Research on Sealing Performance in High Pressure Oil-Free Miniature Air Compressor

2017 ◽  
Author(s):  
Yipan Deng ◽  
Yinshui Liu ◽  
Fan Li ◽  
Pengyun Tian ◽  
Na Miao
Keyword(s):  
Mathematical Model ◽  
High Pressure ◽  
Pressure Distribution ◽  
Research Work ◽  
Piston Rings ◽  
Premature Failure ◽  
Air Compressor ◽  
Sealing Performance ◽  
Rotary Speed ◽  
Discharge Pressure

High pressure oil-free miniature air compressor has an irreplaceable role in some high demand areas such as cooling, scuba diving and pneumatic catapult due to its remarkable advantages such as compacted size, lightened weight and clean output gas. As the important sealing component in the high pressure oil-free miniature air compressor, piston rings hold the properties such as tiny diameter (less than 10mm), high sealing pressure (up to 410 bar) and high surrounding temperature (up to 500K), which make them distinctive from conventional piston rings. A mathematical model was established to simulate the pressure distribution of the compressor chamber, as well as the gap between the sealing rings. Sensitive parameters were considered to investigate their effects on the sealing performance such as the number and the cut size of the piston rings, the suction and discharge pressure and the rotary speed. The mathematical model was verified by comparing to published experimental research work. These work help to reveal the severe non-uniformity of the pressure distribution of different chambers, which were suggested be the primary cause of the premature failure of the sealing rings, thus improving the sealing performance and the service life of the air compressor.

Study of the Pressure Distribution between the Piston Rings in Reciprocating Compressors

2011 ◽  
Vol 383-390 ◽  
pp. 6048-6052
Author(s):  
Dian Bo Xin ◽  
Jian Mei Feng ◽  
Yan Jing Xu ◽  
Xue Yuan Peng
Keyword(s):  
Pressure Distribution ◽  
Piston Ring ◽  
Dynamic Pressure ◽  
Threshold Value ◽  
Piston Rings ◽  
Premature Failure ◽  
Root Cause ◽  
Pressure Distributions ◽  
Start Up ◽  
Set Up

Piston ring is one of the most important sealing components that can be easily damaged in reciprocating compressors. The severe non-uniformity of the pressure distribution was suggested to be the essential reason for the premature failure of the piston rings. Therefore, a test rig was set up to measure the pressure distributions as well as the build-up of the dynamic pressure difference, which could reveal the root cause for the non-uniformity of the pressure distributions. The results showed that the build-ups of the pressure differences between different rings were not simultaneous; there existed a threshold pressure, and the latter ring could work only when the pressure before the former ring reached to the threshold value. The pressure distributions were also investigated at the start-up and shut-down of the compressor, which further validated the cause of the premature failure of the first ring.

Experimental investigation of pressure distribution between the piston rings and its formation in reciprocating compressors

2012 ◽  
Vol 226 (11) ◽  
pp. 2701-2712 ◽  
Author(s):  
Dianbo Xin ◽  
Jianmei Feng ◽  
Liqing Ding ◽  
Donghui Yang ◽  
Xueyuan Peng
Keyword(s):  
Pressure Distribution ◽  
Pressure Difference ◽  
Piston Ring ◽  
Dynamic Pressure ◽  
Experimental Results ◽  
Suction Pressure ◽  
Piston Rings ◽  
Ring Groove ◽  
Premature Failure ◽  
Contact Position

The severe non-uniformity of pressure distribution has been suggested as the essential reason for the premature failure of piston rings in reciprocating compressors. A test rig was built to investigate the dynamic pressure distribution and its formation process, so that the root cause of the non-uniform pressure distribution could be revealed. The experimental results showed that the pressure distribution between the rings was always significantly non-uniform under various test conditions and the first ring bore more than 75% of the total pressure difference. Further analysis of the experimental data indicated that when the suction pressure was not higher than that in the crank case, the first piston ring switched its contact position with the piston ring groove twice in one cycle, at the angles of around 63° and 170°, respectively, while the others switched contact positions at about 90° and 270°. If the suction pressure was higher than the pressure in the crank case, the first ring still switched its contact position twice in a cycle, at the crank angle of about 47° and 195°, respectively, but the other rings no longer changed their positions. The experimental results also demonstrated that the formation of pressure difference on different rings was not synchronous, which indicated that the rings could not work until their pressure difference reached a critical value.

