(24分钟内有效作业火箭74发,高炮58发)可以看到有较好的抑制单体发展的特征,作业后一小时内,单体各高度层平均反射率、风暴体高度、垂直累积液态水等参数都呈下降趋势。较强回波(30~60 dBZ档区)格点数总体减少,较弱回波(20~30 dBZ档区)格点数快速增加,对流结构整体减弱。而单体A为超级单体(生命期为5.5 h),初生阶段由于作业剂量不足(30分钟内有效作业火箭15发),未见明显抑制效果。临近成熟阶段进行了连续大剂量作业(80分钟内有效作业火箭105发,高炮182发),虽然也能观测到类似B回波的一些特征,如,高层平均反射率、云顶高度、强回波厚度、垂直累积液态水等参数下降,较大反射率强度档区(50~70 dBZ档区)格点数减少,低层较小反射率强度档区(30~50 dBZ档区)格点数增多,并维持约30分钟的效果,但整体针对超级单体A的作业抑制效果不明显。

广东省一次飞机暖云催化响应的双偏振雷达观测分析

为研究飞机暖云焰剂催化后云系发生的物理响应,利用汕尾市双偏振雷达观测量及反演的云微物理特征参量,结合大气环境场探测数据,对2020年8月30日在广东省汕尾市北部区域实施的催化过程进行了分析,结果显示:这次过程是盛夏季节副高边缘的一次以暖云降水为主的对流性降水过程,天气尺度系统强迫较弱,大气层结不稳定,但水汽不充沛。在积云发展的暖云阶段引入吸湿性催化剂,16 min之后,暖云云系体积开始增加,差分反射率因子、差分相移率、雨水含量及降水强度的平均值都有明显增长,雨滴尺度增大、浓度明显增加,雨滴质量平均直径(D_(m))和表征雨滴数浓度的标准化参数(lgNW)增长幅度分别达到10.3%和39.5%,云系维持了大约1.5 h。吸湿性核先在催化层附近吸收水汽增长为数量众多的小云滴,与自然对流发展伴随的上升气流加强相互叠加,增强了云滴的碰并过程。众多小雨滴被上升气流带入0℃层之上使过冷雨滴短暂增多,促进了霰粒子的生成。

输电线路避雷器全生命周期状态在线监测方法

为降低因避雷器导致的电力事故发生概率、保证输电线路安全平稳地运行,以全生命周期为切入点,提出避雷器状态在线监测方法。针对氧化锌材质避雷器,分析设备全生命周期中各个阶段状态情况。然后针对泄漏电流与加载电压模拟信号实施快速傅里叶离散化处理,将信号从时域转换成频域,并获取阻性电流基波分量与奇次谐波分量,从而实现对避雷器状态在线监测。仿真实验环节主要检测监测免疫性,经电磁波干扰与表面温度等试验环节,验证该方法能够有效抑制电磁波与正常设备表面温度的负面影响,且实时性较好。

DCC装置长周期运行工艺核算及技术分析

中海油东方石化有限责任公司(简称东方石化)增强型催化裂解(DCC-plus)装置的第二个生产运行周期内,装置原料性质变化频繁、操作工况调整较大,基于原料性质和催化剂性质,通过定期开展工艺核算及技术分析,调控原料预热温度、蒸汽注入量、反应苛刻度、重点部位线速,稳定油浆系统操作参数,优化设备管理等,确保该装置在第二运行周期内未发生非计划停工情况,并成功实现了DCC-plus装置检修周期由3年延长至4年的突破。

恒温雷火灸联合生物刺激反馈仪在预防宫颈癌根治术后尿潴留中的应用分析

目的 探讨恒温雷火灸联合生物刺激反馈仪在预防宫颈癌根治术后尿潴留中的应用效果。方法 选取90例宫颈癌根治术患者,采用随机数字表法分为对照组30例、生物刺激组31例、联合组29例。对照组采用常规照护,生物刺激组在对照组基础上采用生物刺激反馈仪训练,联合组在生物刺激组基础上联合恒温雷火灸治疗。比较三组患者干预后尿潴留发生率、膀胱功能恢复情况、生物刺激反馈仪评分。结果 联合组患者尿潴留发生率均低于生物刺激组和对照组(P<0.05),生物刺激组患者尿潴留发生率低于对照组(P<0.05);联合组患者膀胱功能恢复情况均优于生物刺激组和对照组(P<0.05),生物刺激组患者膀胱功能恢复情况优于对照组(P<0.05);联合组患者生物刺激反馈仪评分高于生物刺激组(P<0.05)。结论 恒温雷火灸联合生物刺激反馈仪能有效预防宫颈癌根治术后患者尿潴留发生。

