浅谈20万吨甲醇项目变频器控制方案探讨

随着高低压变频技术的发展和成熟,变频器在化工、冶金、石油、制药等行业得到广泛应用。变频器控制方案也从传统方式向智能化、数字化、网络化发展。笔者就产20万吨甲醇项目变频器控制方案与冶金行业高压水除磷系统变频器控制方案进行研究分析。     

ACS800变频器在海南东方甲醇装置中的应用

主要阐述了ABB的ACS800变频器在海南东方甲醇装置回收塔回流泵电动机上的应用,详细介绍了该电动机使用变频器的控制原理及针对由于变频器易受晃电的影响而进行的抗晃电改造措施。结合实际使用情况介绍了变频器转矩控制的优点和建立方法及变频器低负荷功能的作用和设置方法,并分析了使用电抗器的必要性及安装注意事项。最后总结变频器使用的几点注意事项,以期达到跟同行交流学习的目的。     

甲醇制烯烃装置水洗塔堵塞原因分析及处理

甲醇制烯烃装置中,水系统堵塞问题目前已成为制约其正常生产的一大因素。本文主要从水洗塔二甲苯注入量、注入点、注入时间的选择以及注入后的萃取效果等几个方面对水洗塔结蜡原因和处理措施进行论述。     

基于PLC控制的甲醇塔压力参数的控制系统设计

针对甲醇合成塔在实际生产中对压力参数的要求,设计了一套由PLC、变频器、压力传感器、气体压缩机等主要设备构成的变频压力控制系统,具有自动变频运行功能。提出基于PID的压力参数控制方案,解决了传统压力控制方式中存在的问题,增强了系统的可靠性,提升了系统的总体性能。     

无功补偿及无源滤波研究

正0引言在工业生产中,由于变频器设备大量使用,变频器产生了大量谐波电流注入电网,对电网造成污染,对供电设备的性能产生影响甚至使设备受损。因此在供配电系统设计时,需要对谐波电流进行治理,使注入电网的谐波电流满足国家标准。目前谐波电流治理技术主要有无源滤波技术和有源滤波     

焦炉煤气、甲醇弛放气制合成氨装置的节能降耗改造总结

简述了焦炉煤气、甲醇弛放气制合成氨的工艺流程和技术特点,介绍了完善其生产装置的主要节能改造措施:在化学水工段,将原水管线直接接入多介质过滤器;在提氢工段,不使用蒸汽加热器和冷却器;在合成工段,废热锅炉给水泵中加装变频器。改造结果表明:焦炉煤气、甲醇弛放气制合成氨系统的化学水工段、提氢工段、合成工段运行更加平稳,可降低能耗,并具有较好的经济效益。     

600kt/a甲醇制烯烃工业装置水洗塔压差高的原因分析及处理措施

神华榆林能源化工有限公司600 kt/a甲醇制烯烃工业装置(配套甲醇装置产能为1.8 Mt/a)催化剂由SMC-001更换为UOP-280后,装置运行3个月后即由于蜡状物附着在塔盘上造成水洗塔压差较高,严重影响甲醇进料负荷的提升。对水洗塔蜡状物进行红外光谱分析,确认蜡状物主要成分为六甲基苯。通过在水洗塔注入点2注入阻垢分散剂后,换热器的换热效果明显增强,进而通过注入柴油、二甲苯并采用高压水机械清洗后,最终解决了水洗塔压差高的问题,使甲醇进料负荷得以提升;但这些措施会在一定程度上使水洗水的COD升高,增加污水汽提塔及污水处理系统的负荷。     

联醇装置存在问题对铜洗工段的影响及解决办法

我公司8．13合成新系统联醇装置设计年产粗甲醇25kt,于2004年4月投入生产，而且一次开车成功，为公司注入了新的经济增长点。     

注醇工艺在气田应用的可行性分析

电伴热工艺在低温时达不到防止水合物形成的作用,需要由注醇工艺保证正常生产,通过对电伴热+注醇工艺与完全注醇工艺进行对比,认为目前A气田更适合于电伴热+注醇工艺。但随着生产井的增多,甲醇消耗量增大,成本费用较高,若建立甲醇回收系统,对注入的甲醇回收循环利用,可以适应A气田快发展形势下高甲醇需求量,降低了生产成本,可以进行推广应用。     

