Manifolds play a role of pressure balance, buffering and rectification for different branch pipelines, the flow noise of manifolds has been a serious problem all this time in natural gas transmission station. By changing the number of outlet pipes of manifolds and the different positions of intake pipes, the distribution of the Sound Pressure Level (SPL) of the manifold flow noise is analyzed based on the Ffowcs Williams-Hawkings (FW-H) acoustic analogy theory and Large Eddy Simulations (LESs). The three-dimensional simulation analysis of the flow field shows that pressure pulsation is the mainly source of manifold noise, as the number of outlet pipe increases, the SPLs of fluid dynamic noise at the end of inlet pipes are significantly reduced by about 10 dB on average, when the inlet and outlet piping are oppositely connected, the SPL is 2 dB~3 dB lower than that in staggered connections. An expansion-chamber muffler is designed with the analysis of its noise reduction effect, the results show that after the muffler is installed, the noise reduction in the low-frequency ranges reaches up to 37.5 dB, which controls the maximum noise to around 82 dB.

The abnormal vibration of natural gas station pipelines seriously threatens the safety of pipeline transportation, and improper handling will cause huge economic losses. For the abnormal vibration of the pipeline, reasonable treatment must be carried out. The Yongchang gas station belongs to the west–east gas pipeline system in China. Since its production, abnormal vibration has often occurred in the west-third outbound pipeline of the Yongchang gas station, and the vibration changes according to the different gas transport volumes. In this paper, the outbound pipeline of the Yongchang pressure station is taken as the research object, and the vibration analysis of the station yard pipeline is carried out. The numerical model of the station yard pipeline is established, and the correctness of the model is verified by the field vibration test. The fluid–solid coupling method is used to analyze pipeline vibration under different working conditions. Then, three kinds of vibration reduction schemes are proposed and verified by simulation. The main conclusions are as follows: (1) The fluid pressure fluctuation in the pipeline is the root cause of abnormal vibration in the station. (2) When the gas transmission volume is large, the vibration of the pipeline system will become more severe. (3) The scheme of increasing pipe diameter and adding appropriate constraints has the best vibration reduction effect.

As an important medium transmission element, the pipeline has a very important application in the chemical industry, electric power industry, and petroleum industry. However, the pipeline vibration problem has seriously restricted the large-scale development of equipment, reduced the reliability of equipment operation, and even caused serious accidents. Therefore, it is very important to analyze the dynamic characteristics of these vibrations and to reduce the impact of vibrations within pipelines. We focus on the problem of abnormal vibrations within the JYG compressor station pipeline and use a 3D calculation model of the launcher pipeline of west−east gas pipeline III to perform simulation analysis using Fluent to find the cause of the abnormal vibrations. Our results show that the fluid pressure fluctuation in the pipeline is the main factor for the abnormal vibration of the launcher pipeline in the JYG compressor station. The main causes of the vibrations are excessive fluid flow and high flow velocity. Also, by comparing and analyzing the natural frequency of the pipeline system and the pressure fluctuation frequency of the vortex core in the pipeline, we found that the pressure fluctuation frequency is close to the low-order natural frequency of the pipeline system, which is prone to resonance. In this paper, three vibration reduction schemes of the JYG compressor station are suggested and verified. The efficiency of vibration reduction is 68−94%, which can be effectively applied to the outgoing pipeline of the west−east gas pipeline III to solve the abnormal vibration problem of the pipeline.