空压机二级振动异常的原因分析与处理

介绍一起空压机二级振动异常的故障,分析了故障原因,通过安装空压机叶轮在线清洗系统解决了叶轮结垢问题,保证空压机安全运行。     

空压机同步电机失磁的分析和处理

由于离心空压机驱动同步电机发生失磁故障,导致空压机的联轴器断裂。简介空压机和驱动同步电机的性能和参数,详细介绍故障经过、原因分析过程和处理措施及效果。     

空压机叶轮结垢原因及处理措施

通过对新空分装置空压机近年来运行和故障的分析,得出造成空压机叶轮结垢的主要原因是机组进口过滤器的过滤效果差、空压机级间管道和冷却器内壁锈蚀。分析引起故障的原因,并采取相应的措施,实现空压机长周期稳定运行。     

DH-90型空压机油泵互投逻辑控制的完善

2#14000m3/h空分设备DH-90型空压机在切换油泵操作中,因互投逻辑问题出现多次故障,致使空压机联锁停车,分析故障原因,逐步修改并完善油泵互投逻辑控制,实现空压机稳定运行。     

一起5TYD/160型空压机进水故障分析

在6500m3/h空分设备正常运行过程中,DCS系统服务器失电使电脑黑屏后程序出错,空压机放空卸压时空压机出口至空冷塔排气阀没有联锁关闭止逆阀,使空压机卸压放空时产生虹吸现象,造成空压机进水。简介故障发生过程,阐述故障原因的分析和采取的处理措施。     

60000m~3/h空分设备空压机停车故障分析与处理

由于60000 m3/h空分设备配套的VK200-3型空压机导叶开度偏差控制故障和一级导叶无规律窜动,导致空压机因一级轴振动超标而停车。通过改造空压机导叶控制和将二、三级导叶开度固定在100%而彻底排除了故障,确保了空分设备安全、稳定运行。简介VK200-3型空压机结构,详细介绍停车故障的分析和处理过程。     

空压机的不稳定工况及对空分设备的影响

详细介绍了齐鲁石化公司第二化肥厂空压机组C/T-151发生的三次故障、处理措施及从中获得的经验和教训,分析了空压机不稳定故障的原因,最后分析了空压机不稳定运行对空分设备的不良影响。表3。     

制约空压机长周期运行的因素及处理措施

通过对引进C150MX3型空压机近几年来的运行和故障情况的分析,得出制约空压机长周期运行的3个因素:冷却器结垢、扩压器腐蚀和二级振动值高。分析了引起故障的原因,并采取了相应措施,实现空压机长周期稳定运行。     

螺杆式空压机运行中发生故障原因分析及消除措施

螺杆式空压机具有独特的优点受到电厂的欢迎,不过在运行中或多或少会出现一些故障,特别是用在电厂气力输灰系统的螺杆式空压机出现故障后会直接影响系统的安全稳定运行。针对L160-7.5W型螺杆式空压机在运行中出现的故障进行原因分析,从中找出规律,并提出消除措施,以供同类型设备参考。     

浅析螺杆式空压机的维护保养和故障维修

螺杆式空压机因具有安全、节能、环保等优势,现已广泛应用于各煤矿、油田的日常生产当中,并发挥着不可替代的重要作用。螺杆式空压机的使用直接关系着煤矿、油田的日常产量,因此对于其维护保养及故障维修倍加重要。文章简单阐述了螺杆式空压机的维护保养知识,接着分析了螺杆式空压机可能会出现的故障,并给出了相应的维修方法。     

PSA制氧用空压机的选型与设计

列述了变压吸附 (PSA)制氧机之空压机设计中要重视的八个环节 :要无油润滑、空气量要恰当、要能适应电压波动、噪声要低、水分要吹除、要注意环境条件、可靠性要高、选型要好。     

Atomic Fe–Nx Coupled Open‐Mesoporous Carbon Nanofibers for Efficient and Bioadaptable Oxygen Electrode in Mg–Air Batteries