随桥电缆-架空混合线路的电缆护套过电压特性仿真分析

随桥电缆作为跨海输电系统的重要组成部分,其安全稳定运行对于整个输电系统的可靠性有重要影响。论文以舟岱大桥220 kV随桥电缆工程为研究对象,考虑架空线路的影响,基于PSCAD/EMTDC暂态仿真软件建立了随桥电缆-架空混合线路的仿真模型,对雷击故障和操作故障下的电缆护套过电压特性进行了研究。结果表明:雷击架空线路时,护套过电压幅值随故障距离的减小而增大,随杆塔接地电阻的增大而增大,过电压幅值最高可达到46.4 kV;单相接地故障下,接地相角为90°时护套过电压最严重,过电压幅值最高可达到15.9 kV;非全相操作故障下,电缆护套过电压幅值受故障距离的影响不大,两相断线的护套过电压比单相断线更严重。研究工作为随桥电缆-架空混合线路的绝缘配合设计提供了参考依据。

Cu/AC催化湿式氧化降解苯酚废水性能研究

以前驱体浸渍法制备铜基碳材料(Cu/AC)为催化剂,考察固定床反应器中不同操作条件对催化湿式氧化(CWAO)降解苯酚性能的影响。利用N_(2)-吸附脱附、XRD、XPS、热重技术,对反应前后Cu/AC结构进行表征,探究Cu/AC失活原因。结果表明,Cu/AC催化CWAO反应的最优操作条件为反应温度180℃,反应压力3.0 MPa,液时空速15 mL(g·h),气时空速4.5 L/(g·h),在反应5 h时苯酚、化学需氧量(COD)转化率分别达到97.0%、89.4%。Cu/AC催化剂失活的原因主要为Cu组分流失和表面沉积物的生成。反应过程中,Cu^(+)和Cu^(0)被氧化为更易流失的Cu^(2+),导致Cu组分流失,降低催化活性;此外,部分中间产物沉积在Cu/AC表面,造成催化剂孔道堵塞,暴露的活性位点减少,使得催化活性进一步降低。

复杂工况烟气氮氧化物催化净化

氮氧化物作为主要的大气污染物之一,对人类健康和大气环境造成严重危害。近年来,我国电力行业持续减少烟气中的氮氧化物排放,非电行业和新兴发电行业如垃圾焚烧/生物质燃烧发电等领域的烟气氮氧化物污染控制成为固定源烟气减排的重点。目前,氨法选择性催化还原是应用最广泛且最有效的烟气氮氧化物净化技术。然而,非电行业和新兴发电行业烟气氮氧化物净化工况条件十分复杂,烟气中通常存在大量酸性气体(SO_(2)、HCl)、碱/碱土金属(Na、K、Ca)、重金属(Pb、Cd、As)和磷化合物等毒物,极易导致催化剂中毒失活。为了解决在复杂工况烟气中氮氧化物净化催化剂失活的问题,研究人员对催化剂的抑制中毒作用进行了广泛且系统的研究,包括提高催化剂对SO_(2)的耐受性、改善对碱金属和碱土金属的抗性,以及提升复杂工况烟气条件下的复合中毒抗性。综述了复杂工况烟气氮氧化物催化净化技术的研究进展,总结了催化剂抑制SO_(2)中毒、抑制碱/碱土金属中毒以及抑制复合中毒的有效策略,为开发高效、稳定且抑制中毒的烟气氮氧化物净化催化剂提供了参考和思路,同时也为推进氮氧化物净化催化剂在非电行业和新兴发电行业的复杂工况烟气净化中的实际应用提供了理论指导。

