The Finite Element Research Of The Ultra-high Pressure Natural Gas Compressor Cylinder

In the LNG shipping industry,natural gas has a large amount of traffic,a wide range,and a long distance.The power consumption of the transmission process is large.The ultrahigh-pressure natural gas compressor is an important special-purpose mechanical device that provides power for natural gas transmission.With the development of natural gas transmission in the direction of modernization and remoteness,the demand for working pressure on natural gas compressors has been increasing.The cylinder is an important component of the UHP natural gas compressor.Its reliability and safety directly determine the safety of the natural gas compressor.Therefore,the key research on the cylinder is a key task.In this paper,for the 35 MPa ultra-high pressure natural gas compressor,the structure of its high-pressure cylinder is calculated and analyzed.This article mainly studies from the following aspects:Firstly,the research status of the high-pressure cylinder structural performance field at home and abroad was investigated and the failure modes of fatigue,crack,wear,etc.of the natural gas compressor cylinder were studied.It was determined that this paper will use material mechanics,fracture mechanics,pressure vessels,thermodynamics,and machinery.Theory of vibration and airflow pulsation,and related finite element research.Secondly,according to variational method,virtual displacement method,element displacement method and stress-strain method,the assumptions of elastic deformation of the body,infinitesimal deformation,stress and strain strictly following Hooke’s law,etc.,are put forward and analyzed.The basic principles of thermodynamics such as heat conduction,thermal convection,and thermal radiation are also briefly introduced.The function and use of ANSYS software in this article are also introduced.Then it explains the process of establishing the cylinder finite element model,including the simplification and introduction of the model,parameter setting and meshing,etc.The next step is to calculate various cylinder load and boundary conditions,including bolt preload,high pressure gas force,and heat.Boundary conditions,etc.,provide conditions for setting the high-pressure cylinder finite element model in ANSYS.Focused on the high-pressure cylinder finite element results.Considering the statics,thermodynamics and the coupling of the two cylinders,the finite element stress-strain analysis of the cylinder of the UHP natural gas co mpressor was carried out based on ANSYS.Under the working conditions of the compressor crankshaft with different angles,the periodic dynamic stress-strain condition of the ultra-high-pressure cylinder was simulated,and the dynamic change law of the cylinder was obtained approximately.Finally,based on the finite element analysis,the optimization design of the cylinder structure of the UHP natural gas compressor was carried out based on the cylinder casing process size and the cooling water hole structure size of the cylinder block.For a better cooling effect and sufficient cylinder strength to do a useful exploration.