Numerical analysis on various models of pressure snubbers in the hydrogen gas compressing system

Abstract

This paper explains about numerical modeling of gas flow passing through a snubber, pulsation damper, in a hydrogen gas compressor system. The verification of the preliminary model was done successfully by comparing it with experimental results. Numerical analysis for various snubber dimensions is the focus of this present study. Thirty models of snubber were created by varying snubber height and buffer angle, and then simulated with the real working condition of a hydrogen gas compressing system. The CFD code package used was a Star CD with transient analysis and k-/ high Reynolds number as the turbulence model. The study was done by comparing pressure loss and pressure pulsation, since these two parameters are the objective functions in snubber optimization. The best snubber is the one that has the minimum pressure loss and pressure pulsation. Numerical result shows that the pressure loss grows with the increment of snubber volume. To the contrary, however, the pressure pulsation is decreased. Determining the buffer angle as the adjusted variable, the minimum pressure loss occurred at 30 o . But pressure pulsation trend was escalating.

Numerical simulation of pressure pulsation effects of a snubber in a CNG station for increasing measurement accuracy

“…This standard covers the lowest needs for reciprocating Figure 1. Schematic of a snubber (Jeong et al, 2008). compressors and their drivers for utilization in the gas, petroleum and chemical industries.…”

“…The main objective of this article is to decrease the pressure pulsations at the inlet of the snubber. Thus three equations are defined as below (Jeong et al, 2008):…”

“…In addition, A, A red , A in and A out are the percentage of pressure pulsation amplitude related to the line pressure, percentage of pressure pulsation drop, pressure pulsation amplitude of inlet and pressure pulsation amplitude of outlet. Decrease in pulsations means a decrease in A (Akbar, Shim, Yi, Lee, et al, 2006;Jeong et al, 2008).…”

“…According to the numerical data, air admission from a spindle hole reduced the difference in the pressure in the draft tube horizontal part, which in turn reduced the amplitude of low-frequency pulsation of pressure in the draft tube; the nitration of rotor-stator between the runner and air inlet resulted in an increment in the pressure pulsation of the blade-frequency in front of the runner. Jeong et al (2008) explained the numerical investigation of gas flow moving via a snubber in a hydrogen gas compressor unit. In their study, 30 snubber models were generated by changing the height of the snubber angle of buffer.…”

Analysis of Effect and Mechanism of Different Type Buffer for Reducing Pressure Pulsation

“…There are many measures that can be used to control the pressure pulsation of the pipelines,installing buffer beside the outlet of the compressor is an effective way.The seventies of last century, the former Soviet union experts analyzed the cause of vibration of pipelines systematically and comprehensively,and raised methods to reduce the pressure pulsation [1].Combined with experiment and theory analysis,Xian's Jiaotong university' experts transform sections of pipelines into different transition matrix proceeding from wave propagation,and write programs to calculate pressure pulsation and natural frequency of complex pipelines [2] . In recent years,computational fluid dynamics developed rapidly,study of flow field and effect of buffer used CFD increases gradually.Different buffers have different effect in reducing pressure pulsation,this can be accounted from their inner flow field,and inner structure will affect the property,optimization can be obtained through changing the inner structure parameter [3] [4].…”