掺炼减压渣油对催化装置长周期运行的影响及应对

为拓宽催化裂解装置原料馏分,自2023年12月起,某石化2.2 Mt/a催化裂解装置原料由常压渣油和加氢尾油混合进料调整为减压渣油和加氢尾油混合进料。考虑到减压渣油中残炭、重金属、黏度等指标对催化裂解装置的长周期运行存在不利的影响。针对以上问题,文章分析掺炼减压渣油前后混合原料主要指标的变化趋势,并通过工艺调整减轻掺炼减压渣油对催化装置长周期运行的不利影响。

新型低压配电用复合型SPD的设计

针对压敏电阻(MOV,电压限制型元件)与陶瓷气体放电管(GDT,电压开关型元件)串联组成的复合型电涌保护器(SPD)的设计问题进行研究,并对GDT进行创新设计。对此类常规复合型SPD的设计方案进行研究,发现其无法兼具残压低、工作电压高的电气性能。通过独特创新的触发电路设计了创新型GDT,形成的串联复合型SPD兼具残压低、工作电压高的电气性能优势。针对“应用于未来各种高工作电压,低残压要求的SPD设计”需求,提供了一种有效、全新的设计理念。

安全高效的带电更换防雷绝缘子的防护工具设计

目前配电网10 kV线路大量使用防雷绝缘子,为提高供电可靠性,需带电进行防雷绝缘子的更换。为此,设计了封闭式的硬质绝缘遮蔽罩对防雷绝缘子进行绝缘遮蔽,保证安全性;采用绝缘操作杆实现绝缘遮蔽罩的快速安装。通过绝缘屏蔽罩和绝缘操作杆的协调配合,所设计的防护工具可有效提高防雷绝缘子更换带电作业的安全水平和工作效率。

Catalytic bed slenderness ratio and ADN/methanol ratio for decomposition and combustion characteristics within ammonium dinitramide(ADN)-based green aerospace thruster

The decomposition and combustion characteristics of ammonium dinitramide (ADN) based non-toxic aerospace propellant are analytically studied to determine the effects of catalytic bed structure (slenderness ratio) and operation parameters (mass fraction ratio of ADN/CH3OH) on the general performance within the ADN-based thruster. In the present research, the non-equilibrium temperature model is utilized to describe the heat transfer characteristics between the fluid phase and solid phase in the fixed bed. We determined the fluid resistance characteristics in the catalytic bed by experiments involving the method of pressure-mass. We have done the simulation study based on the available results in the literature and found the complex physical and chemical processes within the ADN thruster. Furthermore, an optimized catalytic bed slenderness ratio was observed w让h a value of 1.75 and the mass fraction ratio of 5.73 significantly influenced the propellant performance. These results could serve as a reference to explore the combustion characteristics within the thruster and the preparation of future propellants.

Influence of Design Margin on Operation Optimization and Control Performance of Chemical Processes

Operation optimization is an effective method to explore potential economic benefits for existing plants. The m.aximum potential benefit from operationoptimization is determined by the distances between current operating point and process constraints, which is related to the margins of design variables. Because of various ciisturbances in chemical processes, some distances must be reserved for fluctuations of process variables and the optimum operating point is not on some process constraints. Thus the benefit of steady-state optimization can not be fully achied（ed while that of dynamic optimization can be really achieved. In this study, the steady-state optimizationand dynamic optimization are used, and the potential benefit-is divided into achievable benefit for profit and unachievable benefit for control. The fluid catalytic cracking unit （FCCU） is used for case study. With the analysis on how the margins of design variables influence the economic benefit and control performance, the bottlenecks of process design are found and appropriate control structure can be selected.

Research on Evaluating Index of Lightning Protection Safety Performance of High Voltage Overhead Transmission Line

In order to improve the lightning protection performance of transmission lines, lightning protection management has been divided into every tower that lightning protection performance has been evaluated respectively. According to factors such as landform, span, tower type, grounding resistance, isolator type, and so on, relative ratio of tripping operation of every tower in the line has been calculated to evaluate its lightning protection safety performance, it is beneficial to operation maintenance and lightning reconstruction of transmission lines.