天然气集输系统水合物抑制剂用量优化

天然气生产和运输系统容易在冬季低温时形成水合物堵塞管道,水合物抑制剂注入法在实际中是比较常用的方法,针对P气田A气井冬季的实际情况,通过运用PIPESIM软件分别对三种水合物抑制剂用量进行优化,并对其效果进行比较。结果表明,甲醇、乙醇的最优注入量分别为65、200 L/d,甲醇和乙二醇配比为3:2时,水合物抑制效果最好。该研究为气田集输系统提供了可靠的醇类抑制剂用量优化方法,降低了生产成本。     

单缸补气转子式压缩机在热泵系统中制热性能

利用中间补气技术将单缸滚动转子式压缩机应用于空气源热泵系统中,系统地研究以R410A为冷媒的热泵系统在变频、变补气压力工况下制热性能的变化规律。实验结果表明：中间补气系统的制热量及系统功率均随着压缩机频率f、中间补气压力p_inj的增加呈上升趋势,同频率下系统功率则以线性方式增长,而系统制热量随着补气压力及频率的增大,其相对增长率逐渐减小。因此COP_h在低频时存在最佳补气压力,而在高频时无极值点;与单级压缩系统相比,在800~1200 kPa、50~80 Hz范围内,中间补气系统的制热量、功率、COP_h最大提升分别为27.55%、30.75%、7.1%。随着频率及补气压力的增加,系统COP_h下降,因此中间补气技术应与合理的控制策略相结合,可使中间补气系统达到节能高效的目的。     

Operation Characteristic Analysis of a Direct Methanol Fuel Cell System Using the Methanol Sensor‐less Control Method

The application of methanol sensor‐less control in a direct methanol fuel cell (DMFC) system eliminates most of the problems encountered when using a methanol sensor and is one of the major solutions currently used in commercial DMFCs. This study focuses on analyzing the effect of the operating characteristics of a DMFC system on its performance under the methanol sensor‐less control as developed by Institute of Nuclear Energy Research (INER). Notably, the influence of the dispersion of the methanol injected on the behavior of the system is investigated systematically. In addition, the mechanism of the methanol sensor‐less control is investigated by varying factors such as the timing of the injection of methanol, the cathode flow rate, and the anode inlet temperature. These results not only provide insight into the mechanism of methanol sensor‐less control but can also aid in the improvement and application of DMFC systems in portable and low‐power transportation.     

Effect of injection and ignition timings on performance and emissions from a spark-ignition engine fueled with methanol

Optimal injection and ignition timings and the effects of injection and ignition timings on performance and emissions from a high-compression direct-injection stratified charge spark-ignition methanol engine have been investigated experimentally. The results have shown that direct-injection spark-ignition methanol engine, in which a non-uniform mixture with a stratified distribution can be formed, has optimal injection and ignition timings to obtain a good combustion and low exhaust emissions in the overall mode range. Both methanol injection timing and ignition timing have a significant effect on methanol engine performance, combustion, and exhaust emissions. At an engine speed of 1600 rpm, full load, and optimal injection and ignition timings, methanol engine can obtain shorter ignition delay, lesser cycle-by-cycle variation, the maximum in-cylinder pressure, the maximum heat release rate, and higher thermal efficiency compared to the case of non-optimized injection and ignition timings. For methanol engine, the optimization of injection timing and ignition timing can lead to an improvement of brake-specific fuel consumption of more than 10% compared to non-optimized case in the overall load range and engine speed of 1600 rpm. The best compromise between thermal efficiency and exhaust emissions is reached at optimal injection and ignition timings.     

