Analysis of Vertical Vibration Mechanism of Reciprocating Compressors considering Flexibility of Piston Rod and Crosshead Subsidence

Shouguo Cheng,Shulin Liu,Dong Li,Xin Sun,Shungen Xiao

doi:10.1155/2019/2747205

Abstract

This paper is targeted on the vertical vibration of the crosshead in a reciprocating compressor, taking into consideration the crosshead subsidence. The traditional model of the compressor is usually a crank-slider mechanism system without considering the abrasion loss for any parts, thus neglecting the influence of the piston rod flexibility. A rigid-flexible model of slider-crank is described theoretically, in which the crank, connecting rod, and crosshead are treated as rigid bodies, while the piston rod connected to the crosshead is considered as a flexible body. Lagrange equation was adopted to establish the kinetic equation of the system, considering the mass of the crank, the linkage, and the crosshead. After modeling the mechanism, the simulation shows that the dynamic response of the crosshead will be greatly influenced if crosshead subsidence is considered. Additionally, the influence of the crosshead subsidence is also investigated, and some new phenomena arise especially the vertical vibration of crosshead.

Highlights

A reciprocating compressor is one of the most widely used machines in petroleum and chemical production processes, such as gas compression and natural gas transportation [1]
There has been no efficient solution revealing the failures based on vibration signal of shell due to the lack of transferring mechanism of fault information
The purpose of this paper is to reveal the intrinsic influences of the crosshead when crosshead subsidence is taken into consideration

Summary

Introduction

A reciprocating compressor is one of the most widely used machines in petroleum and chemical production processes, such as gas compression and natural gas transportation [1]. There has been no efficient solution revealing the failures based on vibration signal of shell due to the lack of transferring mechanism of fault information. The behavior of kinetics and some fault information are highly nonlinear, leading to the fact that theories suitable for rotating machines are not appropriate for reciprocating compressors [2]. The key parts of reciprocating compressors are inside the body, which is difficult to approach and test. How the vibration signals transfer in the whole process is still uncertain, there are already some conclusions about the transferring routes. Extractions of fault signals are sometimes aimless and blind. There are so many origins of vibrations in the system of reciprocating compressor, which is the reason why the extractions of proposed signal are often a difficult task and lack precision

Objectives

Results

Conclusion