Separation process study of liquid phase catalytic exchange reaction based on the Pt/C/PTFE catalysts

The liquid phase catalytic exchange(LPCE) reaction is an effective process for heavy water detritiation and production of deuterium-depleted potable water. In the current study, hydrophobic carbon-supported platinum catalysts(Pt/C/PTFE) with high efficiency as reported previously for LPCE were prepared and comprehensive performance evaluation method is applied to evaluate the separation behaviors of LPCE systematically. Experimental results indicate that the optimum reaction temperature of 60–80℃ and the molar feed ratio G/L of 1.5–2.5 would lead to higher separation efficiencies. As to the packing method, a random packing mode with a packing ratio of hydrophobic catalysts 0.25 is recommended. In addition, thermodynamic analysis corresponds well with experimental results under lower temperature and G/L, while the suppression of kinetic factors should not be neglected when T > 80℃ and G/L > 1.5.

Synthesis,characterization and catalytic performance of nanosized iron-cobalt catalysts for light olefins production

Nanosized Fe-Co catalysts were prepared by co-precipitation method and studied for the conversion of synthesis gas to light olefins.In particular,the effects of a range of preparation variables such as Co/Fe molar ratios of the precipitation solution,pH value of precipitate,temperature of precipitation,promoters and loading of optimum promoter on the structure and catalytic performance are investigated.The optimal nano catalyst for light olefins （C2-C4） production was obtained over the catalyst with Co/Fe molar ratio of 3/1 which promoted with 2 wt% K.The results show that the best operational conditions were GHSV=2200 h^-1 （H2/CO=2/1） at 260℃ under atmospheric pressure.Characterization of catalysts were carried out using X-ray diffraction （XRD）,thermal gravimetric analysis （TGA）,differential scanning calorimetry （DSC）,scanning electron microscopy （SEM）,transmission electron microscopy （TEM） and N2 physisorption measurements such as Brunauer-Emmett-Teller （BET） and Barrett-Joyner-Halenda （BJH） methods.

Effects of Operating Conditions on the Catalytic Performance of HZSM-5 Zeolites in n-Pentane Cracking

In this work,n-pentane catalytic cracking over HZSM-5 zeolites was studied at 650°C under atmosphere pressure.A particular attention was paid to the measurement of n-pentane conversion,light olefins production,product distribution,coke deposit,etc.Several indexes were defined to evaluate the effects of operating conditions on the catalytic performance of HZSM-5 zeolites.It was found that decreasing the weight hourly space velocity,increasing the reactant partial pressure,and increasing the carrier gas flow rate could inhibit C-H bond breaking and enhance the C-C bond breaking and hydride transfer reactions,leading to reduced alkenes selectivity,which suppressed the formation of external coke and alleviated the deactivation of HZSM-5 zeolites.It was deduced that the catalytic stability of HZSM-5 zeolites was improved at the cost of alkenes selectivity.Compared with decreasing the weight hourly space velocity and increasing the reactant partial pressure,increasing the carrier gas flow rate could enhance the diffusion process and protect alkenes from being consumed in coke formation in order to improve the catalytic stability of HZSM-5 zeolites with less reduction of alkenes selectivity.

Analysis of Airplane Precipitation Operation on Embedded Convective Clouds in Hunan Province

Based on NCEP 1°×1° reanalysis data, ground encryption houdy precipitation, FY-2E stationary satellite and Doppler radar data, the structural characteristics of precipitation clouds in Hunan Province and the effects of airplane precipitation operation were analyzed. The results show that under the effects of low-pressure system and southwest monsoon, Hunan was rich in water vapor, which was beneficial to the maintaining of precipitation clouds. During the process of the artificial precipitation operation over Hunan Province, convection developed vigorously, and precipita- tion was strong in the south of the province; embedded convective clouds were dominant and precipitation was weak in the east of the province. Cloud optical thickness correlated with ground precipitation positively. After catalyzing, echo at high altitudes responded firstly, and the echo intensi- ty increased gradually; the response of low-altitude echo lagged behind that of high-altitude echo. It shows that catalysis could lead to increase of upper precipitation particles in size and quantity. As time goes on, upper precipitation particles descended to low altitudes, so that echo intensity in- creased at low altitudes. It is clearly seen that catalysis could lead to increase of echo intensity and prolong the lifetime of target clouds to improve the area of strong echo zone, showing obvious positive catalytic effect. At the same time, houdy average precipitation in the affected region tended to increase stably and was obviously more than that of the contrast region where hourly average precipitation reduced gradually with time. The changing trend of hourly average precipitation in the affected region correlated positively with the response of radar echo.