内压缩流程高压液氧泵运行异常的影响分析及应急处理

因为电源故障,35000 m3/h内压缩流程空分设备的一台高压液氧泵突然停运,但另一台启动后工作不正常,此时只能采取紧急处理措施:边调整空分设备的运行工况,使其保持稳定,边处理高压液氧泵故障。待高压液氧泵运行正常后空分设备投入了稳定运行。简介空分设备工艺流程和两台高压液氧泵的控制要求,重点分析高压液氧泵停运对相关设备及精馏工况的影响,阐述高压液氧泵工作不正常时的应急操作方案。     

大型空分设备多级液氧泵轴封的拆卸与回装

内压缩流程空分设备配套液氧泵运行过程中,其轴封会因磨损而泄漏,需要经常检查或更换。简介液氧泵轴封的结构与工作原理,结合18000 m3/h空分设备配套液氧泵的运行经验,详细介绍液氧泵轴封的拆卸、回装及其注意事项。     

内压缩流程空分设备产品液氧泵的操作与维护

以太钢集团比欧西气体公司730t/d空分设备为例,分析了内压缩流程空分设备中产品液氧泵在试车和运行当中所遇到的问题;提出解决方案,使液氧泵长期稳定运行,保证了空分设备的正常生产。     

延长高压液氧泵运行周期的探讨和实践

28000 m3/h内压缩流程空分设备配套的高压液氧泵,在开车初期和运行过程中出现了轴承和密封损坏等异常情况,影响了空分设备的正常运行。通过实施技术改造和操作优化,延长了高压液氧泵的运行周期。简介高压液氧泵的技术参数,阐述技术改造和工艺操作优化措施,总结高压液氧泵的操作和维护经验。     

采用返流气膨胀循环的小型空分设备的研制

本文介绍了哈尔滨制氧机厂近年来研制成功的返流气膨胀循环,单级精馏,带高压液氧泵的单高氧空分设备——KZO-50型空分设备和返流气膨胀循环,双级精馏,带高压液氧泵及高纯压力氮的双高空分设备——KZON-50/120型空分设备的流程,主要技术经济指标,特点等,分析探讨了返流气膨胀循环的流程型式应用于小型空分设备节能的机理,提出了合理的选择上塔操作压力,减少液氧泵冷损失等对改善小型空分设备技术经济指标的重要性。     

分体式空分设备冷却积液阶段及冷启动时的特殊冷却方法

分体式空分设备特殊的结构布置及冷箱内工艺管线设置,使开车过程中的冷却较困难。结合多伦煤化工58000 m3/h空分设备的开车过程和临时停车后冷启动过程,介绍分体式空分设备冷却、积液阶段工艺液氧泵的异常运行状况,阐述在这两个阶段采取的工艺调整措施,使空分设备的各个部位得到彻底冷却,从而保证工艺液氧泵安全运行。     

与德士古渣油/沥青汽化制氨配套的新型空分设备

介绍南化公司从美国APCI公司引进的 4 0 0 0 0m3/h分子筛净化、空气增压膨胀、液氧泵、液氮泵流程的空分设备的生产能力与工艺流程及主要设备 ,并和传统的分子筛净化、氮增压膨胀、液氧泵空分流程进行了比较 ,提出了其优缺点。图 3表 1。     

白银有色20000m~3/h空分设备配置特点及调试总结

介绍白银有色KDONAr-20000/3200/650型空分设备的主要设备配置特点,叙述调试过程中实施的管线改造、空气进下塔控制阀改造和加装应急液氧泵变频器等改进措施,以及活塞式液氧泵启动时的优化操作。     

KDON-33600/27500型空分设备的设计缺陷及整改措施

介绍KDON-33600/27500型双泵内压缩流程空分设备在高压液空节流阀、液氧泵密封气和加温气流程以及膨胀机喷嘴加热器控制程序方面存在的设计缺陷,分析了这些缺陷对空分设备安全、稳定运行的影响以及采取的整改措施。     

杭氧高压液氧泵通过72小时连续低温运转试验

2014年12月29日,从南京杭氧气体有限公司试验现场传来好消息,由杭氧工装泵阀有限公司自主研发的高压液氧泵顺利通过了72小时连续低温运转试验。该液氧泵是为大型内压缩流程空分设备配套的关键部机,设计流量为75 m3/h,扬程为780 m(液氧出口压力可达8.8 MPa)。长期以来,大型煤化工配套内压缩流程空分设备高压液氧泵一直被国外公司垄断,导致了产品成本高、维修难、备件周期长等一系列问题。行业内呼吁国产化的需求日渐     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

可燃气体检测报警器测量结果的不确定度评定

本文详细介绍了可燃气体检测报警器示值误差测量结果的不确定度评定方法。     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。     

心电图机电压测量示值误差测量值的不确定度评定

本文介绍了心电图机电压测量示值误差测量值的不确定度评定与表示方法。     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.