往复式压缩机工艺管线振动超标与治理

针对天然气长输管线常用的往复式压缩机工艺管线振动严重超标的问题,通过对不同工况下关键测点的振动测试和压力脉动分析,结合测点的测试数据和频谱特性,得出了压力脉动是导致管线振动主要原因的认识。为了控制压力脉动以消减激振力,根据现场的工艺要求,提出了增加汇气管的缓冲容积和改善管道配置的治理措施。完成整改后,再次进行了关键测点的振动测试和压力脉动分析,数据表明:整改前后压缩机在相同工况参数下运行时,测点最大振动位移由289.76μm降低到47.2μm;最大振动速度由34.26 mm/s降低到5.18 mm/s;压力脉动也符合API 618标准的要求。同时,管线的振动烈度满足多台压缩机同时运行的要求,使得增压站的天然气处理量至少由67.41×10~4m~3/d提升到119.52×10~4m~3/d。该案例表明,对压缩机进行变工况振动测试和频谱特性分析,可方便地找出主要振动源,为管道的减振治理提供依据。     

Reconnaissance report on geotechnical damage caused by a localized torrential downpour with emergency warning level in Kyushu,Japan

Kumamoto and Kogoshima prefectures are located in the southern Kyushu district of western Japan. In July 2020, a warm, humid air front triggered the delayed rains of the rainy season, resulting in torrential rains in many parts of Japan, especially in Kyushu. In particular, heavy downpours occurred in the southern Kyushu district on July 4th, causing severe damage to much of the infrastructure. Details could not be analyzed as usual because some branch office of local government were also damaged by floods. The spatial distribution of precipitation in the Kuma River basin, in the southern part of Kumamoto, was characterized by the uniformity of 400–500 mm on July 3rd and 4th. Finally, emergency warnings of torrential rain were issued for the southern Kumamoto and the northern Kagoshima Prefectures by Japan Meteorological Agency (JMA) at 4:50 a.m., July 4th, 2020. Then, the active rain front gradually shifted towards northern Kyushu. Again, torrential rain fell on northern Kyushu in the afternoon due to a stagnant rainy season front, and the JMA issued an emergency warning for a localized torrential downpour for parts of Fukuoka, Saga and Nagasaki prefectures at 4:30 pm. Gradually, the damage status involving geodisasters such as several types of slope failures, road subsidence, damage of the river levee was reported by local governments in each area where there had been emergency warnings.Based on the brief report of the pre-investigation team from the Kyushu branch of the Japan Geotechnical Society (JGS) in the first week after the disaster on July 4th, the geo-research teams investigated the following: 1) landslides; 2) damaged roads; 3) damaged river levees, and 4) any geotechnical infrastructures which were partially damaged and may be even more severely damaged by the next torrential rain. This reconnaissance report introduces the geological features in Kyushu, the analysis of precipitation distribution and geotechnical damages on the slope failures, road failures and river embankments based on reports obtained from July 4th to August 31st, 2020.     

往复式压缩机配管设计

结合具体工程实例,从设备平面布置、主要工艺管线和辅助系统管线的设计及支架设置等方面,介绍了往复式压缩机的配管设计,并具体分析了几种防振支架。     

Improving piping resistance using randomly distributed fibers

Piping is a problem that commonly occurs downstream of hydraulic structures under the influence of upward seepage. Piping is considered as the main mechanism of hydraulic structures failures. In this work an experimental program was set for determining the seepage velocity and piping resistance for unreinforced and randomly reinforced silty sand samples. Two types of fiber were used for preparing the reinforced samples. The experimental tests were carried out for different fiber contents (0.5, 0.75, 1.0 and 1.25%) and fiber lengths (5, 25 and 35 mm) under different hydraulic heads. Discharge velocity and seepage velocity of water flow through unreinforced and reinforced samples were calculated and compared with unreinforced sample. The results show that the inclusion of fibers reduced the seepage velocity, increased the piping resistance and increased the critical hydraulic gradient hence, considerably delaying the occurrence of piping. Furthermore, the amounts of increase in the piping resistance and hydraulic gradient are functions of percent and length of fibers.     

常减压蒸馏装置转油线管道设计

列出了大型常压和减压蒸馏装置加热炉出口转油线管道设计的有关原则及常见的配管方式,适用于常压转油线和减压转油线的管道设计。     

应用CFD技术预测管道离心泵性能

采用多参考坐标系和标准k-ε湍流模型,应用流体动力学软件FLUENT对IS125型管道离心泵的内部流场进行模拟计算,得到内部的压力和流动速度分布,进而计算出泵的特性曲线,并与试验性能曲线进行了对比。对比结果表明,应用CFD技术预测管道离心泵性能具有较高的精度和工程应用价值。     

波导杆辅助声发射检测承压管道泄漏实验研究

在实验室将3根波导杆焊在实验用承压管道上,建立了声发射检测系统。通过对承压管道泄漏过程的声发射在线监测,分析了在不同压力、不同泄漏孔径情况下,波导杆上传感器所接收的信号幅度的规律,得出了波导杆可以应用于特殊工况下管道气体泄漏声发射检测的结论。     

铰链式膨胀节在工程中的应用

在利用膨胀节对高温管系进行热膨胀补偿的设计中,由于管系形式越来越复杂、管系上不同方向的热膨胀量也变得越来越大,单独使用轴向膨胀节、复式膨胀节或压力平衡式膨胀节已不能完全满足工程要求,且效果也不尽理想。而铰链式膨胀节的组合应用则使一些棘手问题迎刃而解,文章即利用工程实例来说明铰链式膨胀节在管系热膨胀补偿中的应用和计算方法。     

Determining the boundary conditions by estimating RDOFs CMS for piping system

It is difficult to obtain boundary conditioners for air conditioner piping system by FE model. An estimating rotational degree of freedoms (RDOFs) component mode synthesis (CMS) method is presented and used to determine the boundary conditions. This paper presents the method to determine the boundary conditions of the piping system from experimental data. A piping system of the air conditioner is carried out as an example using MSC. Nastran, and the comparisons between the results and the experimental ones show the achievements.     

浅谈氨制冷压力管道工艺要求及不停机检测技术

根据氨制冷管道特种设备最新的国家法规及标准,首先阐述氨制冷压力管道工艺、检验要求及质量控制问题,然后介绍氨制冷压力管道不停机检测技术的重要性,详细介绍红外成像和x射线数字成像两种氨制冷压力管道不停机检测技术。在氨制冷管道装配及使用过程中,只有严格执行最新国家相关的法律法规和最新技术,自觉按质保体系要求运作,氨制冷生产才有安全保证。