汽轮机叶片的带负荷冲洗

云南富瑞化工有限公司800kt／a硫磺制酸装置汽轮机叶片存在积垢，为保证系统工艺稳定及设备安全运行，对叶片进行了一次不停车带负荷冲洗。冲洗时，汽轮机调速汽门全开，汽轮机进口蒸汽压力为3．4MPa、温度从430℃逐渐降到280℃，运行1～2min后，因汽轮机进汽量大，造成汽轮机前轴振动升高70mm、后轴振动升高48mm，推力轴瓦温度升高7℃，轴向位移增加0．1mm。在冲洗中，     

卧式辊磨常见故障分析

我公司从法国FCB公司引进的φ3800Horomill(生产能力120t/h)至今累计运转近1年,其水平振动要求在1.5mm/s以下,垂直振动要求在3.0mm/s以下;支承磨体出、人口的大小4块滑履瓦温度要求<90℃,但在生产运行中有时会出现磨体振动偏大和滑履瓦温度过高等异常状况.     

YL24000A烟气轮机振动原因分析及探讨

能量回收烟气轮机工质中含固体颗粒,且运行温度较高650~700℃,不稳定状况易发生,根据实际运行经验并结合机组的特点,对烟气轮机运行特点进行分析,找出引起烟气轮机频繁振动超标的问题所在,以进行解决,保证装置的长周期平稳运行,进一步提高机组节能效果。     

连续重整再生风机异常振动的消除

某石化公司连续重整再生风机大修后振动增大,并在介质温度下降和风雨天气时振动上升明显,威胁机组平稳运行。通过分析DCS记录和振动数据,认为存在以下问题:机组存在应力变化和膨胀变形;转子存在一定的不平衡和弯曲。通过采取保温修复措施,消除了风机轴承振动受介质温度和天气变化的影响,保证了机组的长周期运行,转子的不平衡和弯曲择机处理。     

巧用测温枪发现万向联轴器振动经验

笔者到现场有随身携带测温枪的习惯。2011年6月,我公司一台CLF140-65辊压机动辊传动系统发现振动。反复检查,起先以为是减速器振动,听诊声音无异常;又怀疑是对中问题,就将电动机位置进行了调整,振动依旧。在空负荷试机20多分钟后,偶然用AR802B型测温枪扫描后比较动辊和定辊万向联轴器温度,发现动辊万向联轴器出端比定辊的温度高出12℃左右。当时环境温度是30℃左右,正常万向联轴器温度是32℃,异常万向联轴器温度是44℃。     

催化烟机振动大原因分析及应对措施

催化裂化装置烟气轮机回收烟气中能量,烟气中含有催化剂等固体颗粒,且运行温度较高660-690℃,不稳定状况易发生。根据实际运行经验及机组的特点,结合2012年烟机两次切除缺以及装置停工抢修情况,对烟气轮机运行特点进行分析,找出引起烟气轮机振动频繁超标的原因,制定合理的故障处理措施进行解决,保证袈置长周期平稳运行。     

全同立构聚丙烯振动注射试样晶体结构的变化

采用自行研制的压力振动注射装置，在不同熔体温度、振动频率、振动压力下成型了全同立构聚丙烯振动注射试样，并进行了WAXD、DSC和SEM测试。结果表明，当成型温度为190℃时，在高的振动频率下，有γ晶生成；在高振动压力条件下，有β晶生成。当成型温度为230℃，无论是在高频率，还是高压力振动，都有β晶生成。同时，振动还将改变试样的熔点，提高试样结晶度，细化晶粒。     

三轴式离心式空压机故障原因分析及对策措施

对三轴式离心式型空气压缩机出现的各级温度高、振动高和排气量降低等故障的原因进行分析 ,对其冷却水和入口空气过滤器的改造实施后 ,使各级温度、振动都明显降低 ,排气量也十分稳定 ,运行周期大大地延长 ,从而保证整个空分装置的安、稳、长、满、优运行。     

振动流化床出口物料温度偏高的原因及整改措施

由于复合肥生产装置中的振动流化床存在设计缺陷,导致其出口物料温度偏高,增大了复合肥产品结块的可能性。从设计、安装、操作等方面分析造成振动流化床出口物料温度偏高的原因,并采取相应的改造措施。改造后,振动流化床出口物料温度下降约9℃,效果明显。     