The recently emerging metal–air batteries equipped with advanced oxygen electrodes have provided enormous opportunities to develop the next generation of wearable and bio‐adaptable power sources. Theoretically, neutral electrolyte‐based Mg–air batteries possess potential advantages in electronics and biomedical applications over the other metal–air counterparts, especially the alkaline‐based Zn–air batteries. However, the rational design of advanced oxygen electrode for Mg–air batteries with high discharge voltage and capacity under neutral conditions still remains a major challenge. Inspired by fibrous string structures of bufo‐spawn, it is reported here that the scalable synthesis of atomic Fe–N_x coupled open‐mesoporous N‐doped‐carbon nanofibers (OM‐NCNF‐FeN_x) as advanced oxygen electrode for Mg–air batteries. The fabricated OM‐NCNF‐FeN_x electrodes present manifold advantages, including open‐mesoporous and interconnected structures, 3D hierarchically porous networks, good bio‐adaptability, homogeneously coupled atomic Fe–N_x sites, and high oxygen electrocatalytic performances. Most importantly, the assembled Mg–air batteries with neutral electrolytes reveal high open‐circuit voltage, stable discharge voltage plateaus, high capacity, long operating life, and good flexibility. Overall, the discovery on fabricating atomic OM‐NCNF‐FeN_x electrode will not only create new pathways for achieving flexible, wearable, and bio‐adaptable power sources, but also take a step towards the scale‐up production of advanced nanofibrous carbon electrodes for a broad range of applications.     

Using a new strategy to optimize the bump design parameters in flip chip packages

Flip chip technology has rapidly progressed in concert with the high speed and small dimension trends in electronic devices. The bump interconnects design dominates the performance of a flip chip package. This study produced a new strategy to optimize the geometric design parameters of the bump from the electrical standpoint. The first incident voltage was employed as the optimization objective function in order to reduce the response time delay in the binary command as well as maintain the chip level efficiency. Genetic algorithms were used for the search routines to evaluate the best bump geometric solutions. Two cases, 1.5 v V and 3.3 v V power supply voltage, were adopted to conduct this research in both air and underfill environments. The results show that the standoff height and the bump pitch determined in the underfill environment are greater than in the air environment. As the power supply voltage increases, the standoff height and bump pitch become more significant. A powerful optimal window for bump design parameters is thus established.     

Design criteria for high voltage leads for superconducting power systems

Future applications of superconductivity within power systems require reliable high voltage leads from ambient air into the LHe-region. The main electrical, thermal, and thermo-mechanical design criteria are discussed, and guiding rules are given for the construction of such leads. Practically feasible designs are described which are based on the experience with various tested prototype leads.     

The effect of adsorbates on the space-charge-limited current in single ZnO nanowires

We studied the influence of adsorbates on the space-charge-limited current (SCLC) in individual ZnO nanowires through varying the bias voltage, laser illumination, and ambient pressure. In dark and air conditions, the free carriers were depleted by the surface adsorbates, and electrons injected from the electrode to the nanowire dominated the electron transport properties. Under laser illumination, the current-voltage characteristic was linear at low voltage and superlinear at high voltage, and the SCLC regime occurred at high voltages due to the surface desorption. The time response of photoconductivity further revealed the dynamic process of elimination of SCLC by desorption of oxygen molecules at the ZnO nanowire surface.     

Defect Engineering toward Atomic Co–Nx–C in Hierarchical Graphene for Rechargeable Flexible Solid Zn‐Air Batteries