Influence of pressure distribution in the gap of piston-cylinder unit and properties of working fluid PES-3 on characteristics of high pressure piston-cylinder unit

2020 ◽  
pp. 38-42
Author(s):  
A. E. Aslanyan
Keyword(s):  
Mathematical Model ◽  
High Pressure ◽  
Pressure Distribution ◽  
Pressure Range ◽  
Pressure Change ◽  
Working Fluid ◽  
Research Results ◽  
Piston Cylinder ◽  
Pressure Distributions ◽  
The Mathematical Model

A simulation of the use of PES-3 liquid in a high-pressure piston-cylinder units was performed, and the parameters of the piston-cylinder units were determined in the article. The equations of the mathematical model describing the pressure change in the gap between the piston and the cylinder are given. As a result of the calculations, the pressure distributions in the gap between the piston and the cylinder are determined at under piston pressures less than 1.6 GPa. The profiles of the gaps between the deformed piston and cylinder at different under piston pressures are calculated. The dependences of the speed of lowering the piston and the effective gap on the under piston pressure at different gaps of the undeformed piston-cylinder unit are obtained. The research results can be used in the design of piston cylinder units operating on PES-3 liquid in the pressure range of 0.01–1.6 GPa.

The Numerical Analysis of the Velocity and Pressure Distribution of the Oil Film in Heavy Hydrostatic Thrust Bearing

2014 ◽  
Vol 541-542 ◽  
pp. 658-662
Author(s):  
Jian Li ◽  
Yuan Chen ◽  
Yang Chun Yu ◽  
Zhu Xin Tian ◽  
Yu Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Pressure Distribution ◽  
Working Conditions ◽  
Thrust Bearing ◽  
Rotation Speed ◽  
The Other ◽  
Surface Load ◽  
Oil Film ◽  
Volume Method

To study the velocity and pressure distribution of the oil film in a heavy hydrostatic thrust bearing, a mathematical model of the velocity is proposed and the finite volume method (FVM) has been used to simulate the flow field under different working conditions. Some pressure experiments were carried out and the results verified the correctness of the simulation. It is concluded that the pressure distribution varies small under different rotation speed when the surface load on the workbench is constant. But the velocity of the oil film is influenced greatly by the rotation speed. When the rotation speed of the workbench is as quick as enough, the velocity of the oil film on one radial side of the pad will be zero, that is to say the lubrication oil will be drained from the other three sides of the recess.

A Study of the Sealing Performance of a New High-Pressure Cone Valve for Deep-Sea Gas-Tight Water Samplers

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Shi-Jun Wu ◽  
Can-Jun Yang ◽  
Ying Chen ◽  
Yan-Qing Xie
Keyword(s):  
Finite Element Analysis ◽  
High Pressure ◽  
Deep Sea ◽  
Hydrothermal Fluid ◽  
Contact Model ◽  
Element Analysis ◽  
Sea Trial ◽  
Sealing Performance ◽  
Pressure Cone ◽  
Gas Tight

The cone valve plays an important role in high-pressure sealing applications. In this paper, a new high-pressure cone valve, based on the titanium alloy poppet-to-polyetheretherketone seat sealing structure, is proposed for deep-sea gas-tight water samplers. In order to study the sealing performance of the new valve, both the conforming poppet-seat contact model and the nonconforming poppet-seat contact model were evaluated. Finite element analysis based on the two models was performed and validated by experiments. The results indicate that the nonconforming poppet-seat contact model has a better sealing performance than the conforming poppet-seat contact model. The new cone valve also was applied in a gas-tight hydrothermal fluid sampler and successfully tested in a sea trial during the KNOX18RR cruise from 9 July to 12 August 2008.

The Seepage Pressure Distribution and the Capacity of Low-Permeability Reservoirs Gas

2013 ◽  
Vol 734-737 ◽  
pp. 1317-1323
Author(s):  
Liang Dong Yan ◽  
Zhi Juan Gao
Keyword(s):  
Mathematical Model ◽  
Pressure Distribution ◽  
Low Permeability ◽  
Flow State ◽  
Klinkenberg Effect ◽  
Gas Reservoirs ◽  
Gas Well ◽  
Seepage Pressure ◽  
Slippage Effect ◽  
Low Permeability Reservoirs

Low-permeability gas reservoirs are influenced by slippage effect (Klinkenberg effect) , which leads to the different of gas in low-permeability and conventional reservoirs. According to the mechanism and mathematical model of slippage effect, the pressure distribution and flow state of flow in low-permeability gas reservoirs, and the capacity of low-permeability gas well are simulated by using the actual production datum.

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