热声发动机在低温余热利用方面的研究

以低温排热的有效利用为目的,设计制作了一台热声发动机的实验样机。通过实验,揭示了热声自激振动与热声强制振动现象发生的条件与机理,研究了热声发动机的关键部件——板叠的形状与材质对系统的起振温度的影响。结果表明,合理设计板叠的结构和合理选择板叠的材料,可以使得系统在较低的温度下起振。系统的最低起振动温度约为60℃。而从热声振动的方式来看,强制振动比自激振动具有更低的起振温度。     

Detonation of a Column of a Chemically Active Bubbly Medium in a Liquid

The problem of a detonation wave propagating in a cylindrical column of a chemically active bubbly medium screened by a liquid from the tube walls is formulated and numerically solved within the framework of the Iordanskii–Kogarko two-phase model with allowance for energy dissipation due to acoustic radiation of bubbles. The wave structure of the reaction zone and the detonation velocity of the bubbly medium column are calculated. It is found that the self-sustaining wave can propagate with a velocity greater than the velocity of one-dimensional bubble detonation by a factor of 1.5–2.5.     

Extraction into a flow of a fluid with a velocity gradient

Unsteady extraction from a system of semi-infinite capillaries to the flow of a fluid with a linear velocity gradient is studied. An assumption that the diffusion in the flow is a quasi-steady-state process is taken to obtain a linear equation for the local mass flux from the pore space, which involves fractional derivatives with respect to time and flow coordinate. Limiting solutions for the total diffusion flux at small and large times that cover the entire time interval are found.     

Separation of mixtures and distribution of a liquid on a structured packing in a large-scale model of a distillation column

A large-scale experimental setup is designed to study the hydrodynamic parameters and the mass-transfer efficiency in a countercurrent flow of mixtures of Freon R21 and Freon R114 on structured packings in a column 0.9 m in diameter. The study deals with the local and integral parameters of separation of the mixture, the degrees of nonuniformity of the flow rates and concentration distributions of the liquid and vapor phases over a cross section and on the column wall, and the pressure difference while varying the number of packing layers and their rotation angle. The mass-transfer processes while independently varying the liquid and vapor flow rates over wide ranges are also investigated. Experimental data are presented to illustrate the effect of the operating parameters on the height of an equivalent theoretical plate, the relative pressure difference, and the distributions of the local parameters of the flows.     

Interaction of a Shock Wave with a Cloud of Aluminum Particles in a Channel

Interaction of an incident shock wave (with a rectangular or triangular profile behind its front) with a finite-width semi-infinite cloud of aluminum particles located in a channel along the plane of symmetry is numerically simulated. Shock-wave interaction with the leading edge of the cloud results in the formation of a vortex that leads to cloud dispersion. Reflection of the curved shock wave from the plane of symmetry may be regular or may include the formation of the Mach stem. If the cloud is loaded by a rather strong shock wave, a detonation wave is formed in the cloud. In this case, the flow is periodic, which is caused by passing of transverse waves and their reflection from the walls.     

Reflection of a shock wave from a rigid wall in a mixture of a liquid metal and solid particles

The problem of reflection of shock waves and expansion waves from a rigid wall in a mixture of liquid iron and small molybdenum crystals is considered. The study is performed within the framework of equilibrium and nonequilibrium approximations of mechanics of heterogeneous media with different pressures of the components. The mathematical model is verified by fitting the dependence of the equilibrium-frozen velocity of sound on the initial pressure in the mixture with available experimental data. In the equilibrium approach, the dependence of the type of the reflected wave on the type of the incident wave is determined. Direct numerical calculations within the framework of the nonequilibrium model of mechanics of heterogeneous media confirmed the validity of the reflection chart obtained. The possibility of significant compacting of molybdenum particles in reflected waves is revealed. Translated fromFizika Goreniya i Vzryva, Vol. 36, No. 4, pp. 97–107, July–August, 2000. This work was performed within the framework of the Integration Project No. 97-24 of the Siberian Division of the Russian Academy of Sciences.     

Transient Outflow of a Liquid from a System of Holes in a Horizontal Tube

The transient outflow of a liquid from a perforated horizontal tube as a result of abruptly applied constant pressure is studied theoretically and experimentally. Equations and a computer program are developed for estimating the parameters of such transient processes. Retardation of the liquid outflow is observed, and its mechanism is discussed.