变频器在注塑机调速系统中的节能分析及应用

运用变频器对注塑机进行节能改造设计,采用比例流量、比例压力信号动态控制变频器的输出频率,从而控制油泵电机的转速,实现变压节能。设计了变频器外部接口电路,进行了变频器参数设定和机电联调。经改造的注塑机系统的精度和稳定性极大提高,操作方便,节能效果明显,产生了显著的经济效益和社会效益。     

Effects of ambient temperature on firing behavior and unregulated emissions of spark-ignition methanol and liquefied petroleum gas/methanol engines during cold start

The effects of the ambient temperature on the firing behavior and the unregulated emissions (formaldehyde and unburned methanol emissions) of electronically controlled inlet port injection spark-ignition methanol and liquefied petroleum gas (LPG)/methanol engines during the cold start were investigated experimentally by means of a single-cycle fuel injection strategy. The test results indicated that the minimum amount of methanol injected per cycle to ensure the methanol engine reliable firing increases 86% with the reduction of the ambient temperature from 301 to 289 K. With the ambient temperature below 289 K, the methanol engine cannot be started reliably without the other assistant measures even with a large methanol injection. The LPG only played a part of start-aids in the LPG/methanol engine. Using additional LPG injected into the inlet port results in a reliable firing of the LPG/methanol engine at low ambient temperature during cold start. When the ambient temperature drops, the mass ratio of injected LPG/methanol for the reliable firing of the LPG/methanol engine during cold start increases rapidly. The maximum combustion pressure in the cylinder, the maximum instantaneous engine speed, and the formaldehyde emissions increase significantly and the unburned methanol decreases obviously with the rise of the ambient temperature.     

甲醇合成催化剂失活问题分析与处理

介绍了Shell粉煤气化制甲醇工艺中甲醇合成系统流程及生产运行情况。对合成塔催化剂运行情况进行了总结;就催化剂失活、更换频率过快问题进行了分析;并对合成回路系统进行了一系列改造:在现有合成塔上并联1台新的合成塔,分担现有合成塔一部分负荷,以降低现有合成塔催化剂生产强度,降低床层热负荷,增强催化剂抗中毒能力,延长催化剂寿命。结果表明:改造后,降低了经济运行成本,每年直接节省334万元,且确保了装置的长周期、高负荷稳定运行。     

超声作用下碱催化大豆油酯交换反应制备生物柴油

采用低频率超声（40kHz）强化KOH催化大豆油和甲醇酯交换反应制备了生物柴油。结果表明,超声空化作用的传质和乳化效果较传统机械搅拌作用显著。不同超声功率对酯交换反应的强化作用不同,超声功率60-80W对生物柴油制备影响显著。此外,超声作用下酯交换反应时间大大缩短,催化剂和甲醇的用量也有所减少。在催化剂用量为1．0％、醇油摩尔比为6：1、45℃水浴条件下,超声作用10min,甲酯含量高达99％。     

1-丁烯中微量甲基叔丁基醚和甲醇含量的测定方法改进

根据测定1-丁烯中微量甲基叔丁基醚和甲醇的分析方法中存在的问题,分别对进样方式、毛细管色谱柱和仪器操作条件作了改进,建立了一次进样便可同时检测甲基叔丁基醚和甲醇的气相色谱法。改进后的方法操作简便,分离效果及重复性良好。     

网络化高压变频器在油田注水中的应用

通过对中原油田注水站应用高压大功率变频调速节能技术的原理及效果分析,揭示了油田注水系统应用变频实施节能改造的巨大潜力。     

Partial oxidation of methane with air for methanol production in a post-plasma catalytic system

Partial oxidation of methane to methanol via post-plasma catalysis using a dielectric-barrier discharge was performed under mild reaction conditions. Air was used as the oxidizing co-reactant because of its economical practicality. Three catalysts impregnated with Pt, Fe₂O₃, CeO₂ on ceramic supports located downstream of the discharge zone were examined for increased selectivity towards methanol. It was found that all three catalysts had no significant effect on the conversion of methane, but enhanced methanol selectivity, which could be explained by a two-stage reaction mechanism. The Fe₂O₃-based catalyst showed the best catalytic activity, and high stability in the reaction. The methanol selectivity of the Fe₂O₃-assisted plasma process was 36% higher than that of the non-catalytic system at a rather low catalyst temperature (150 °C). In addition, the effects of input power, discharge frequency, discharge gap distance, total flow rate, and methane/air ratio on methane conversion and methanol yield were also studied.