Rechargeable flexible solid Zn‐air battery, with a high theoretical energy density of 1086 Wh kg^?1, is among the most attractive energy technologies for future flexible and wearable electronics; nevertheless, the practical application is greatly hindered by the sluggish oxygen reduction reaction/oxygen evolution reaction (ORR/OER) kinetics on the air electrode. Precious metal‐free functionalized carbon materials are widely demonstrated as the most promising candidates, while it still lacks effective synthetic methodology to controllably synthesize carbocatalysts with targeted active sites. This work demonstrates the direct utilization of the intrinsic structural defects in nanocarbon to generate atomically dispersed Co–N_x–C active sites via defect engineering. As‐fabricated Co/N/O tri‐doped graphene catalysts with highly active sites and hierarchical porous scaffolds exhibit superior ORR/OER bifunctional activities and impressive applications in rechargeable Zn‐air batteries. Specifically, when integrated into a rechargeable and flexible solid Zn‐air battery, a high open‐circuit voltage of 1.44 V, a stable discharge voltage of 1.19 V, and a high energy efficiency of 63% at 1.0 mA cm^?2 are achieved even under bending. The defect engineering strategy provides a new concept and effective methodology for the full utilization of nanocarbon materials with various structural features and further development of advanced energy materials.     

Excellent ferroelectricity of thin poly(vinylidene fluoride-trifluoroethylene) copolymer films and low voltage operation of capacitors and diodes

Characteristics of metal-ferroelectrics-metal (MFM) capacitors and meta -ferroelectrics-insulator-semiconductor (MFIS) diodes with poly(vinylidene fluoridetrifluoroethylene) [P(VDF-TrFE)] copolymer films thinner than 100 nm were investigated. The films were prepared by spin cast process and were annealed at 140 degrees C in air for crystallization. The ferroelectric properties are equivalent to those of oxide ferroelectrics, even under low voltage or high frequency operation.     

Actuation of electrochemical, electro-magnetic, and electro-active actuators for carbon nanofiber and Ni nanowire reinforced polymer composites

Actuation of electrochemical, electro-magnetic, and electro-active actuators composed of CNF and/or Ni nanowire/polymer nanocomposites was evaluated with different materials and preparation processes. The actuated strain was compared with frequency, applied voltage, and wave type. The hysteresis of the actuated strain was continuously delayed in electrochemical actuators, whereas the strain was uniformly actuated in the electro-magnetic actuators. The actuated strain decreased with increasing frequency in both electrochemical and electro-magnetic actuators. In magnetic fields the actuated strain increased with increasing Ni nanowire content whereas the current increased with applied voltage. Ni nanowire/cellulose actuators in a magnetic field responded better at high frequencies, compared to the other actuators studied. Actuated strain of cellulose or Ni nanowire/cellulose nanocomposite in air was larger than either PVDF or PVDF/cellulose nanocomposite. In Ni nanowire/cellulose nanocomposite, actuated strain also decreased with increasing frequency and increased with increasing voltage. Electro-active actuators responded well in air when low voltages and high frequencies were applied compared to the other two actuators. Electro-active actuators in this paper have unique advantages for many practical applications, including easy fabrication, lightweight and low application voltages.     

Positive corona progression over profiled insulator surfaces near the breakdown condition

Experimental observations are presented of the development and propagation of positive impulse corona near the breakdown condition in a point plane gap in air at atmospheric pressure in the presence or absence of insulators having simple cylindrical and profiled surfaces. Optical techniques have been used and the effects of the insulator materials have been demonstrated. All the results with corona were obtained using an applied peak impulse voltage of 0.9U₅₀ in each case, where U₅₀ is the 50% breakdown voltage of the gap. Comparisons were made between air, polytetrafluoroethylene (PTFE) and porcelain surfaces. It has been demonstrated that corona development in the gap is dependent on the relative permittivity of the insulator material, the profiles and the proximity of the insulator to the high voltage point electrode. Simultaneous photomultiplier records and photographs taken on fast film with Quartz optics show details of corona development using the UV region of the spectrum.     

碱性锌/空气电池阳极(锌电极)材料研究进展

碱性锌/空气电池具有比能量高、输出电压稳定、无污染、原材料便宜、易得等优点而受到广泛的重视.锌电极作为锌/空气电池的阳极,其性能的好坏将直接影响电池的放电性能(输出功率、循环寿命、放电深度等)和贮藏性能.锌电极存在的主要问题有:枝晶、形变、自腐蚀、钝化等.针对上述问题,从锌电极材料的物理性能,以及电极和电解质的添加剂入手,综述了国内外最新的研究进展.